2010 Edition Power Cables and Wires Technical Manual

2010 Edition

Power Cables & Wires Technical Manual

Through the initiative of: International Copper Association – South East Asia

Institute of Integrated Electrical Engineers of the Philippines, Inc.

ISBN 978-971-93962-8-4

PREFACE This book, Power Cables and Wires Technical Manual, was written to address the need by consumers, specifiers, and purchasers to have a ready reference guide in correctly specifying or ordering the appropriate cables and/or wires that will satisfy their particular requirements. Towards this purpose, a Cable/Wire Ordering Form, which appears in Annex D, was developed so that the User will be able to indicate and itemize his needs and give all data and information necessary for the Wires and Cable Manufacturer or Supplier to be able to supply the wire or cable that the User requires. All components necessary for the construction of a cable or wire, from the conductor to the insulator, are each discussed in this manual so as to educate or inform the reader of its fundamental use or purpose to the final product. Moreover, all the different types of material and their characteristics have been identified and explained in this manual to further elucidate the reader. This publication was made possible through the initiative and support of the International Copper Association – South East Asia and the Institute of Integrated Electrical Engineers of the Philippines, who developed, published and will propagate its use as reference. Though conscientious efforts have been exerted to ensure the accuracy of the information in this manual, comments regarding errors and omissions are most welcome and highly appreciated. All suggestions will be studied and considered for inclusion in this manual’s next edition.

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ACKNOWLEDGEMENT This “Power Cables and Wires Technical Manual” was developed into a printed publication through the collaborative efforts among professional, business and international organizations. In the course of the manual’s conceptualization, development and production, which spanned for more than a year, several distinguished entities and individuals, have generously lent their utmost participation, assistance, knowledge, expertise and support towards the completion and publication of this manual. Special thanks are given to the Institute of Integrated Electrical Engineers (IIEE) of the Philippines’ 2009 and 2010 Board of Governors, headed by their Presidents, Engrs. Arthur N. Escalante and Gregorio Y. Guevarra, respectively, for their insightful approval to engage the Institute in this worthwhile project and sustaining the support until its completion. Of course, all of this would not have been possible without the initiative and patronage of the International Copper Association – South East Asia, whose representative in the Philippines is Mr. Jessie Todoc. Further, we want to recognize the critical support, knowledge and relevant materials contributed by the following Wires and Cables Companies; Columbia, Phelps Dodge, Sycwin and Philflex. Moreover, we would like to acknowledge the Bureau of Product Standards (BPS) of the Department of Trade and Industry (DTI) for the list of the existing Philippine National Standards (PNS) on wires and cables. Finally, eternal gratitude is given to the IIEE Adhoc Committee on Wires and Cables, whose members are; Engr. Willington K. K. C. Tan, Engr. Cesar Gatpo, Ms. Maritess Templonuevo and Engr. Ricardo Lopez Jr., who participated in the conceptualization and outline of the manual and were instrumental in coming up with the Cable/Wire Ordering Form, and whose indefatigable Chairman, Engr. Arthur A. Lopez, gave flesh to the manual. Special mention is given to Engr. Feldimir Siao of MERALCO, who conducted the review of the original manuscript and to Engr. Wilson Yu for his valuable contributions. Again, thank you very much. v

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Table of Contents Preface Acknowledgement Table of Contents Introduction 1 Material Consideration 1.1 Resistance and Conductivity 1.2 Weight 1.3 Amapacity 1.4 Voltage Regulation 1.5 Short Circuit 1.6 Other Factors 2 Wire/Cable Manufacturing Process 2.1 Drawing 2.2 Annealing 2.3 Stranding 2.4 Bunching 2.5 Extrusion 3 Conductor Size 4 Stranding 4.1 Concentric Stranding 4.2 Compressed Stranding 4.3 Compact Stranding 4.4 Bunch Stranding 4.5 Rope Stranding 4.6 Sector Conductors 4.7 Segmental Conductors 4.8 Annular Conductors 5 Physical and Mechanical Properties 5.1 Conductor Properties 5.2 Tempers of Conductors 5.3 Conductor Direct Current (DC) Resistance 5.4 Conductor AC Resistance 5.5 Cables in Magnetic Metal Conduit 5.6 Resistance at Higher Frequency

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iii v vii 1 1 2 3 4 4 4 4 5 6 6 6 6 7 7 10 10 11 11 13 13 13 13 14 14 14 15 16 19 21 22

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Insulation 6.1 Elastomers 6.2 Plastics 6.3 Insulation Resistance 7 Cable Design and Construction 8 Low Voltage Wires and Cables 8.1 Building Wires 8.2 Secondary and Service Cables 9 Medium and High Voltage Wires and Cables 9.1 Bare Conductors 9.2 Covered Conductors 9.3 Insulated Cables 10 Installation of Wires and Cables 10.1 Maximum Allowable Tensions on Conductors 10.2 Sidewall Pressure 10.3 Bending Radius 11 Packaging 12 Cable/Wire Application 13 Cable Installation Method 14 Color Coding 15 Reference Standards 16 Storage 17 Available Cable Handling Equipment at Site 18 Safeguards for Installing Wires and Cables in Conduit 18.1 Before Pulling Wire/Cable 18.2 While Pulling Wire/Cable 18.3 After Pulling Wire/Cable 19 Safeguard for Switchboard and Similar Open Wiring 20 Wire/Cable Ordering Form Annexes Annex A Annex B Annex C Annex D Bibliography

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22 23 27 33 35 36 39 44 49 49 53 57 62 62 68 69 72 72 72 72 73 73 75 75 76 76 76 76 77 79 81 157 165 171 173


INTRODUCTION One of the fundamental concerns of electrical engineering is the transmission and distribution of electricity to its final utilization in a manner that is safe, efficient and economical. The choice of conductor material including size and design takes into consideration the operating voltage, ampacity, mechanical properties, type of installation and overall cost. Electric wires and cables come in a wide variety of types and construction. It usually consists of a low resistance conductor to properly transmit electric current. They can be classified in various ways depending on the factors being considered such as the material, degree of insulation, service, or voltage application. The aim of this manual is to provide sufficient information on the types of wires and cables available in the market including its intended application in order for the reader to make an intelligent selection. At the end section of this manual, more detailed information are included on the types and applications of wires and cables that an electrical practitioner would generally need. 1. MATERIAL CONSIDERATIONS There are several high conductivity metals that may be used as conductor. A conductor is a metallic material which allows electric current to flow through it with less resistance. Table 1 ranked these metals according to resistivity at 20°C. The best conductor material is silver but due to its high cost per unit weight and being one of the precious metals, it is not economical to use in the transmission and distribution of electricity. Comparatively, gold with its excellent corrosion resistance and lower resistivity than aluminum is also a good conductor but, same as silver, is very costly. Thus, these metals i.e., silver and gold are only used in electrical applications where low resistivity and corrosion resistance is of utmost importance such as electrical contacts. 1


Copper with its inherent lower resistivity than aluminum is the preferred conductor on certain applications. It is malleable and ductile. Also, it has a relatively higher tensile strength and easily soldered. However, it is more expensive and heavier than aluminum.

Table 1. Resistivity of Metals at 20°C Metal Ohm-mm2/m Silver 1.59×10−8 Copper 1.68×10−8 Gold 2.44×10−8 Aluminium 2.82×10−8 Tungsten 5.60×10−8 Zinc 5.90×10−8 Nickel 6.99×10−8 Iron 1.0×10−7 Platinum 1.06×10−7 Tin 1.09×10−7

1.1 Resistance and Conductivity Resistance is the opposition of an object to the passage of electric current. For direct current, resistance is dependent on the material length, cross-sectional area and resistivity. The electrical resistance of a conductor is inversely proportional to the cross-sectional area or diameter of a conductor i.e., the larger the conductor the less resistance it has to the flow of current. Conductivity, on the other hand, is the complete opposite of resistance. Compared with copper, aluminum has a number of technical disadvantages, all of which can be satisfactorily overcome to benefit from its economic attraction. The advantage of its lower density (about one-third that of copper) is partly offset by its low conductivity of just 61% that of copper. Thus, an aluminum conductor must have a cross-sectional area about 1.6 times that of copper conductor to have the equivalent dc resistance. Such difference is approximately equal to two sizes higher (i.e., in AWG). 2


The grade and quality of copper is very important and the high conductivity copper used for electrical purposes comfortably exceeds the 100% IACS (International Annealed Copper Standard) value. Conductivity is greatly influenced by impurities and by mechanical working. Consequently, the purity is of the order of 99.99%, which nowadays is obtained by final electrolytic refining. Fortunately, the mechanical strength of annealed copper wire is adequate for nearly all types of insulated cable. If any minor working of the material occurs during conductor manufacture, e.g. in compacting to reduce the overall dimensions, allowance has to be made for work hardening by increasing the copper volume to compensate for the reduction in conductance. In an extreme case, such as the use of hard drawn copper for self-supporting overhead lines, this may amount to as much as 3%. Copper is invariably used in the annealed condition except for the conductors of selfsupporting overhead cables. Solid aluminum conductors are also mainly in a soft condition but stranded aluminum conductors are ¾ H (hard) to H. 1.2 Weight Although aluminum has only about sixty-one percent (61%) of the conductivity of copper, its lightness makes long spans possible. Aluminum’s low density is one of its important advantages. Also, its relatively large diameter for a given conductivity reduces corona (the discharge of electricity from the wire when it has a high potential), which contributes to the losses of the wire. This makes aluminum ideal for the transmission of high voltage power over long distances. However, due to aluminum’s relatively low tensile strength, the aluminum conductors are usually cabled around a steel support wire to improve the total tensile strength of the cable. This enables the relatively expensive transmission towers to be spaced further apart without the wire sagging too much. Electrical transmission lines are the largest users of aluminum wire products. In fact, this is the one market in which aluminum has virtually no competition from other metals. However, the relatively large size of aluminum for a given conductance does not permit the economical use of an insulation 3

Power Cables & Wires Technical Manual covering. Hence, low voltage household, office, and factory electric wires and cables are usually copper, which also does not have the corrosion problems common to aluminum wires. In fact, copper has been unchallenged as a conductor for all types of insulated cables for well over seventy (70) years. 1.3 Ampacity In general, current ratings of aluminum cables are about 78%-80% of those of copper cables of the same conductor size. An aluminum cable needs to be thicker than a copper cable in order to have the same current carrying capacity. 1.4 Voltage Regulation Reactance is negligible in all DC circuits and, in AC circuits with small conductors of sizes equal to or less than 60 mm2. Voltage drops for a copper conductor and an aluminum conductor with 1.6 times the cross-sectional area would be the same. However, in AC circuits with large conductors, the resistance value is influenced by skin and proximity effect, and the reactance becomes important. 1.5 Short Circuit Copper conductors have higher capabilities in short circuit operations than aluminum conductors. However, for covered and insulated conductors the thermal limitations of the materials which form part of conductor should be considered before making such comparison. 1.6 Other Factors Aluminum oxidizes rapidly when exposed to air, a thin corrosion resistance film having a high dielectric strength forms quickly. Thus, additional care must be taken when making connections. Material of terminal connections should be taken into consideration since this could corrode the aluminum conductor. Also, when a combination of copper and aluminum conductors are to be connected together, special technique or connectors are required to have a reliable connection. 4


Small strands of aluminum conductor have lower bending tolerance that these are not used in generating stations, substations or portable cables. When there are space limitations, copper cables are the suitable choice since aluminum cables are larger in size for the same current carrying capacity. Economics does play a vital consideration in the choice of conductor but should include the other overlying cost involved to complete an installation. 2. WIRE/CABLE MANUFACTURING PROCESS Copper and aluminum rods undergo several stages of processing before they become wires or cables. Below is a flowchart of the wire/cable manufacturing process. Bare solid hard drawn wire (1)

Extrusion (4)

Insulated solid hard drawn wire (1 & 4) Insulated stranded hard drawn wire (1, 3, 4)

Drawing (1)

Stranding/ Bunching (3)

Bare stranded hard drawn wire (1 & 3)

Annealing (2)

Stranding/ Bunching (3)

Bare stranded soft drawn wire (1, 2 & 3)

Bare solid soft drawn wire (1 & 2)

Extrusion (4)

Insulated stranded soft drawn wire (1, 2, 3 & 4)

Figure 1: Wire Manufacturing Process 5


2.1 Drawing Drawing is the process of pulling the copper or aluminum rods or wires at normal temperature through a die to reduce the crosssectional area in order to get the desired dimension. The wire is deformed due to the tapering of the die and the force exerted during pulling. 2.2 Annealing Annealing is the process of “softening” the temper of the wire and improving its cold working properties and machinability through sustained heating at a pre-determined temperature followed by cooling at a defined rate. There are many ways of annealing a wire; the most common practices in annealing copper is the continuous strand or resistance annealing wherein annealing is done by means of a machine placed between the final capstan of a drawing machine and the spooler so that the wire is drawn, annealed and spooled in one operation. 2.3 Stranding Stranding is the process where a number of hard or soft wires are laid together geometrically in such a way that each wire holds its place in the strand all throughout the entire length. Generally, the number of wires in a strand is 7, 19, 37, 61, and could reach up to 91, 127 or 168 depending on the desired size or cross-sectional area of the stranded wire. The lay of multi-layered stranded wires are laid in opposite direction alternately in its succeeding lay with the outermost generally being left-handed. 2.4 Bunching Bunching is similar to the stranding process except that all individual wires are twisted uniformly in the same direction without regard for geometrical arrangement. It provides a more flexible conductor than a single strand. A number of bunches twisted together in the same direction and in uniform manner is called a compound 6

Power Cables & Wires Technical Manual bunch. A number of bunches twisted together so that each bunch, except the central one, has a helical form of pre-determined lay ratio is a stranded bunch. A number of stranded bunches twisted together so that each stranded bunch, except the central one, has a helical form of pre-determined ratio is called a compound strand bunch. 2.5 Extrusion Extrusion is the process where an insulation material is continuously coated or applied around the conductor as it passes through a die in the head of an extruding machine. The insulation material in form of pellets, dice and the likes (can be plastic, nylon, rubber, etc.) are placed in a hopper that is situated over a barrel in which a screw revolves. The insulation material softens as it feeds inside the heated extruder barrel then melted out over the core material through the screw which forces the material along the barrel and compresses it at the same time to convert the material into fluid mass. The conductor emerges from the tip of the core with the material stream inside the extruder head and the insulation is formed to the required size and shape as the insulated conductor passes through the die. 3. CONDUCTOR SIZES Similar to most industries, standards for measuring conductor sizes had been developed. A conductor’s size is usually specified based on the conductor’s cross-sectional area or its diameter. Conductor sizes are usually identified in accordance with either of the two predominant wire sizes, the American Wire Gauge (AWG) which is originally known as Brown and Sharpe gauge (B&S) or the Metric Wire Gauge (MWG), which is the international standard (SI or IEC). The American Wire Gauge (AWG) is used predominantly in the United States of America (USA). The diameter of AWG No. 4/0 is 0.46 inch and the diameter of the AWG No. 36 is 0.005 inch. The other 38 intermediate sizes are governed by a geometric progression with the following formula:

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Power Cables & Wires Technical Manual Thus, the ratio of any diameter to the next size is 1.122932. The conductor diameter will approximately double after the next 6 AWG sizes or it will be half after the next 6 lower sizes. For conductor sizes larger than AWG No. 4/0, the size is expressed in circular mils which is an arbitrary cross-sectional area of the conductor. It is computed by multiplying the individual wire diameter in inches by 1,000, squaring the result, and multiplying by the number of wires. Usually expressed in kcmil (new term) or MCM (old term) which denotes thousand circular mils. The metric wire gauge is used by most countries in the world. It uses the SI unit of square millimeters (mm2) to designate conductor size (i.e., cross-sectional area). However, the designated metric wire sizes are not the precise sizes. IEC standard allows a variation of up to 20% in the conductor area from the designated size. In the Philippines, the wire sizes used are in metric but are, technically, based on AWG sizes. That is, the nearest metric equivalents to the crosssectional area of the standard AWG sizes were adopted. Solid conductor sizes are specified according to its diameter (mm), while stranded conductor sizes are specified according to its cross-sectional area (mm2). Table 2 shows the conversion table of the standard AWG sizes to their metric equivalences. A conductor’s size is directly proportional to its current carrying capacity. Hence, the bigger the size of the conductor, the higher the current it can carry or will be able to transmit for a given temperature. Annex A shows the current carrying capacity of the various sizes of bare and insulated, as well as, solid and stranded conductors according to their application and method of installation. For stranded conductors, the area is based on the sum of the crosssectional area of the individual strands. Stranding of conductors provide the desired properties of flexibility, however, it also increases slightly the overall diameter because of the small gaps between the strands. Hence, a stranded conductor will always have a slightly larger overall diameter than a solid conductor with the same size or gauge. 8


Table 2 - Conversion Table (Nearest AWG/kcmil to mm2) PEC (PNS) mm2 (mm. dia.) SOLID (1.6 mm) (2.0 mm) (2.6 mm) (3.2 mm) STRANDED 2.0 (7 x 0.6 mm) 3.5 (7 x 0.8 mm) 5.5 (7 x 1.0 mm) 8.0 (7 x 1.2 mm) 14 (7 x 1.6 mm) 22 (7 x 2.0 mm) 30 (7 x 2.3 mm) 38 (19 x 2.3 mm) 50 (19 x 1.8 mm) 60 (19 x 2.0 mm) 80 (19 x 2.3 mm) 100 (19 x 2.6 mm) 125 (37 x 2.1 mm) 150 (37 x 2.3 mm) 200

(37 x 2.6 mm)

250 325 400 500

(61 x 2.3 mm) (61 x 2.6 mm) (61 x 2.9 mm) (61 x 3.2 mm)

ASTM AWG/kcmil (mm. dia.) 14 12 10 8

(1.63mm) (2.05 mm) (2.59 mm) (3.26 mm)

14 12 10 8 6 4 2 1 1/0 2/0 3/0 4/0 250 300 350 400 450 500 600 750 1000

(7 x 0.615 mm) (7 x 0.775 mm) (7 x 0.978 mm) (7 x 1.23 mm) (7 x 1.56 mm) (7 x 1.96 mm) (7 x 2.47 mm) (19 x 1.69 mm) (19 x 1.89 mm) (19 x 2.13 mm) (19 x 2.39 mm) (19 x 2.68 mm) (37 x 2.09 mm) (37 x 2.29 mm) (37 x 2.47 mm) (37 x 2.64 mm) (37 x 2.8 mm) (37 x 2.95 mm) (61 x 2.52 mm) (61 x 2.82 mm) (61 x 3.25 mm)

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Metric (IEC) mm2 (mm. dia.)

2.5 4.0 6.0 10 16 25 35

(7 x 0.67 mm) (7 x 0.85 mm) (7 x 1.04 mm) (7 x 1.35 mm) (7 x 1.71 mm) (7 x 2.13 mm) (7 x 2.52 mm)

50

(19 x 1.8 mm)

70 95 120 150

(19 x 2.17 mm) (19 x 2.52 mm) (37 x 2.03 mm) (37 x 2.3 mm)

185

(37 x 2.52 mm)

240 300 400 500

(61 x 2.44 mm) (61 x 2.5 mm) (61 x 2.9 mm) (61 x 3.2 mm)

Power Cables & Wires Technical Manual 4. STRANDING The conductor material may be either solid or stranded. A solid conductor is a single, solid strand of conductor for the whole length of the wire, while a stranded conductor is composed of several strands of conductor concentrically wounded together over the whole length of the wire/cable. For the same cross-sectional area of a conductor, there are diameter differences between solid and various types of stranded conductors. This is an important consideration in the selection of connectors and in the methods of splicing and terminating. Large sizes of solid conductors are too rigid for many applications that the solution would be to have smaller wires and strand them together to form the conductor. There are several ways of stranding the wires together which is dependent of the type and temper of the metal used. The following subsections will discuss the most commonly used stranding for copper conductors. 4.1 Concentric Stranding This consists of a central wire or core surrounded by one or more layer of hellically applied wires. Each layer is applied in a direction opposite to the layer underneath, except for unilay construction wherein the layers are applied in the same lay direction. Lay length is the distance required to make one complete revolution of a strand around the central conductor. Lay length Concentric Stranding requirement based on the American Society of Testing Materials (ASTM) standard is for neither it to be not less than 8 times nor more than 16 times the overall diameter of that layer. For power cables, the standard stranding is Class B. The outermost layer should be of a left hand lay Left hand lay direction which means that when you go along the axis of the conductor the outermost layer of strands should roll towards the left as they recede from the observer. More 10

Power Cables & Wires Technical Manual flexibility is obtained by using small strands and increasing the number of wires in the conductor. Class C has one more layer than Class B, Class D has one more layer than Class C and so on. The class designation goes up to M (those normally used for welding cables). 4.2 Compressed Stranding This construction slightly deforms the layers to allow the layer being applied to close tightly. The diameter of the conductor can be reduced by up to 3% of the equivalent concentric strand. There is no, however, Compressed Stranding reduction in the conductor area. 4.3 Compact Stranding This is similar to compressed stranding except that additional forming is done to reduce the conductor diameter typically by 9% less than its equivalent concentric stranded conductor. The resulting diameter is a near solid conductor.

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Compact Stranding


Table 3 - Diameter for Stranded Copper and Aluminum Conductors Conductor Size

Nominal Diameters (mm) Concentric Stranded Compressed Class B Class C

Compact

AWG 8 3.708 3.759 3.581 3.404 6 4.674 4.742 4.521 4.293 4 5.893 5.944 5.715 5.410 3 6.604 6.680 6.401 6.045 2 7.417 7.518 7.188 6.807 1 8.433 8.458 8.179 7.595 1/0 9.474 9.500 9.169 8.534 2/0 10.643 10.668 10.312 9.550 3/0 11.938 11.963 11.582 10.744 4/0 13.411 13.437 13.005 12.065 kcmil 250 14.605 14.630 14.173 13.208 300 16.002 16.027 15.519 14.478 350 17.297 17.297 16.789 15.646 400 18.491 18.517 17.932 16.739 450 19.609 19.634 19.025 17.780 500 20.650 20.701 20.041 18.694 550 21.717 21.717 21.057 19.685 600 22.682 22.682 21.996 20.650 650 23.597 23.622 22.885 21.463 700 24.486 24.511 23.749 22.276 750 25.349 25.375 24.587 23.063 800 26.187 26.213 25.400 23.825 900 27.762 27.762 26.949 25.375 1000 29.261 29.286 28.372 26.924 Notes: 1. Compressed and compact nominal diameters are based on concentric lay stranded Class B construction. 2. The above diameters are based on ASTM specifications (converted into SI or metric units).

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4.4 Bunch Stranding In this construction the conductor strands are twisted together in the same direction without any regard to the geometric arrangement. Commonly used when very flexible wire is required for small conductor sizes, such as portable cables.

Bunch Stranding

4.5 Rope Stranding This is a combination of the concentric conductor and a bunch stranded conductor. The complete conductor is composed of a number of groups of bunched or concentric stranded conductors assembled concentrically together.

Rope Stranding

4.6 Sector Conductors The cross-section of these conductors is approximately the shape of a circle’s sector. A multi-conductor insulated cable with three sector conductor cables have three 120° segments that combine to form a circle as a finished cable. This cable have smaller Sector Conductor diameter than the cable with round conductors. Also, these cables have lower ac resistance due to a reduction of the proximity effect. 4.7 Segmental Conductors A segmental conductor is a round, stranded conductor composed of three or four sectors slightly insulated from one another. This construction has the advantage of lower a-c resistance due to less skin effect. Segmental Conductor 13


4.8 Annular Conductors The round stranded conductors are laid around a suitable core. The core is usually made wholly or mostly of non-conducting material. This construction has the advantage of lower total a-c resistance for a given cross-sectional area of conducting material by eliminating the Annular Conductor greater skin effect at the center. 5. PHYSICAL AND MECHANICAL PROPERTIES Although high conductivity is an important feature of a good conductor, there are other factors that must be considered. Silver maybe the most conductive material but high cost and lack of physical strength makes it inappropriate for commercial usage as wire and cable. Thus, the dominant metals used for wires and cables are copper and aluminum. 5.1 Conductor Properties Copper and aluminum has its own advantageous and disadvantageous characteristics that affect its use under varying circumstances. A comparison o f s o m e o f the characteristics of copper and aluminum is given in Table 4.

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Power Cables & Wires Technical Manual Table 4: Comparative Characteristics of Copper and Aluminum o CHARACTERISTICS (20 C) Ultimate Tensile Strength (MN/m2 ) soft temper ¾ H to H Hardness (DPHN) soft ¾ H to H Weight for the same conductivity (kg.) Cross section for the same conductivity (mm2) Weight Resistivity(Ohms-g/m2)

COPPER

ALUMINUM

225 385

70-90 125-205

50 115 45.4

20-25 30-40 21.8

0.05

0.08

0.153280

0.076149

Volume Resistivity (Ohms- mm2/m)

0.017241

0.028172

0.00393

0.00404

3.8 17.0 x 10-6

2.4 23.0 x 10-6

8890

2703

1,083

659

26

14

+/- 65

+/- 40

o

Temperature Coefficient of Resistance ( C) Thermal Conductivity (W/cm °C) Coefficient of Thermal Expansion per °C Density (kg/m3) o Melting Point ( C) Modulus of Elasticity (MN/m2) Stress Fatigue Endurance Limit (approximate) (MN/m2)

5.2 Tempers of Conductors Drawing copper or aluminum rods into a wire results in the hardening of the finished wire. This causes a soft temper rod to become a hard temper wire. It may be desirable to utilize a conductor of softer temper in cable construction. This can be achieved through an annealing process during or after wire drawing or stranding. Annealing consists of heating the conductor to elevated temperatures for specific time periods. This is usually done in an oven or by continuous resistance annealing at the drawing machine. Copper can be provided in three (3) tempers based on ASTM standards. These tempers are soft or annealed, medium-hard and hard-drawn. Soft or annealed is the most often used temper for 15

Power Cables & Wires Technical Manual insulated conductors due to its flexibility. Medium hard-drawn and hard-drawn tempers are most often used in overhead applications due to their higher breaking strengths. On the other hand, aluminum can be provided in five (5) tempers based on ASTM standards as shown in the Table 5, below. Note that the overlapping values showing the same conductor may meet the temper requirements of two classifications. Table 5 – Tensile Strength of the Different Temper Classifications of Aluminum Classifications of 1350 Aluminum Full Soft ¼ Hard ½ Hard ¾ Hard Full Hard

(H-0) (H-12 or H-22) (H-14 or H-24) (H-16 or H-26) (H-19)

Tensile Strength (in kg/cm2) 597.6 to 984.3 843.7 to 1195.3 1054.7 to 1406.2 1195.3 to 1546.8 1582 to 2039

Three quarters and full hard are the most common tempers used with 1350 aluminum for insulated conductors. Full hard drawn temper is most often used in overhead applications due its higher breaking strengths. 5.3 Conductor Direct Current (DC) Resistance The DC resistance (Rdc) of a conductor of uniform cross section can be computed as:

where, l = A= ρ=

length of the conductor, meters (m) cross-sectional area of the conductor, square meters (m2) (Greek: rho) electrical resistivity (also called specific electrical resistance) of the material, ohm-meters (Ω-m) ρ for copper is 1.678 x 10-8 Ω-m at 20°C ρ for aluminum is 2.65 x 10-8 Ω-m at 20°C 16


Since resistance is temperature dependent, conversion of a given resistance at a specified temperature to another is given by these formulas: Copper: where, R2 = R1 =

Aluminum: conductor resistance at temperature T2 in °C conductor resistance at temperature T1 in °C

These formulas are based on the resistance coefficient of copper having 100% conductivity and aluminum having 61.2% conductivity based on International Annealed Copper Standard (IACS).

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Power Cables & Wires Technical Manual Table 6 - DC Resistance in Ohms Per Kilometer at 25oC Size AWG or kcmil

Solid Copper *Uncoated

Aluminum

8 6 4 3 2 1 1/0 2/0 3/0 4/0 250 300 350 400 450 500 550 600 650 700 750 800 900

2.099 1.322 0.830 0.659 0.552 0.413 0.328 0.260 0.207 0.164 — — — — — — — — — — — — —

3.444 2.168 1.361 1.079 0.856 0.679 0.538 0.426 0.338 0.269 0.228 0.190 0.162 0.142 0.126 0.114 — — — — — — —

Concentric Lay Stranded Copper Aluminum *Uncoated Class B, C Class B, C 2.139 3.510 1.348 2.214 0.846 1.391 0.672 1.102 0.531 0.872 0.423 0.692 0.335 0.551 0.266 0.436 0.211 0.344 0.167 0.274 0.141 0.232 0.118 0.194 0.101 0.166 0.088 0.145 0.079 0.129 0.071 0.116 0.064 0.105 0.059 0.097 0.054 0.089 0.051 0.083 0.047 0.077 0.044 0.072 0.039 0.064

1000

—

—

0.035

0.058

*Uncoated – without tin or lead covering

The resistance values of the different conductor sizes in Table 6 are applicable only when Direct Current (DC) is flowing through the conductors.

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Power Cables & Wires Technical Manual 5.4 Conductor AC Resistance When Alternating Current (AC), at sixty Hertz (60 Hz), is flowing through said conductors, the DC resistance values have to be multiplied with the corresponding correction factor (Table 7) to obtain the AC resistance values of the different conductor sizes. Table 7 - Multiplying Factors for Converting D.C. to A.C. Resistance

Size

Up to 3 2 1 0 00 000 0000 250 300 350 400 500 600 700 750 800 1000 1250 1500 1750 2000

Multiplying Factor For Non-metallic Sheathed For Metallic Sheathed Cables in Air or Non- Cables or all Cables in metallic Conduit Metallic Raceways Copper Aluminum Copper Aluminum 1.000 1.000 1.00 1.00 1.000 1.000 1.01 1.00 1.000 1.000 1.01 1.00 1.001 1.000 1.02 1.00 1.001 1.001 1.03 1.00 1.002 1.001 1.04 1.01 1.004 1.002 1.05 1.01 1.005 1.002 1.06 1.02 1.006 1.003 1.07 1.02 1.009 1.004 1.08 1.03 1.011 1.005 1.10 1.04 1.018 1.007 1.13 1.06 1.025 1.010 1.16 1.08 1.034 1.013 1.19 1.11 1.039 1.015 1.21 1.12 1.044 1.017 1.22 1.14 1.067 1.026 1.30 1.19 1.102 1.040 1.41 1.27 1.142 1.058 1.53 1.36 1.185 1.079 1.67 1.46 1.233 1.100 1.82 1.56

19

Power Cables & Wires Technical Manual If a conductor is carrying high alternating current, the distribution of the current is not evenly distributed throughout the cross-section of the conductor. This is due to two independent effects known as “Skin Effect” and “Proximity Effect”. 5.4.1 Skin effect Skin Effect is a natural phenomena in wires wherein alternating electric current (AC) tends to distribute itself within a conductor so that the current density near the surface of the conductor is greater than at its core. That is, the electric current tends to flow at the “skin” of the conductor, at an average depth called the skin depth. The skin effect causes the effective resistance of the conductor to increase with the frequency of the current. The higher the frequency the smaller is the skin depth. The skin effect is due to eddy currents set up by the AC current. The magnitude of the skin effect is influenced by the frequency, the size of the conductor, the amount of current flowing, and the diameter of the conductor. Skin depth varies as the inverse square root of the conductivity of the conductor material. This means that better conductors have a reduced skin depth. The overall resistance of the better conductor material is lower even though the skin depth is less. This tends to reduce the difference in high frequency resistance between metals of different conductivity. At 60 Hertz (Hz) in copper, skin depth is about a centimeter. At higher frequencies, skin depth is much smaller. Likewise, skin depth also varies as the inverse square root of the permeability (which is a macroscopic material property that relates or is the ratio of the magnetic flux density to the strength of the magnetic field that induces it) of the conductor material. In the case of iron, its conductivity is about 1/7 that of copper. Its permeability, however, is about 10,000 times greater. The skin depth of iron is about 1/38 that of copper or about 220 micrometers at 60 Hz. Iron wire, therefore, is worthless as a conductor at power line frequencies. Methods to minimize skin effect include using specially woven (braided) cable/wire and using hollow pipe-shaped conductors. 20


5.4.2 Proximity Effect The Proximity Effect is associated with the magnetic fields of two conductors, which are close together. If each carries a current in the same direction, the halves of the conductor in close proximity are cut by more magnetic flux than the remote halves. Consequently, the current distribution is not even throughout the cross-section, a greater proportion being carried by the remote halves. If the currents are in opposite direction, the halves in closer proximity carry the greater density of current. In both cases, the overall effect results in an increase in the effective resistance of the conductor. The proximity effect decreases with the increase in the spacing between cables. Skin and Proximity Effects can be ignored with small conductors carrying low currents. They become increasingly significant with larger conductors and it is often desirable for technical and economic reasons to design the conductors/cables to minimize them. Values of skin and proximity effects can be computed based on the formulas provided by IEC 60287-1-1. 5.5 Cables in Magnetic Metal Conduit Due to excessive hysteresis and eddy currents, all phases of an AC circuit should be installed in the same magnetic metal conduits. Never install individual phases in separate metal conduits under any circumstances due to the high inductance of such installation. Also, separate phases should not pass through magnetic structures since overheating would occur in such situation. All phases should pass through a magnetic enclosure together in order that there will be a cancellation of the resultant magnetic field. However, the proximity of the magnetic material will increase the skin and proximity effect. Thus, there can be significant losses when large conductors are near magnetic materials. Large cable sizes from 100 mm2 or larger should not be installed in separate non-magnetic metal conduit due to the high circulating currents in the conduit. The ampacity of the cables should be derated in such condition. 21


5.6 Resistance at Higher Frequency Ampacity and resistance of cables to be operated at frequencies higher than 60 hertz should be corrected. The inductive reactance increases at high frequencies which may affect the voltage drop. Insulated conductors should not be installed in metallic conduits or run close to magnetic materials. The correction factor for the resistance at frequencies other than 60 hertz is provided as follows:

where, f = Rdc =

frequency in hertz conductor DC resistance at operating temperature in Ohm/1000 ft

6. INSULATION Insulation is that part of the cable or wire which is relied upon to insulate the conductor from other conductors or conducting parts or from ground. Insulating materials are usually classified according to the temperature they are able to withstand. The applied insulation must perform adequately in the specified temperature range and its dielectric strength should be sufficient to sustain the electrical stresses. There are many insulating materials used in producing the various cables to deliver electric power depending on their temperature limits, such as cotton, silk, paper, mica, glass fiber, asbestos, rubber, silicone elastomer, etc. Sometimes insulating materials, such as cotton, silk and paper are impregnated or coated with a dielectric liquid, such as oil, to enhance their insulating capabilities.

22

Power Cables & Wires Technical Manual Cable insulation should have the following properties: 1. 2. 3. 4. 5.

High Dielectric strength Low Dielectric Constant Good mechanical capability Resistance to ageing High temperature withstandability

In recent times, synthetic polymers have replaced natural materials such as paper, mineral oil and natural rubber for the insulation of wires/cables and for the over-sheathing of cables. The range of polymers available is extensive and variations in chemical composition enable specific mechanical, electrical and thermal properties to be obtained. Where appropriate, these properties may be further modified by the addition of specific fillers, plasticizers, softness extenders, colorants, antioxidants and many other ingredients. In the cable industry, the term polymeric material is taken to signify polymers which are rubbers or plastics. Rubbers are considered to be solid materials, with elastic properties, which are made from latex derived from living plants or synthetically and used in the manufacture of rubber products. Plastics, on the other hand, are materials based on synthetic or modified natural polymers which at some stage of manufacture can be formed to shape by flow, aided in many cases by heat and pressure. These two material groups are the dominant means of insulating wires and cables. 6.1 Elastomers An elastomer is a material which returns rapidly to approximately its initial shape after substantial deformation at room temperature by a weak stress and release of that stress. In cable technology, the terms “rubber” and “elastomer” are used synonymously and interchangeably, although “rubber” to some implies “natural rubber”. Elastomeric materials are used for insulation and sheaths. They are applied mainly where the product has to be particularly flexible. A wide range of elastomers are nowadays available to the cable industry. This makes possible the manufacture of compounds with specific properties, such as abrasion and oil resistance, 23

Power Cables & Wires Technical Manual weather and heat resistance, and flame resistance, combined with good electrical and mechanical characteristics. The classical elastomeric material, natural rubber (NR), was the first insulation to be used in the manufacture of electric cable. Its use as an insulation has been declining in recent years. Rubber gave way to other insulating materials like impregnated paper, PVC, XLPE, etc. Rubber, though, is still considered the preferred insulation for flexible cables and cables where very small bending diameter is desired. Rubbers for cable insulation and sheath, whether natural or synthetic, are normally crosslinked. In place of rubber, synthetic elastomers produced by the copolymerization of ethylene and propylene, are constantly finding new areas of application in cable engineering. These copolymers are generally known as Ethylene-propylene rubber (EPR). Because of its superior performance, with suitability for continuous operation at 90°C, EPR has gradually displaced butyl rubber for insulation and is now being considered as over sheath material for cable. Polychloroprene (PCP), otherwise known as neoprene, was the first commercial synthetic rubber. It has rarely been used by itself for insulation but is often used blended with natural rubber. Its major use is as a very tough flexible sheathing material. Polychloroprene compounds have good abrasion and tear resistance together with good resistance to swelling and to chemical attack by a wide range of natural oils and aliphatic hydrocarbons. They do not normally support combustion Chlorosulphonated polyethylene rubber (CSP, CSM) have superior electrical properties to compounds based on PCP and are particularly advantageous for insulation and sheathing which is required to be oil resistant. CSP also has good resistance to ozone and weathering. When blended with EVA or EPR and filled with a suitable carbon black, CSP compounds provide a strippable dielectric screening material for XLPE and EPR cables in the 1030kV range. 24

Power Cables & Wires Technical Manual Acrylonitrile-butadiene rubber (NBR/PVC blends) is the product of the co-polymerization of acrylonitrile with butadiene. This range of polymers is characterized by good oil resistance. The addition of PVC improves resistance to ozone, weathering and abrasion. By suitable choice of plasticizers, improved processability and flame retardance are also obtained. These materials are used solely for sheathing. Fluorocarbon rubbers find application for sheathing where very good resistance to oils is required at high temperatures. The best known material is a copolymer of vinylidene fluoride and hexafluoropropylene (Viton). Ethylene-acrylic elastomers (EMA) are heat- and oil-resistant non-halogen synthetic rubbers which can be compounded to resist ignition in the presence of flame and have low smoke generation when burned. They are suitable for service temperatures of 40-170°C. Silicone rubber is a material made from silicon and oxygen noted for high heat resistance. This is very soft thermoset insulation extremely flexible and fire resistant. It has excellent electrical properties plus ozone and resistance, low moisture absorption, weather resistance, and radiation resistance. It typically has low mechanical strength and poor scratch resistance. Table 8 shows the properties of thermoset insulation and jacket materials

25


SYNTHETIC RUBBER

POLY BUTADIENE

NEOPRENE

HYPALON CHLOROSULFONATED POLYETHYLENE (CSPE)

NITRILE//POLYCHLORIDE (NBR/PVC)

ETHYLENE PROPYLENE RUBBER (EPR)

CROSS-LINKED POLYETHYLENE (XLPE)

CHLORINATED POLYETHYLENE (CPE)

F

F

G

G

G

E

F

E

E

E

E

E

F-G

F

F

F

G

E

G

G

E

G

E

O

Oxidation Resistance Heat Resistance Oil Resistance

SILICONE RUBBER

NATURAL RUBBER

OR

STYRENE BUTADIENE RUBBER (SBR)

INSULATION JACKET MATERIAL

NITRILE OR RUBBER BUTADIENE NITRILE (NBR)

Table 8: Properties of Thermoset Insulation and Jacket Materials

P

P

P

P

G

G

G-E

G

P

G

G-E

F-G

F-G

G

E

E

F-G

F

F

F

G-E

O

F

O

F

F

F

F

G

E

F-G

G

E

G

E

O

P

P

P

P

G

E

P

G

E

G

G-E

O

Abrasion Resistance

G-E

E

E

E

G-E

G

G-E

E

G

F-G

G-E

P

Electrical Properties

E

E

E

E

P

G

P

F

E

E

F-G

O

Flame Resistance

P

P

P

P

G

G

P

G

P

P

G

O

F-G

F-G

F-G

P

F-G

E

F-G

P

G

E

G

E

Water Resistance

G-E

G-E

E

E

E

E

G-E

E

G-E

G-E

G-E

G-E

Acid Resistance

F-G

F-G

F-G

F-G

G

E

G

G

G-E

G-E

E

F-G

Alkali Resistance

F-G

F-G

F-G

F-G

G

E

F-G

G

G-E

G-E

E

F-G

Gasoline, Kerosene, Etc. (Aliphatic Hydrocarbons) Resistance

P

P

P

P

G

F

E

G-E

P

F

F

P-F

Benzol, Toluol, Etc. (Aromatic Hydrocarbons) Resistance

P

P

P

P

P-F

F

G

G

F

F

F

P

Degreaser Solvents (Halogenated Hydrocarbons) Resistance

P

P

P

P

P

P-F

P

G

P

F

P

P-G

Alcohol Resistance

F

G

G

F-G

F

G

E

G

P

E

G-E

G

Low Temp. Flexibility Weather, Resistance

Sun

Ozone Resistance

Nuclear Resistance

P = Poor

Radiation

F = Fair

G = Good

E = Excellent

26

O = Outstanding

Power Cables & Wires Technical Manual 6.2 Plastics Plastics may be further divided into thermoplastics and thermosets. A thermoplastic is a material in which the molecules are held together by physical rather than chemical bonds. This means that once the material is above its melting point it can flow. The process is reversible and upon cooling the material hardens. The molecules in a thermoset are held together by chemical bonds which are not easily broken. This means that on heating the polymer does not soften sufficiently to be reshaped. Typical examples are crosslinked polyethylene (XLPE) and elastomers. Unlike thermoplastics, thermosets are insoluble and infusible, i.e. it will not fuse together. Many thermoplastics may be converted to thermosets by appropriate treatment to induce “crosslinking”, e.g. by the addition of a suitable chemical crosslinking agent or by irradiation. 6.2.1 Thermoplastics Thermoplastics are the most popular insulating materials for low voltage wires and cables due to lower in cost and lighter weight. Some of the most popularly used are discuss below. Polyvinyl Chloride (PVC) Polyvinyl Chloride, also called vinyl, is a thermoplastic material introduced in 1932. Since then, PVC has become the standard insulation used on wires and cables rated at 1000 volts or less. Vinyl compounds are mechanical mixtures of PVC resin, plasticizers, fillers, stabilizers, and modifiers. The quantity and type of each ingredient determines the final properties of the compound. PVC compounds can be formatted to provide a broad range of properties from the standpoint of electrical, physical and chemical characteristics. However, in achieving superiority in one property, the other properties are usually compromised. The goal, therefore, is to optimize the critical property or properties without allowing secondary properties to fall below acceptable levels. 27


PVC has a high dielectric strength and good insulation resistance. It is inherently tough and resistant to flame, moisture and abrasion. Resistance to ozone, acids, alkalis, alcohols, and most solvents are also adequate. PVC compounds can be made resistant to oils and gasoline. Its temperature ratings range from 60°C to 105°C based on basic formulation. Disadvantage of PVC include a relatively high dielectric constant and dissipation factor. Plasticizer loss through evaporation or leeching eventually may cause embrittlement and cracking. PVC compounds significantly stiffen as temperatures decline, and are not generally recommended for uses which require flexing below -10°C. However, special formulations have been developed which will allow flexing to up to -40°C. Polyethylene Polyethylene is a long chain hydrocarbon thermoplastic material which is produced by the polymerization of ethylene gas under high or low pressure. PE is popular because of its relatively low price, processability, resistance to chemicals and moisture, electrical properties, and low temperature flexibility. PE is produced in low, linear low, medium, and high densities. As the density increases, so does the hardness, yield strength, stiffness, heat, and chemical resistance. PE’s electrical properties are excellent. Typical values for a natural, unfilled insulation compound include a volume resistivity of greater than 1016 ohm-cm, a dielectric constant of 2.3, a dissipation factor of 0.0002, and a water absorption of less than 0.1%. However, if PE cables are exposed to sunlight, carbon black or a suitable inhibitor is added to screen out ultraviolet (UV) radiation. UV radiation can degrade both the physical and electrical properties of the insulation. A disadvantage of PE is that, like most plastics, it is susceptible to degradation from treeing when it is subjected, to high electrical stress. Treeing is a phenomenon occurring within the cable, when subjected to medium to high voltages, wherein the 28

Power Cables & Wires Technical Manual breakdown of the insulation due to ionization occurs through the formation of carbonaceous “fronds” on the insulation due to the presence of water or voids during the extrusion of the insulation material at cable construction. The carbonaceous paths start at an almost imperceptible carbon core, generally at the conductor surface, and gradually spread outwards through the insulation, increasing in width and complexity as progression takes place. Corona discharges and treeing may lead to premature cable failure. Polypropylene Polypropylene is a thermoplastic insulating compound with characteristics similar to high density polyethylene with improved heat resistance, tensile strength, and abrasion resistance. Polypropylene also has a lower specific gravity and lower dielectric constant than polyethylene. Polypropylene has good impact strength, low moisture absorption, excellent chemical resistance, high creepage resistance, and is useful in high frequency applications. It retains these excellent properties in cellular constructions. Typically, it is harder than polyethylene. This makes it suitable for thin wall insulations. Polyurethane Polyurethane is a broad class of polymers noted for good abrasion and solvent resistance which can be in solid or cellular form. This thermoplastic material is used primarily as a cable jacket material. It has excellent oxidation, oil, and ozone resistance. Some formulations also have good flame resistance. It is a hard material with excellent abrasion resistance. It has outstanding "memory" properties, making it an ideal jacket material for retractile cords. Teflon Teflon is an extremely reliable high temperature, low voltage insulation often chosen for its non-aging characteristics, thin wall insulating capability, resistance to chemicals and abrasion resistance. Also, important is its low dielectric constant and low 29

Power Cables & Wires Technical Manual power factor. There are two (2) types-Tetrafluorethylene TFE, and Fluorinatedethylenepropylene FEP. Teflon is not damaged by normal soldering operations. It is not suitable when subjected to nuclear radiation and does not have good high voltage characteristics.TFE insulation in tape form (often fused) is widely used and can be provided in very long lengths. Type FEP can be extruded in long, continuous lengths and is readily color coded for use in control and instrumentation cables. Tefzel Tefzel ETFE is a melt processible fluorocarbon thermoplastic combining many of the desirable properties of Teflon and Kynar rated at 150°C. Mechanically it is tough with excellent flex life, impact, cut-through, abrasion and weather resistant. Electrically it is an excellent low loss dielectric and has outstanding electrical properties. It is inert to most solvents and chemicals and is hydrolytically stable. Like irradiated polyethylene, it has excellent resistance to high-energy radiation. Table 9 shows the properties of thermoplastic insulation and jacket materials.

30


POLYVINYL CHLORIDE (PVC)

LOW-DENSITY POLYTHYLENE

CELLULAR POLYTHYLENE

HIGH-DENSITY POLYTHYLENE

POLYPROPYLENE

CELLULAR POLYPROPYLENE

POLYUTETHANE

NYLON

CPE

TEFLON (FEP)

TEFLON (TPE)

TEFZEL (ETFE)

Table 9: Properties of Thermoplastic Insulation and Jacket Materials

E

E

E

E

E

E

E

E

E

O

O

E

G-E

G

G

E

E

E

G

E

E

O

O

E

F

G-E

G

G-E

F

F

E

E

E

O

E-O

E

P-G

E

E

E

P

P

G

G

E

O

O

E

G-E

E

E

E

E

E

G

E

E

O

O

E

E

E

E

E

E

E

E

E

E

E

O

E

Abrasion Resistance

F-G

G

F

E

F-G

F-G

O

E

E-O

E

O

E

Electrical Properties

F-G

E

E

E

E

E

P

P

E

E

E

E

Flame Resistance

E

P

P

P

P

P

P

P

E

O

E

G

Nuclear Radiation Resistance

F

G-E

G

G-E

F

F

G

F-G

O

P-G

P

E

Water Resistance

F-G

E

E

E

E

E

P-G

P-F

O

E

E

E

Acid Resistance

G-E

G-E

G-E

E

E

E

F

P-E

E

E

E

E

Alkali Resistance

G-E

G-E

G-E

E

E

E

F

E

E

E

E

E

Gasoline, Kerosene, Etc. (Aliphatic Hydrocarbons) Resistance

P

G-E

G

G-E

P-F

P

P-G

G

E

E

E

E

Benzol, Toluol, Etc. (Aromatic Hydrocarbons) Resistance

P-F

P

P

P

P-F

P

P-G

G

G-E

E

E

E

Degreaser Solvents (Halogenated Hydrocarbons) Resistance

P-F

G

G

G

P

P

P-G

G

E

E

E

E

Alcohol Resistance

G-E

E

E

E

E

E

P-G

P

E

E

E

E

INSULATION JACKET MATERIAL

OR

Oxidation Resistance Heat Resistance Oil Resistance Low Flexibility

Temp.

Weather, Resistance

Sun

Ozone Resistance

P = Poor

F = Fair

G = Good

E = Excellent

31

O = Outstanding

Power Cables & Wires Technical Manual 6.2.2 Thermosetting Most plastic insulations are thermoplastics, except for crosslinked polyethylene which is the predominant insulation for medium and high voltage cables. Other thermosetting insulation materials are elastomers. Crosslinked Polyethylene (XLPE) Crosslinked polyethylene is a thermoset material produced by compounding polyethylene or a copolymer of ethylene and vinyl acetate (EVA) with a crosslinking agent, usually an organic peroxide. The individual molecules of polyethylene join together during a curing process to form an interconnected network. The terms “cure” and “vulcanize” are often similarly used to designate crosslinking. While the use of peroxide as the crosslinking agent means that only low density polyethylene can operate at higher temperatures than cables produced with thermoplastic or non-crosslinked polyethylene. Crosslinking also significantly improves the physical properties of the polyethylene. Additives tend to reduce the electrical properties of the insulation. This is the reason that EVA copolymer is used only for low voltage applications. For medium voltage applications, crosslinked polyethylene fares well because the dielectric strength of the unfilled crosslinked polyethylene is about the same as that of thermoplastic polyethylene. Impulse strengths of 2700 V/mil are common. For low voltage applications, the addition of fillers, in particular, medium thermal carbon black, provides increases in tensile strength and hardness. It also provides the necessary ultraviolet protection for outdoor applications without the use of a jacket. The EVA copolymer is well suited to accepting up to a 30% loading of medium thermal carbon black. Between 2 and 3 percent of very small particle size furnace carbon black is incorporated into the polyethylene if sunlight resistance is required without significantly reducing the electrical properties. 32


XLPE insulated cables may be operated continuously at a conductor temperature of 90°C and intermittently at 130°C during emergency conditions. XLPE has good low temperature properties, shows increased resistance to corona when compared with thermoplastic polyethylene, and has good impact, abrasion, and environmental stress crack resistance. Recent technology has resulted in XLPE insulation compounds that are resistant to degradation from treeing. Two processes are available for imparting tree resistance to the compound. One involves additives and the other involves copolymer technology. Additives tend to reduce the electrical properties of the polyethylene insulation and one finds slightly lower values for dielectric strength and slightly higher dissipation factor when comparing the tree retardant insulations to the standard material. For general purpose low voltage cables, it is possible to incorporate up to 30% calcium carbonate into XLPE to reduce the cost. However, to maintain the best electrical properties, especially when immersed in water, the filled compound should not be used. In the Philippines, compounds incorporating approximately 30% thermal carbon black are used. These have the advantage of improved resistance to hot deformation and cut-through resistance. 6.3 Insulation Resistance In order that a reasonable factor of safety may be provided, the following insulation resistance is suggested as a guide, where the insulation is subjected to test: a) For circuits of 2.0 mm2 or 3.5 mm2 conductors – 500,000 ohms; b) For circuits of 5.5 mm2 or larger conductors, a resistance based upon the allowable ampacity of conductors as follows: 33


25 to 50 amperes, inclusive 51 to 100 amperes, inclusive 101 to 200 amperes, inclusive 201 to 400 amperes, inclusive 401 to 800 amperes, inclusive Over 800 amperes

250,000 ohms 100,000 ohms 50,000 ohms 25,000 ohms 12,000 ohms 5,000 ohms

The above listed values shall apply to installations with voltage of 600 V or less. For voltages above 600 V, the minimum insulation resistance shall be 1,000,000 ohms per thousand volts or a fraction thereof. The foregoing is to be determined with all fixtures, switches, receptacles, and wiring devices in place and connected. c)

Where climatic conditions are such that the wiring or equipment is exposed to excessive humidity, it may be necessary to modify the foregoing provisions.

6.4 Thermal Characteristics Selection of the right insulation materials depends on the expected operating temperature which the wire or cable will be subjected. The nominal operating temperature in °C of some the insulation materials are shown in Figure 2, below. -20 -55

PVC (Standard)

80

PVC (Premium)

105

-60

Polythylene

80

-40

Polypropylene

105

-40

XLPE

130

-60 -40

105

Hypalon (CSPE)

-40

105

EVA

-40

105

-65

CPE Silicone Rubber

200

-70 -100

EPR

150

Teflon

260 0

100

200

300

Figure 2: Nominal Temperature Range of Wire Insulations in °C 34


7. CABLE DESIGN AND CONSTRUCTION An insulated cable appears to be a relatively simple electrical device but, in fact, it can be considered an electrical system with many components. To understand it, let us examine its components and basics of operation. For simplicity, the following discussion shall be confined to a single conductor cable. However, these fundamentals also apply to multipleconductor cables. The basic components of an insulated cable are the following: a) Conductor – materials that transmits electrical energy b) Shielding – also referred to as screening, are used for medium to high voltage cables. Basically, the use of this stress control layers is to achieve a symmetrical dielectric fields within the cable structure. For some voltage levels, shielding may be applied over the conductor. At higher voltage levels, it is applied over the conductor and the insulation. This results in the confining of all the voltage gradients to within the cable structure if the shield over the insulation is essentially at ground potential. c) Primary Insulation or Dielectric – prevents leakage of current from the conductor to the surroundings. It protects life and prevents damage resulting from electrical discharge. It also physically protects the conductor. d) Jacket – also called sheaths, serve several purposes such as they provide mechanical, thermal, chemical, and environmental protection to the insulated conductors they enclosed, act as electrical insulation when used over shields or armor, ease installation and routing concerns by enclosing multiple insulated conductors. They may also protect the characteristics of the underlying insulation. For example, a thin nylon jacket over PVC enhances the abrasion and fluid resistance of a 600V cable. Sheathing may also include various forms of metallic armoring, tapes, or wires to enhance the physical properties of the cable and to provide a built-in protective electrically grounded conduit for the insulated conductors. Commonly used jacketing materials include extrusions of PE, PVC and Nylon. PVC, Nylon and PE 35

Power Cables & Wires Technical Manual are applied using thermoplastic extrusion lines which heat the material to the melting point and form it over the core. The material is then cooled, usually in a water trough, and wound onto a reel. Some heat is used to soften the material so that it can be formed around the core. It is then necessary to crosslink the material to obtain its full properties. Depending on the customer requirement and/or the application, a cable may be composed of a couple of the above-stated components or all of it. For special cases, additional sheathing or armoring may be required. An illustration of the construction and components of a medium voltage power cable is shown below.

Figure 3: Construction of a Medium Voltage Power Cable

8. LOW VOLTAGE WIRES AND CABLES Classification of voltage level seems to be arbitrary in most cases since many standard governing bodies in the world do not agree as to the divisions in the voltage level. IEC define low voltage as those 1000 volts and below while ICEA define low voltage to be 2000 volts and below. NEC and IEEE define low voltage as 600 volts and below. Primarily all low voltage wires and cables are insulated except those used as neutral or grounding wire. With reference to their cable construction, they are non-shielded cable. 36

Power Cables & Wires Technical Manual There are two basic components in a non-shielded cable. They are the conductor and the electrical insulation, sometimes referred to as the dielectric. A third component used in some cable designs is an outer jacket. The figure below shows the construction of a low-voltage nonshielded cable.

Figure 4: Low-Voltage Non-Shielded Cable Construction

Conductor The conductor material can be copper or aluminum with either a solid or stranded. The primary reason for the use of stranded conductors is improved flexibility. The stranded conductors can be compressed or compacted to achieve desired flexibility, diameter, and load current density. For the conductor size, there are diameter differences between solid and the various types of stranded conductors. This is an important consideration in the selection of connectors and in the methods of splicing and terminating. Electrical Insulation or Dielectric The electrical insulation must provide adequate physical and electrical protection between the energized conductor and the nearest electrical ground to prevent electrical breakdowns. For low voltage cables, 600 volts and below, the insulation thickness required to provide the necessary physical protection against damage is more than adequate to provide the necessary dielectric strength. 37


Another consideration in the design and application of cables is the dielectric field. In all electrical cables, irrespective of their voltage ratings, there is a dielectric field present when the conductor is energized. This dielectric field is typically represented by electrostatic flux lines and equipotential lines between the conductor and electrical ground. When a conductor is energized there are electrostatic lines of flux created within the dielectric. The density of these flux lines is dependent upon the magnitude of the potential difference between the conductor and electrical ground. The distance between the equipotential lines represents a voltage differential in the insulation. For a given voltage differential, these lines are closer together nearer the conductor.

Electrostatic Flux Lines

Equipotential Lines

Figure 5: Electrical Field of a Non-Shielded Cable Above figure represents the electrical field of a non-shielded cable’s contact with a ground plane. It does not take into account the difference in the dielectric constants of the insulation and the surrounding air. Observe that the electrostatic flux lines are crowded in the insulation closest to the ground. Also, the equipotential lines are eccentric in their relationship to the conductor and the cable dielectric surface. This distortion of the fields is acceptable if the dielectric strength of the cable insulation is adequate to resist the concentration of the dielectric stresses. Low voltage non-shielded cables are usually designed to meet this requirement. Jacket/Sheaths For special applications, a jacket is applied over the insulation. There are several materials available for use as jackets to provide the necessary chemical, physical, or thermal protection required by the application. 38

Power Cables & Wires Technical Manual Low voltage wires and cables are primarily divided into two major groups, the building wires and secondary and service drop wires. 8.1 Building Wires Building wires comprises the largest group of low voltage wires and cables which is primarily used in all residential, commercial and industrial buildings. In the Philippines, the most common types of these building wires are the following: 8.1.1 Building Wires Types and Application TW (Thermoplastic Moisture-Resistant) The TW conductors are solid or stranded annealed (soft) copper, insulated with a moisture resistant and flame retardant polyvinyl compound (PVC). TW wire is used in interior wiring at circuit voltages up to 600 volts. Maximum operating temperature is 60°C in dry or wet application. Type TW building wire is used in residential, commercial and industrial buildings for generalpurpose lighting, appliance, power, control and relay panel applications. It is used for low ampacity rated circuits. This type of wire may be installed in conduits, ducts or raceways. Type TW wire is also suitable for installations in ambient temperatures down to -10°C. THW (Thermoplastic Heat and Moisture Resistant) The THW conductors are solid or stranded annealed (soft) copper, insulated with a tough heat and moisture resistant, and flame retardant polyvinyl compound (PVC). It is used in interior wiring at circuit voltages up to 600 volts. Maximum operating temperature is 75°C in dry or wet application. It can be used for general-purpose lighting, appliance, power, control and relay panel applications. It is also applicable as machine tool wire and appliance wiring material. It is used for medium ampacity rated circuits. This type of wire may be installed in conduits, ducts or raceways. 39

Power Cables & Wires Technical Manual THHN/THWN (Thermoplastic Heat and Moisture Resistant Wire with Nylon Jacket) The THHN/THWN conductors are solid or stranded annealed (soft) copper, insulated with a tough heat and moisture resistant, and flame retardant polyvinyl compound (PVC) with oil, chemical, and abrasion resistant nylon (polyamide) jacket. It is used in interior wiring at circuit voltages up to 600 volts. Maximum operating temperature is 90°C for dry applications (THHN) and 75°C for wet applications (THWN). It can be used for general-purpose lighting, power, control and relay panel applications. It is also applicable for machine tool wire and appliance wiring material. It is used for high ampacity rated circuits. This type of wire may be installed in conduits, ducts or raceways. The other types of conductor applications and insulations are shown in Annex B. 8.1.2 Building Wires Sizes and Ampacity Size and ampacity of building wires are given in Tables 10 and 11, with reference to the Philippines Electrical Code based on an ambient temperature of 30°C. Use appropriate correction factor specified in the Philippine Electrical Code for ambient temperature other than 30°C.

40

Power Cables & Wires Technical Manual Table 10: Allowable Ampacities of Single-Insulated Conductors Rated 0 Through 2 000 Volts in Free Air, Based on Ambient Air Temperature of 30°C Temperature Rating of Conductor 75°C 90°C 60°C 75°C 90°C Types Types TBS, SA, TBS, SA, SIS, FEP, SIS, RHH, Types FEPB, RHW-2, RHW, MI, Types THHN, THHW, RHH, RHW, THHW, THW, RHW-2, THHW, THW-2, Conductor Types THWN, THHN, Types THW, THWN-2, TW, XHHW, THHW, TW, THWN, USE-2, Size UF ZW mm2 THW-2, UF XHHW XHH, (mm dia.) COPPER ALUMINUM 2 (1.6) 25 30 35 3.5 (2) 30 35 40 25 30 35 5.5 (2.6) 40 50 55 35 40 40 8 (3.2) 55 65 75 45 50 55 14 80 95 105 65 80 85 22 105 130 140 85 105 115 30 130 160 170 95 115 130 38 155 185 195 115 135 155 50 180 220 235 135 165 185 60 205 250 260 155 185 210 80 250 300 320 185 225 255 100 290 355 370 220 265 295 125 335 400 420 260 310 350 150 375 440 475 295 355 400 175 410 495 560 325 390 440 200 440 540 570 345 410 465 250 505 620 655 405 485 545 325 600 720 770 475 560 640 375 645 775 875 510 615 690 400 675 810 875 530 640 725 500 770 930 995 620 745 835 60°C

41

Power Cables & Wires Technical Manual Table 11: Allowable Ampacities of Insulated Conductors Rated 0 Through 2 000 Volts, 60°C Through 90°C. Not More Than Three Current-Carrying Conductors in Raceway, Cable, or Earth (Directly Buried), Based on Ambient Temperature of 30°C Temperature Rating of Conductor 60°C

Conductor Size mm2 (mm dia.)

75°C

90°C

60°C

75°C

90°C

Types TBS, SA, SIS, FEP, Types TBS, FEPB, MI, SA, SIS, RHH, RHWRHH, RHW2, THHN, 2, THHN, THHW, THHW, THW-2, THW-2, Types RHW, THWN-2, Types RHW, THWN-2, THHW, USE-2, XHH, THHW, USE-2, XHH, THW, XHHW, THW, XHHW, Types THWN, XHHW-2, Types THWN, XHHW-2, TW, UF XHHW, ZW ZW-2 TW, UF XHHW ZW-2 COPPER

ALUMINUM

2 (1.6) 3.5 (2) 5.5 (2.6) 8 (3.2)

20 25 30 40

20 25 35 50

25 30 40 55

20 25 30

20 30 40

25 35 45

14 22 30 38

55 70 90 100

65 85 110 125

70 90 115 130

40 55 65 75

50 65 80 90

65 80 90 105

50 60 80 100

120 135 160 180

145 160 195 220

150 170 205 225

95 100 120 140

110 120 145 170

125 135 165 190

125 150 175 200 250

210 240 260 280 315

255 280 305 330 375

265 295 345 355 400

165 185 205 220 255

200 225 245 265 305

225 250 275 .300 345

325 375 400 500

370 395 405 445

435 470 485 540

470 530 515 580

305 315 335 370

365 380 405 440

410 430 460 495

Apply appropriate adjustment factors if more than three (3) current carrying conductors in a raceway or cable with reference to the Philippine Electrical Code.

42


8.1.3 Resistances and Reactances Resistances and reactances of copper wires in magnetic and nonmagnetic conduits are given by Table 12, below: Table 12: Copper Conductor Resistance and Reactance Data Line-toneutral, mΩ/100 meter Three-Single Conductor Cables In Magnetic Duct Not In Magnetic Duct Conductor Size mm2 Resistance Reactance Resistance Reactance (mm dia.) "R" "X" "R" "X" Solid 2 (1.6) 846.24 24.63 846.24 19.48 3.5 (2) 528.08 22.83 528.08 18.07 5.5 (2.6) 331.28 22.11 331.28 17.52 8 (3.2) 216.15 19.88 216.15 15.91 Stranded 8 222.71 19.45 222.71 15.55 14 140.06 18.60 140.06 14.89 22 88.23 17.38 88.23 13.91 30 55.76 16.33 55.43 13.05 38 44.28 16.53 43.95 13.22 50 35.42 16.24 35.10 12.99 60 28.21 15.84 27.88 12.66 80 22.63 15.32 21.98 12.23 100 17.81 14.86 17.48 11.87 125 15.48 15.25 15.06 12.20 150 12.96 14.83 12.46 11.84 200 10.00 14.46 9.54 11.58 250 8.20 14.17 7.71 11.35 325 7.08 14.14 6.53 11.28 400 5.94 13.94 5.35 11.15 500 5.02 13.74 4.43 10.99 Note: Typical values, use exact values if available.

43


8.2 Secondary and Service Cables These cables are used by Distribution Utilities in low voltage power distribution. Both cables have the same construction; the difference is in the application. Secondary cables are those that are connected to the distribution transformer and traverses from pole to pole while service drop cables are those that connect the customer’s service entrance wires to the secondary cable or distribution transformer. 8.2.1 Overhead secondary and service cables In the Philippines, majority of the distribution system are overhead construction. Most overhead secondary and service cables are multiplex cables with sizes that are typically based in AWG. Cables are insulated by either polyethylene (PE) or crosslinked polyethylene (XLPE) material. Basically, these cables are classified based on the number of conductors twisted together (e.g. duplex, triplex, and quadruplex cables). 8.2.2 Underground secondary and service cables Underground secondary and service cables are conductors installed in conduit or directly buried in the earth and enter the building metering facilities, switch, or service equipment. Type USE service cables are similar in construction to the general power cables for direct burial in earth. Tables 13 & 14 show the characteristics of the different types of Multiplex Secondary and Services Copper and Aluminum Cables, respectively. While, Tables 15 & 16 show the characteristics of the types of Single Conductors for Underground Service for Copper and Aluminum, respectively.

44


Table 13. Copper Multiplex Secondary and Services Cables Phase Conductor Code Word

Sizes (# of wires)

Neutral

Insulation Thickness (mils)

Sizes (# of wires)

Rated Strength (lbs.)

Cable Weight per 1000 ft (lbs)

529

Ampacity PE

XLPE

95

70

85

DUPLEX Theta

8 (7)

45

10 (1)

Kappa

8 (7)

45

8 (7)

777

114

70

85

Sigma

6 (7)

45

6 (7)

1228

177

90

110

TRIPLEX Pica

8 (7)

45

10 (1)

529

158

70

85

Garamond

8 (7)

45

8 (7)

777

177

70

85

Gothic

6 (7)

45

6 (7)

1228

273

90

110

Casion

4 (7)

45

4 (7)

1938

425

115

145

Primer

2 (7)

45

4 (7)

1938

588

155

195

Century

2 (7)

45

2 (7)

3050

664

155

195

Corinthian

1/0 (19)

60

1/0 (7)

4752

1055

205

265

Doric

2/0 (19)

60

2/0 (7)

5926

1319

235

300

Tallahassee

6 (7)

45

6 (7)

1228

369

75

95

Richmond

4 (7)

45

4 (7)

1938

573

100

125

Seattle

2 (7)

45

2 (7)

3050

893

135

170

Nashville

1/0 (19)

60

1/0 (7)

4752

1420

180

230

Lincoln

2/0 (19)

60

2/0 (7)

5926

1773

205

265

Raleigh

3/0 (19)

60

3/0 (7)

7366

2220

235

305

Denver

4/0 (19)

60

4/0 (7)

9154

2781

270

350

QUADRUPLEX

Ampacity figures for black insulation only. Based on conductor temperature of 75°C for polyethylene insulated conductors, 90°C for XLPE insulated conductors, ambient temperature of 40°C; 2 ft./sec. wind in sun. Source: Southwire

45


Table 14: Aluminum Multiplex Cables with ACSR Neutral Messenger Phase Conductor Code Word

Sizes (# of wires)

Neutral

Insulation Thickness (mils)

Sizes (Stranding)

Rated Strength (lbs.)

Cable Weight per 1000 ft (lbs)

Ampacity PE

XLPE

DUPLEX Shepherd

6 (7)

45

6 (6/1)

1190

75

70

85

Terrier

4 (7)

45

4 (6/1)

1860

115

90

115

Chow

2 (7)

45

2 (6/1)

2850

176

120

150

Bull

1/0 (9)

60

1/0 (6/1)

4380

280

160

205

Voluta

6 (7)

45

6 (6/1)

1190

114

70

85

Periwinkle

4 (7)

45

4 (6/1)

1860

172

90

115

TRIPLEX

Conch

2 (7)

45

2 (6/1)

2850

262

120

150

Neritina

1/0 (7)

60

1/0 (6/1)

4380

420

160

205

Cenia

1/0 (9)

60

1/0 (6/1)

4380

414

160

205

Runcina

2/0 (7)

60

2/0 (6/1)

5310

520

185

235

Triton

2/0 (11)

60

2/0 (6/1)

5310

512

185

235

Mursia

3/0 (17)

60

3/0 (6/1)

6620

635

215

275

Zuzara

4/0 (18)

60

8350

789

245

315

Limpet

336.4 (19)

60

8680

1167

325

420

Hackney

4 (7)

45

4 (6/1)

1860

229

80

100

Palomino

2 (7)

45

2 (6/1)

2850

347

105

135

Costena

1/0 (9)

60

1/0 (6/1)

4380

549

140

180

Grullo

2/0 (11)

60

2/0 (6/1)

5310

677

160

205

Suffolk

3/0 (17)

60

3/0 (6/1)

6620

837

185

235

Appaloosa

4/0 (18)

60

8350

1038

210

275

Bronco

336.4 (19)

60

4/0 (6/1) 336.4 (18/1)

8680

1568

280

370

4/0 (6/1) 336.4 (18/1) QUADRUPLEX

Conductor temperature of 90°C for XLPE, 75°C for PE; ambient temperature of 40°C; emissivity 0.9; 2 ft./sec. wind in sun. Source: Southwire

46


Table 15: Single Copper Conductors for Underground Service

Size (AWG or kcmil)

Number of Strands

Composite InsulationThickness (mils)

Composite InsulationThickness (mm)

Approx. O.D. (Inches)

Approx. O.D. (mm)

Approx. Net Weight per 1000 ft. (lbs)

14

1

45

1.14

0.16

4.06

14

7

45

1.14

0.17

12

1

45

1.14

12

7

45

10

1

45

10

7

8

Ampacity

90°C

75°C

23

15

15

4.57

25

15

15

0.18

4.57

32

20

20

1.14

0.19

4.83

34

20

20

1.14

0.2

5.08

46

30

30

45

1.14

0.21

5.33

48

30

30

7

60

1.52

0.27

6.86

77

55

50

6

7

75

1.91

0.34

8.64

123

75

65

4

7

75

1.91

0.38

9.75

176

95

85

2

7

75

1.91

0.43

11

257

130

115

1

19

100

2.54

0.52

13.16

349

150

130

1/0

19

100

2.54

0.56

14.1

413

170

150

2/0

19

100

2.54

0.6

15.14

509

195

175

3/0

19

100

2.54

0.64

16.33

622

225

200

4/0

19

100

2.54

0.7

17.68

766

260

230

250

37

130

3.3

0.81

20.57

944

290

255

350

37

130

3.3

0.91

23.04

1273

350

310

500

37

130

3.3

1.03

26.19

1764

430

380

750

61

145

3.68

1.28

32.51

2625

535

475

1000

61

145

3.68

1.44

36.58

3443

615

545

Source: Okonite

47


Table 16: Single Aluminum Conductor for Underground Service Impedance (ohm/1000ft) *

Code Word

Size (# of Wires)

Conductor Diameter (inch)

Insulation Thickness (inch)

Insulation Diameter (inch)

Total Weight (lb/1000 ft)

AC Resistance

@ 75°C

@ 90°C

Inductive Reactance @60Hz

CORNELL/XLP

8 (7)

0.141

0.06

0.26

34

1.28

1.35

0.047

PRINCETON/XLP

6 (7)

0.178

0.06

0.3

47

0.807

0.847

0.0447

MERCER/XLP

4 (7)

0.225

0.06

0.35

67

0.508

0.533

0.0426

CLEMSON/XLP

2 (7)

0.283

0.06

0.41

97

0.319

0.335

0.0409

KENYON/XLP

1 (19)

0.322

0.08

0.49

128

0.253

0.266

0.0411

HARVARD/XLP

1/0 (19)

0.362

0.08

0.52

154

0.201

0.211

0.0402

YALE/XLP

2/0 (19)

0.406

0.08

0.57

186

0.159

0.167

0.0394

TUFTS/XLP

3/0 (19)

0.456

0.08

0.62

225

0.126

0.133

0.0387

BELOIT/XLP

4/0 (19)

0.512

0.08

0.68

274

0.1

0.105

0.038

HOFSTRA/XLP

250 (37)

0.558

0.095

0.75

329

0.085

0.0892

0.0382

GONZAGA/XLP

300 (37)

0.611

0.095

0.81

385

0.071

0.0744

0.0377

RUTGERS/XLP

350 (37)

0.66

0.095

0.85

439

0.0609

0.0639

0.0373

DARTMOUTH/XLP

400 (37)

0.706

0.095

0.9

493

0.0534

0.056

0.0369

BROWN/XLP

450 (37)

0.749

0.095

0.94

547

0.0476

0.0499

0.0366

EMORY/XLP

500 (37)

0.789

0.095

0.98

601

0.0429

0.045

0.0364

DUKE/XLP

600 (61)

0.866

0.11

1.09

725

0.036

0.0377

0.0365

FURMAN/XLP

700 (61)

0.935

0.11

1.16

830

0.0311

0.0325

0.0362

SEWANEE/XLP

750 (61)

0.968

0.11

1.19

883

0.0291

0.0305

0.036

FORDHAM/XLP

1000 (61)

1.118

0.11

1.34

1144

0.0223

0.0233

0.0354

* At random (calculated as 1.5 x cable OD) spacing between conductors. Source: Nexans

48

Power Cables & Wires Technical Manual 9. MEDIUM AND HIGH VOLTAGE WIRES AND CABLES There is no consensus among standard governing bodies like (i.e., IEC, ANSI, IEEE, UL, NEC and others) concerning the classification of voltage level. Thus, for clarity of this manual we will utilize IEEE voltage level classifications wherein 601 V to 69,000 V is medium voltage and 69,001 V to 230,000 V is high voltage. Furthermore, conductors are also classified according to their degree of insulation covering (i.e. bare, covered, and insulated). Basically, construction of the wires and cables is the same or similar for medium and high voltage applications. 9.1 Bare Conductors Bare conductors are those without covering and primarily used for overhead power transmission and distribution application. Insulating medium is air wherein the conductors are spaced from each other and any grounded object based on the system voltage. Insulators (e.g porcelain, glass, and polymers) are used to support the conductors and insulate these from the supporting structure such as tower or pole. Copper and aluminum conductors are commonly used for this application. However, there are instances where economics dictate the use of conductors with low conductivity such as galvanized steel, copper-clad steel (Copperweld) or aluminum-clad steel (Alumoweld) in the distribution system. In such cases, the conductor losses are lower than the cost of recovering the investment in the distribution line if copper or aluminum conductor is used. In this field of application, the most dominant conductor used by the industry is the aluminum conductor steel reinforced (ACSR). The succeeding tables (i.e., 17 to 19) show the physical and electrical data for copper and aluminum conductors.

49

Power Cables & Wires Technical Manual Table 17: Bare Stranded Copper Wires Physical and Electrical Data Hard-Drawn Size Weight Stran- Stranding Dia. (AWG or Per 1000 ding Class (mils) kcmil) ft. (Ibs.)

8

7

6

7

4

7

3

7

2 1

B

Medium-Hard Drawn

Soft-Drawn (Annealed)

Allowable Rated DC Resistance Rated DC Resistance Rated DC Resistance Ampacity Strength Ohms/1000 ft Strength Ohms/1000 ft Strength Ohms/1000 ft (lbs) @ 20°C (lbs) @ 20°C (lbs) @ 20°C

51

146

777

0.6663

610

0.6629

B

81

184

1228

A, B

128.9

232

1938

0.4191

959

0.4169

0.2636

1505

0.2622

A, B

162.5

260

2433

0.209

1885

0.2079

7

A, B

204.9

292

7

A

258.4

328

3050

0.166

2360

3801

0.1316

2955

1/0

7

A, AA

326.1

368

4752

0.1042

3705

1/0

19

B

2/0

7

A, AA

326.1

373

4752

0.1042

410.9

414

5926

0.08267

2/0

19

B

410.9

418

6690

3/0 4/0

7

A, AA

518.1

464

7

A, AA

653.3

522

4/0

19

B

653.3

250

19

A

250

37

B

300

19

350 500

499

0.6408

95

794

0.403

130

1320

0.2534

170

1670

0.201

200

0.165

2110

0.1578

230

0.1309

2552

0.1252

265

0.1037

3221

0.1002

310

3705

0.1037

3221

0.1002

310

4640

0.08224

4062

0.07949

355

0.08267

4765

0.08224

4024

0.07949

355

7366

0.06556

5812

0.06522

5118

0.06304

410

9154

0.05199

7278

0.05172

6459

0.04999

480

528

9617

0.05199

7479

0.05172

6453

0.04999

480

771.9

574

11360

0.044

8836

0.04378

7627

0.04231

530

771.9

575

11600

0.044

8952

0.04378

7940

0.04231

530

A

926.2

628

13510

0.03667

10530

0.03648

9160

0.03526

590

19

A

1080.6

679

15590

0.03143

12200

0.03127

10680

0.03022

650

37

A, B

1543.8

814

22510

0.022

17550

0.02189

15240

0.02116

810

600

37

A, AA

1852.5

891

27020

0.01834

21060

0.01825

18300

0.01763

910

750

61

A, B

2315.6

998

34090

0.01467

26510

0.01459

22890

0.0141

1040

1000

61

A, B

3087.5

1152

45030

0.011

35100

0.01094

30500

0.01058

1240

Ampacity based on 75°C conductor temperature; 25°C ambient temperature; 2 ft/sec wind in sun. Source: Southwire

50

Power Cables & Wires Technical Manual Table 18: Aluminum Conductor Steel Reinforced (ACSR) Physical Data Size (AWG or kcmil)

Diameter (inch)

Weight (lb/1000ft)

Steel Wire

Al Wire

Steel Core

Al

Steel

Total

Rated Strength (lbs)

Turkey

6

6/1

0.0661

0.0661

0.066

0.198

24.4

11.6

36

1190

Swan

4

6/1

0.0834

0.0834

0.083

0.25

39

18.4

57.4

1860

Swanate

4

7/1

0.1029

0.0772

0.103

0.257

39

28

67

2360

Sparrow

2

6/1

0.1052

0.1052

0.105

0.316

61.9

29.3

91.2

2850

Sparate

2

7/1

0.1299

0.0974

0.13

0.325

62.3

44.7

102

3640

Robin

1

6/1

0.1181

0.1181

0.118

0.355

78.1

36.9

115

3550

Raven

1/0

6/1

0.1327

0.1327

0.133

0.398

98.4

46.6

145

4380

Quail

2/0

6/1

0.1489

0.1489

0.149

0.447

124.2

58.8

183

5310

Pigeon

3/0

6/1

0.1672

0.1672

0.167

0.502

155.9

74.1

230

6620

Penguin

4/0

6/1

0.1878

0.1878

0.188

0.563

197.6

93.4

291

8350

Waxwing

266.8

18/1

0.1217

0.1217

0.122

0.609

249.8

39.2

289

6880

Partridge

266.8

26/7

0.0788

0.1013

0.236

0.642

250.4

115.6

366

11300

Merlin

336.4

18/1

0.1367

0.1367

0.137

0.684

315.5

49.5

365

8680

Linnet

336.4

26/7

0.0884

0.1137

0.265

0.72

316.5

145.5

462

14100

Oriole

336.4

30/7

0.1059

0.1059

0.318

0.741

317

209

526

17300

Chickadee

397.5

18/1

0.1486

0.1486

0.149

0.743

372.5

58.5

431

9940

Ibis

397.5

26/7

0.0961

0.1236

0.288

0.783

374.1

171.9

546

16300

Pelican

477

18/1

0.1628

0.1628

0.163

0.814

446.8

70.2

517

11800

Flicker

477

24/7

0.094

0.141

0.282

0.846

449.5

164.5

614

17200

Hawk

477

26/7

0.1053

0.1354

0.316

0.858

448.6

206.4

655

19500

Hen

477

30/7

0.1261

0.1261

0.378

0.883

449.7

296.3

746

23800

Osprey

556.5

18/1

0.1758

0.1758

0.176

0.879

521.1

81.9

603

13700

Parakeet

556.5

24/7

0.1015

0.1523

0.305

0.914

524.2

191.8

716

19800

Dove

556.5

26/7

0.1138

0.1463

0.341

0.927

523.9

241.1

765

22600

Rook

636

24/7

0.1085

0.1628

0.326

0.977

598.8

219.2

818

22000

Grosbeak

636

26/7

0.1216

0.1564

0.365

0.99

598.7

275.3

873

25200

Drake

795

26/7

0.136

0.1749

0.408

1.108

749

344

1093

31500

Tern

795

45/7

0.0886

0.1329

0.266

1.063

748.9

146.1

895

22100

Rail

954

45/7

0.0971

0.1456

0.291

1.165

899

176

1075

25900

Cardinal

954

54/7

0.1329

0.1329

0.399

1.96

899

329

1228

33800

Curlew

1033.5

54/7

0.1383

0.1383

0.415

1.245

973

356

1329

36600

Bluejay

1113

45/7

0.1049

0.1573

0.315

1.259

1049

205

1254

29800

Bittern

1272

45/7

0.1121

0.168

0.336

1.345

1198

234

1432

34100

Lapwing

1590

45/7

0.1253

0.188

0.376

1.504

1498

292

1790

42200

Bluebird

2156

84/19

0.0961

0.1602

0.481

1.762

2040

468

2508

60300

Code word

No. of Wires

Source: Nexans

51

Complete Conductor

Power Cables & Wires Technical Manual Table 19: Aluminum Conductor Steel Reinforced (ACSR) Electrical Data Resistance (ohm/kft)

Code word

Size (AWG or kcmil)

DC at 20°C

AC at 25°C

Turkey

6

0.642

Swan

4

0.403

Swanate

4

Sparrow

Reactance at 60 Hz** Inductive at 25°C (ohm/kft)

Inductive at 50°C (ohm/kft)

Inductive at 75°C (ohm/kft)

Ampacity* (A)

0.751

0.12

0.139

0.144

105

0.715

0.115

0.131

0.137

140

0.516

0.71

0.113

0.124

0.13

140

0.308

0.336

0.678

0.11

0.123

0.128

185

0.256

0.297

0.33

0.674

0.109

0.118

0.121

185

0.201

0.206

0.247

0.27

0.66

0.107

0.119

0.122

210

1/0

0.159

0.163

0.197

0.216

0.642

0.104

0.114

0.116

240

Quail

2/0

0.126

0.13

0.162

0.176

0.624

0.102

0.112

0.113

275

Pigeon

3/0

0.1

0.103

0.121

0.145

0.606

0.0992

0.108

0.109

315

Penguin

4/0

0.0795

0.0822

0.107

0.116

0.597

0.0964

0.105

0.105

365

Waxwing

266.8

0.0644

0.0657 0.0723 0.0788

0.576

0.0903

0.0903

0.0903

445

Partridge

266.8

0.0637

0.0652 0.0714 0.0778

0.565

0.0881

0.0881

0.0881

455

Merlin

336.4

0.051

0.0523 0.0574 0.0625

0.56

0.0826

0.0826

0.0826

515

Linnet

336.4

0.0506

0.0517 0.0568 0.0619

0.549

0.0854

0.0854

0.0854

530

Oriole

336.4

0.0502

0.0513 0.0563 0.0614

0.544

0.0843

0.0843

0.0843

530

Chickadee

397.5

0.0432

0.0443 0.0487 0.0528

0.544

0.0856

0.0856

0.0856

575

Ibis

397.5

0.0428

0.0438 0.0481 0.0525

0.539

0.0835

0.0835

0.0835

590

Pelican

477

0.036

0.0369 0.0405 0.0441

0.528

0.0835

0.0835

0.0835

640

Flicker

477

0.0358

0.0367 0.0403 0.0439

0.524

0.0818

0.0818

0.0818

670

Hawk

477

0.0357

0.0366 0.0402 0.0438

0.522

0.0814

0.0814

0.0814

660

Hen

477

0.0354

0.0362 0.0398 0.0434

0.517

0.0803

0.0803

0.0803

660

Osprey

556.5

0.0309

0.0318 0.0348 0.0379

0.518

0.0818

0.0818

0.0818

710

Parakeet

556.5

0.0307

0.0314 0.0347 0.0377

0.512

0.0801

0.0801

0.0801

720

Dove

556.5

0.0305

0.0314 0.0345 0.0375

0.51

0.0795

0.0795

0.0795

730

Rook

636

0.0268

0.0277 0.0303

0.033

0.502

0.0786

0.0786

0.0786

780

Grosbeak

636

0.0267

0.0275 0.0301 0.0328

0.499

0.078

0.078

0.078

790

Drake

795

0.0214

0.0222 0.0242 0.0263

0.482

0.0756

0.0756

0.0756

910

Tern

795

0.0216

0.0225 0.0246 0.0267

0.488

0.0769

0.0769

0.0769

890

Rail

954

0.018

0.0188 0.0206 0.0223

0.474

0.0748

0.0748

0.0748

970

Cardinal

954

0.0179

0.0186 0.0205 0.0222

0.47

0.0737

0.0737

0.0737

990

Curlew

1033.5

0.0165

0.0172 0.0189 0.0205

0.464

0.0729

0.0729

0.0729

1040

Bluejay

1113

0.0155

0.0163 0.0178 0.0193

0.461

0.0731

0.0731

0.0731

1070

Bittern

1272

0.0135

0.0144 0.0157

0.017

0.451

0.0716

0.0716

0.0716

1160

Lapwing

1590

0.0108

0.0117 0.0128 0.0138

0.434

0.0689

0.0689

0.0689

1340

Bluebird

2156

0.00801 0.00903 0.00977 0.0105

0.409

0.0652

0.0652

0.0652

1610

AC at 50°C

AC at 75°C

Capacitive (megohm-kft)

0.655

0.75

0.816

0.412

0.479

0.522

0.399

0.407

0.463

2

0.253

0.259

Sparate

2

0.251

Robin

1

Raven

* Ampacity is with sun and wind at 2 ft/s

** Reactance at 1 foot equivalent spacing

Source: Nexans

52

Power Cables & Wires Technical Manual 9.2 Covered Conductors Covered conductors are bare conductors with thin insulation covering used for overhead power distribution system. These are used for power distribution circuits that transverse along routes with heavy tree growth. The covering does not fully insulate the conductor but it is thick enough to reduce the chances of flashover whenever a tree branch falls between the conductors. Covered conductor is also commonly known as tree wire. Also, it helps minimize faults caused by animals and enable distribution utilities to utilize conductor configurations with tight spacing. Covered conductors are commonly used as a cost-effective method for increasing overhead line reliability. The conductor materials are typically copper or aluminum or other conductors designed to give a balance between strength and conductivity such as ACSR. Tree wire is commonly covered by insulating materials such as polyethylene, XLPE, or EPR. Insulation thickness typically ranges from 30 to 150 mils. Tree wires must always be treated as bare conductors. However, closer spacings are allowed for this type of conductor. While covered conductors help against trees, it has several setbacks compared to bare conductors. The covering may be susceptible to degradation due to ultraviolet radiation, tracking, and mechanical effects that cause cracking. Also, covered conductors are susceptible to burn-downs. Burn-down is when a conductor burns through or melts and falls to the ground. A covered conductor line can suffer burn-down due to lightning strikes, excessive tracking over time, vibration fatigue or tree branches falling on the line. The risk of burndown can be reduced by suitable lightning protection systems, reduction of electrical stresses, improved tree trimming, reduced carbon black content in the sheath material, and proper installation and tensioning. The additional covering adds cost to the conductor such that a covered conductor line would cost about at least 20% more than a bare conductor line. Covered conductors are heavier and have larger diameters so wind loading is higher than bare conductors. Also, a damage cover makes it susceptible to corrosion, primarily from water. 53

Power Cables & Wires Technical Manual If water penetrates the covering, it settles at the low points and causes corrosion since the covering prevents the trapped water from evaporating. Water enters the conductor at pinholes caused by lightning strikes, cover damage caused by abrasion, and at holes pierced by connectors. In contrast, rain simply washes over bare conductors and evaporation takes care of moisture. There will be a low charging current flowing along the covered conductor sheath since its surface is insulating but not fully insulated. This arises because the sheath forms an insulating layer between the high voltage conductor (metal) and the pin or post insulator to earth. This current will normally be less than 0.3mA which flows phasephase or phase-ground. This current is held low to reduce tracking and erosion, especially under polluted conditions. Metal helical ties form an intermediate electrode and can cause discharge problems at the ends if bare. Connecting helical ties with any insulating piercing connectors (IPCs) or use of semi-conducting plastic ties eliminates this problem. For a covered conductor line, insulation piercing connectors (IPC) are used. IPC contains teeth that penetrate through the insulation to have contact with the conductor and complete a connection. Tables 20 and 21 show the relevant data of Copper and ACSR Covered Conductors, respectively. Spacer cables are also alternatives to Covered Cables and perform well in areas with dense trees. Spacer cables are of bundled configuration using a messenger wire with a polymetric support cradle holding up the three phases. The spacer cables’ reactive impedance is smaller because it significantly reduces spacing than typical overhead constructions.

54

Power Cables & Wires Technical Manual Table 20: Copper Single Layer Covered Conductors Data Weight Per Copper Size 1000 ft. (lbs.) Cover O.D. Content (AWG StranThick. Covered Per or ding (mils) (mils) 1000 ft. XLPE PE kcmil) (lbs.)

DC Allowable Resistance Ampacity Ω/1000 + ft.@20°C

6

7

30

238

81

90.3

90.3

0.503

130

4

7

30

285

128.9

140.8

140.8

0.316

175

2

7

45

373

204.9

227.1

227.1

0.199

230

1/0

7

60

477

326.1

363.3

363.3

0.125

305

2/0

7

60

522

410.9

453.3

453.3

0.0992

350

3/0

7

60

570

518.1

565.6

565.6

0.0788

405

4/0

7

60

626

653.3

707.6

707.6

0.0625

465

250

19

60

677

771.9

825.4

825.4

0.0530

520

300

19

60

729

926.2

984.6

984.6

0.0442

580

350

19

60

779

1080.6

1144.5

1144.5

0.0380

640

500

37

80

950

1543.8

1637.2

1637.2

0.0278

785

750

61

80

1128

2315.6

2422.8

2422.8

0.0182

995

1000

61

95

1307

3087.5

3234

3234

0.0140

1180

Source: Southwire

55

Power Cables & Wires Technical Manual Table 21: 2-Layer 15kV ACSR Tree Wire Size (AWG or kcmil)

Stranding

1/0

6/1

2/0

Conductor Diameter (mils)

Covering Thickness (mils)

Cable O.D. (mils)

Rated Strength (lbs)

Weight per 1000 ft. (lbs)

Inner Layer

Outer Layer

398

75

75

698

4161

255

6/1

447

75

75

747

5045

303

3/0

6/1

502

75

75

802

6289

362

4/0

6/1

563

75

75

863

7933

432

266.8

18/1

609

75

75

909

6536

441

266.8

26/7

642

75

75

942

10735

452

336.4

18/1

684

75

75

984

8246

536

336.4

26/7

720

75

75

1020

13395

555

336.4

30/7

741

75

75

1041

16435

621

397.5

18/1

743

75

75

1043

9443

611

397.5

24/7

772

75

75

1072

13870

609

477

24/7

846

75

75

1146

16340

719

477

26/7

858

75

75

1158

18525

762

477

30/7

883

75

75

1183

22610

854

556.5

18/1

879

75

75

1179

13015

813

556.5

24/7

914

75

75

1214

18810

828

556.5

26/7

927

75

75

1227

21470

878

636

18/1

940

75

75

1240

14915

912

636

24/7

977

75

75

1277

20900

936

636

26/7

990

75

75

1290

23940

993

795

26/7

1108

80

80

1428

29925

1234

795 45/7 Source: Southwire

1063

80

80

1383

20995

1031

56

Power Cables & Wires Technical Manual 9.3 Insulated Cables Majority of insulated cables are utilized for underground transmission and distribution systems. Being insulated for voltages higher than 2 kV, that these cables are typically shielded. 9.3.1 Construction The fundamental difference between non-shielded and shielded cables is the inclusion of outer conducting components in the cable system. The basic components of a shielded cable are shown below.

Figure 6: Construction of Shielded Power Cable Conductor The conductors used in shielded cables are basically the same as those used in non-shielded cables, with copper and aluminum as the conductor. Conductor Shield or Screen The conductor shield is usually a semi-conducting material applied over the conductor circumference to shield out the surface irregularities of the conductor. With this shield, the resulting dielectric field lines will not be distorted by the shape of the outer strands or other conductor contours. It prevents the formation of destructive discharges at the interface between the conductor and insulation. Otherwise, the electrical stress around the conductors would produce partial discharges on the surface of the insulation which deteriorates it and eventually results to cable failure. Also, it is essential that this stress control layer be compatible with the conductor and the cable insulation. 57

Power Cables & Wires Technical Manual This layer also provides a smooth and compatible surface for the application of the insulation. The conductor shield is extruded simultaneously with the insulation for a void-free bond between conductor shield and insulation. The shield may also be used to facilitate splicing and termination of the cable. Insulation This is the part of the cable that is relied upon to insulate the conductor from other conductor or conductive object or from ground. The differences between the insulation for shielded cables as compared to non-shielded cables include material, process technology, and testing. The insulation thickness is primarily influenced by the operating voltage. Therefore, the higher the voltage, the thicker the insulation. Insulation Shield or Screen This absorbs the symmetrical radial stresses and discharges on the surfaces of the insulation. It protects the cables from induced potentials. Shields help attenuate, make uniform and reduce the surge potential stresses on the insulation. It increases safety to humans and removes the risk of fire due to electrical discharges on the cable surface. The insulation shield or screen is a two-part system composed of an auxiliary and a primary shield. An auxiliary shield is usually a semi-conducting, non-metallic material over the insulation circumference. It must be smooth, compatible with the insulation, and exhibit an acceptably low voltage drop throughout its thickness. A commonly used auxiliary shield consists of an extruded semi-conducting polymer to permit easy removal during field termination, but yet to remain uniformly bonded to the insulation throughout the cable length. A primary shield is a metallic shield over the circumference of the auxiliary shield. It may consist of copper tape or Concentric Neutral (CN) wires. These concentric neutral wires are usually annealed. 58


CN wires serve two purposes, namely; they function as the metallic component of the insulation shield and as a conductor for the neutral return current. Their crosssectional area must be properly sized in order to function as the neutral conductor. The primary shield must be capable of conducting the summation of the “leakage” currents to the nearest ground with an acceptable voltage drop. In some cases, it must also be capable of conducting fault currents. The primary shield, by itself, without an intervening auxiliary shield, cannot achieve acceptable physical contact with the insulation surface. A relatively resilient auxiliary shield is necessary to eliminate arcing between the insulation surface and the primary shield. If the insulation shield is effectively at ground potential, no resulting distortion of the electrostatic flux or equipotential lines will occur. The grounding of the insulation shield is the electrical connection between the metallic component of the insulation shield and the system ground. This grounding of the insulation shield results in symmetrical dielectric fields. Electrostatic flux lines are spaced symmetrically and perpendicular to equipotential lines. The equipotential lines are concentric and parallel with respect to each other, the conductor shield and the insulation shield. The presence of the shielding results in field lines as depicted in Figure 7. In addition, grounding promotes personnel safety by minimizing potentials on the outer surface of the cable and its accessories. The shielding of the cable system can either be singlepointed or multiple-pointed grounding. A single-point grounded system is frequently referred to as an open circuit shield. Since the shield is grounded at a single point, there is no closed loop for the flow of induced shield currents. A multiple-point grounded system, on the other hand, is one that has grounds at more than one point. It is frequently called a closed or shortcircuit shield system. 59


Each of the arrangements has its particular advantages and disadvantages for selection. Knowledge of the total system should be taken into account when making these decisions. In a shielded cable, the voltage difference between conductor and electrical ground is contained within the cable. For a non-shielded cable, the voltage difference between conductor and electrical ground is divided between the cable insulation and any intervening air or other materials. Insulation Conductor Shield Conductor

Insulation Shield

Electrostatic Flux Lines

Equipotential Lines

Figure 7: Electrical Field of a Shielded Cable

60

Power Cables & Wires Technical Manual In Figure 7, observe that the field lines are closer to each other near the conductor shield as compared to the insulation shield. The radial stresses or voltage gradients increase near the conductor. Jackets/Sheaths These cable components provide environmental protection over the insulation shielding system. The material used can be an extruded jacket of synthetic material, metal sheaths/wires, armoring, or a combination of these types of materials. 9.3.2 Electrical Losses in Cables When the cable is energized and carrying load, heat, which must be dissipated to the surrounding medium, is generated by the conductor, dielectric and sheath losses. The heat generated by these losses in the conductor, the dielectric, the sheath and armor has to pass to the surrounding medium, which may be the ground, air, water or some other material. The current carrying capacity of an electric cable is normally dictated by the maximum temperature of the conductor. The components of the cable, in addition to meeting the electrical requirements, must also have as low a thermal resistivity, as possible, to ensure that the heat can be dissipated efficiently. If the rate of rise of heat generation is greater than the rate of rise of heat dissipation, the cable temperature will continue to increase which will result in the overheating of the cable and eventual breakdown. 9.3.3 Advantages of Shielded Cables Electrical insulation surrounding a conductor creates a capacitor when the conductor is electrically energized. Thus, all insulated conductors are capacitors. In the majority of non-shielded cable systems, the cable surface makes intermittent contact with an electrical ground. Where intimate contact with this ground is not made, the intervening air 61

Power Cables & Wires Technical Manual spaces also act primarily as capacitors in ac circuits and as resistors in dc circuits. This forms a series of cable dielectric and air dielectric. Voltage across this circuit varies along the length of the cable depending on the voltage across the air gap. The cable surface becomes a floating voltage point in a voltage divider. This floating point voltage can vary considerably, depending on the cable design and the characteristics of the air gap. If the voltage is high enough, the cable surface can experience detrimental surface tracking of arcing discharges to electrical ground. The cable surface can also become potentially hazardous causing an electrical shock if contacted by field personnel. Shielding the cable insulation surface and grounding of this shielding eliminates tracking and arcing discharges. The grounding of this shield prevents the accumulation of an electrical potential on the surface of the cable that could be hazardous to any individual that comes into contact with the cable surface. 10. INSTALLATION OF WIRES AND CABLES 10.1 Maximum Allowable Tensions on Conductors Care should be taken during installation of cables to prevent damage that can result to future service failures. In preparing for a conductor pull, it is just as important to cover the other details as it is to assure that the conductor does not exceed maximum sidewall pressure, minimum bending radii or maximum pulling tensions. These and other considerations can make the difference between a good installation and one with damaged conductors. Mechanical stresses during installation are generally more severe than those encountered while in service. The following information provides guidance in recognizing these conditions and provides a methodology to aid in keeping them within acceptable limits.

62

Power Cables & Wires Technical Manual 10.1.1 Maximum Allowable Tension Calculations should be made whether the pull looks easy or impossible, making the decision as where to pull an obvious choice. When an obscure situation is encountered, the entire pull should be reviewed. This review may include more rigorous calculations or trial pulls. A final decision should be made based on installation factors known to the end user and installer. The sizes of the conduit are determined based on the calculations of clearances, jamming, and fill. Pulling tensions may be evaluated by determining the maximum tension based on the pulling device used, and the maximum tension that can be applied to the conductors. The lesser of these two values is the maximum allowable tension. After calculating the pulling tensions, sidewall pressures may be calculated. Do not exceed the allowable tension stated by the manufacturer of the pulling device or 10,000 pounds, whichever is less. Do not use metallic shielding wires, tapes or braids, or armor not designed for the purpose, in pulling tension calculations. The maximum tension allowed for the conductors are computed as follows: Single Conductor: T=S*A Multiple Conductors: T = N * S * A for 3 or less conductors T = (0.8) * N * S * A for more than 3 conductors where: T = conductor tension, lbs S = conductor stress, lbs/cmil (Table 22) A = conductor area, cmil (Table 23) N = number of conductors 63

Power Cables & Wires Technical Manual Pulling different conductor sizes at the same time is not recommended if the conductor size or other cable characteristics are significantly different. If different size conductors must be pulled, it must be done with care.

Table 22: Maximum Allowable Conductor Stress Cable Type All Power Power Power URD Solid

Material Copper Aluminum Aluminum Aluminum Aluminum Aluminum

Temper soft Hard 3/4 hard AA-8000 1/2 hard Soft

lbs/cmil 0.008 0.008 0.006 0.006 0.003 0.002

Table 23: Concentric Stranded Copper & Aluminum Conductor Area AWG 14 12 10 8 6 4 3 2 1 1/0 2/0 3/0 4/0

cmil 4,110 6,530 10,380 16,510 26,240 41,740 52,620 66,360 83,690 105,600 133,100 167,800 211,600

AWG 250 300 350 400 450 500 600 700 750 800 900 1000 1200

64

cmil 250,000 300,000 350,000 400,000 450,000 500,000 600,000 700,000 750,000 800,000 900,000 1,000,000 1,200,000

Power Cables & Wires Technical Manual 10.1.2 Pulling Tension Calculation The following equations allow the user to calculate the expected pulling tension of a conductor in a conduit pull. Tin=W×L× where;

Tin = W= L= =

tension, lbs. weight of one foot of cable, lbs. length of pull, ft. coefficient of friction for the particular duct material and outer layer of the cable.

The weight of the cable and the length of the pull can be determined with great accuracy. The one variable that varies tremendously is the value of the coefficient of friction—it can vary from 0.05 to 1.0. Even when the materials used in the duct and jacket are known, the type and amount of lubricant can be an important factor in this variation. 10.1.3 Coefficient of Friction The coefficient of dynamic friction (μ) is a measure of the friction between a moving conductor and the conduit. The coefficient of friction can have a large impact on the tension calculation. Table 24: Typical Coefficients of Dynamic Friction (μ) for Cables with an Adequate Cable Lubrication During a Pull Cable Outer Jacket or Insulation Type THHN/THWN (Nylon)

Conduit Type EMT PVC 0.28 0.24

Type XHHW, USE, RHH/RHW (XLPE)

0.25

65

0.14

Power Cables & Wires Technical Manual 10.1.4 Conductor Configuration The configuration of three single-conductors in a conduit is determined by the ratio of the conduit inner diameter (D) to the outer diameter (d) of one of the single conductors (D/d ratio). D d ≥ 2.5

D d < 2.5

D

Cradled

Triangular

Figure 8: Configuration of Three Single Conductors

A cradled configuration develops when three single-conductors are pulled into a conduit where the D/d ratio is 2.5 or greater. A triangular configuration develops when three single-conductors are pulled into a conduit where the D/d ratio is less than 2.5. 10.1.5 Weight Correction Factor This configuration of conductors can affect the tension. A weight correction factor (ω) is used in the tension equations to account for this effect. This is given by the following equations: Single Conductor: =1

Three Conductor (Triangular):

Three Conductor (Cradled):

66


Four Conductors or More

To be conservative, it is recommended that the three-conductor (triangular) factor be used when pulling two conductors. 10.1.6 Tension Formulas Horizontal Straight Section: Tout = WL+Tin Inclined and Vertical Section: Pulling up: Tout = WL(sin + cos) + Tin (lbs) Pulling Down: Tout = WL(sin + cos) + Tin (lbs) Elbows and Bends (approximation): Tout = Tin e where;

Tout = Tin = W= L= = = = = e=

tension out of a section, lbs tension into a section, lbs total cable weight, lbs/ft straight section length, ft coefficient of dynamic friction weight correction factor straight section angle from horizontal, radians bend section angle, radians 2.71 natural logarithm base

67

Power Cables & Wires Technical Manual 10.1.7 Conductor Jamming There is a tendency where cables may jam against the inside of the conduit when the diameter of each cable is about one-third the inner diameter of the duct. This commonly occurs when the cables go around a bend or a series of bends. Jamming increases the pulling tension to a point that it can damage the cable. Thus, the jam ratio of the cables needs to be evaluated. The equation for the jam ratio of three cables in a duct is as follows: Jam ratio = 1.05 D d where;

1.05

D= d=

factor to account the possible ovality of the conduit in a bend and for the cable of having a slightly different diameter at any point inside diameter of the duct or conduit outer diameter of each of the three cables

When the jam ratio falls between 2.6 and 3.2, jamming is probable if there are bends in the run. Thus, to avoid possible problem with conductor jamming, it is advisable to avoid pulls where the jam ratio is between 2.6 and 3.2. 10.2 Sidewall Pressure Sidewall pressure is the vector force that exists on the cable as it is pulled through a bend. Because the surface area of the bend is smaller in small radius bends, that force is concentrated over a much smaller area. Most of the time sidewall pressure is the limiting factor in a cable pull. It is calculated by the following equations: Single-conductor cable or multiple-conductor cable under common jacket:

68


Three Conductor (Triangular):

Three Conductor (Cradled):

where;

Sp = T= = R=

sidewall pressure, lbs/ft tension coming out of the bend, lbs weight correction factor bend radius, ft

Table 25: Sidewall Bearing Pressure Limits Cable Type Instrumentation 600 V non-shielded control 600 V power 5 to 15 kV shielded power 25 to 46 kV power

SWBP, lbs/ft 100 300 500 500 300

10.3 Bending Radius The following are the minimum values for the radii to which insulated cables may be bent during installation. These limits do not apply to conduit bends, sheaves or other curved surfaces around which the cable may be pulled under tension while being installed. Larger radii bends may be required for such conditions to limit 69

Power Cables & Wires Technical Manual sidewall pressure. In all cases the minimum radii specified refers to the inner surface of the cable and not to the axis of the cable. The minimum bending radii for both single and multiple-conductor cable with or without lead sheath and without metallic shielding or armor are as follows:

Table 26: Minimum Bending Radii for Power and Control Cables without Metallic Shielding or Armor

Thickness of Conductor Insulation, inches 0.156 and less 0.157 to 0.315 0.316 and over

Overall Diameter of cables, inches 2.001and 1.000 and less 1.001 to 2.000 larger Minimum Bending Radius as Multiple of Cable Diameter 4

5

6

5

6

7

-

7

8

Source: Okonite

70

Power Cables & Wires Technical Manual Table 27: Minimum Bending Radii for Power and Control Cables with Metallic Shielding or Armor, as Multiple of Cable Diameter Type of Cable Power Armored, flat tape or wire type 12... Armored, smooth aluminum sheath, up to; . ...0.75 inches cable diameter 10*. ...0.76 to 1.5 inches cable diameter 12... ...over 1.5 inches cable diameter 15... Armored, corrugated sheath or . ...interlocked type 7... ...with shielded single conductor 12... ...with shielded multi-conductor **... Non-armored, flat or corrugated . ...tape shielded single conductor 12... ...tape shielded multi-conductor **... ...multi-conductor overall tape shield 12... ...LCS with PVC jacket 15... Non-armored, concentric neutral 8... Non-armored, flat strap shielded 8... Non-armored, wire shielded ***.. * with shielded conductors 12 ** 12 times single conductor diameter or 7 times overall cable diameter — whichever is greater *** See Power and control cables without metallic shielding LCS = longitudinally applied corrugated shield Source: Okonite

71

Control 12... . 10*. 12... 15... . 7... 12... **... . 12... **... 12... 15... —... —... —...


11. PACKAGING The usual cut for small diameter building wires is 150 meter and is packaged in boxes. However, for bigger diameter wires and power cables, these usually come in 300 meter rolls. For special and other cutting or packaging requirements, this has to be specified and coordinated with the wires and cables manufacturer. 12. CABLE/WIRE APPLICATION In ordering wires/cables, it is important that the manufacturer knows the intended application of the wires/cables. This in order that they can recommend the type of cable best suited for the application. The usual service conditions for cables are indoor/outdoor application in wet, damp, and/or dry environment. However, for cables that are to be used in special application or condition, this has to be communicated to the manufacturer. 13. CABLE INSTALLATION METHOD Knowledge of the cable installation method to be used is important for the manufacturer since the current carrying capacity of the cable will depend on where the cables are to be laid such as in open air, raceway, cable tray, conduit or directly buried. This is due to the heat generated by the cables due to their close proximity and the capability of the type of cable installation to dissipate this generated heat. Per Philippine Electrical Code (PEC), certain de-rating factor has to be applied depending on the particular installation method. 14. COLOR CODING In accordance with the PEC, certain color coding is required for conductors of a multi-core cable. Ground conductors shall have a continuous white, white stripe or gray outer finish. On the other hand, live wires can have any color, except the foregoing. Equipment grounding conductor, however, shall have a continuous green color or a continuous green color with one or more yellow stripes. 72

Power Cables & Wires Technical Manual For jacketed cords furnished with appliances, one conductor having its insulation colored light blue, with the other conductors having their insulation of a readily distinguishable color other than white or gray. For electric space-heating cables, the lead wire shall have the following color identification to indicate the circuit voltage on which it is to be used: (1) 115 volt, nominal – yellow (2) 208 volt, nominal – blue (3) 230 volt, nominal – red (4) 265 volt, nominal – brown (5) 460 volt, nominal - orange 15. REFERENCE STANDARDS Wires and cables are usually made to comply with certain reference standard (e.g. Philippine National Standard (PNS), IEC, ASTM, ICEA, AIEC, NEMA, UL, etc.) Some PNS on wires and cables are listed in Annex C. 16. STORAGE Another important consideration or information needed to be communicated to the wire manufacturer/supplier is the storage of the cable at site, whether it will be stored indoor or outdoor. If the cable will be stored outdoor and subjected to the elements, depending on the cable insulation or construction and the sealing of its terminals, the cable performance may be degraded. Likewise, for power conductors on reels, especially when it is expected to be stored outdoors for extended periods, special attention should also be taken on the material of the cable reel. Should the reels be made of wood, the reel may rot after some time making it difficult to transport the cable to another site.

73

Power Cables & Wires Technical Manual Hereunder are some use and storage suggestions: (1) Upon receipt, cable protective covering should be thoroughly scrutinized for possible signs of damage during delivery. If evidence of damage is found, inform the carrier immediately. (2) During unloading, make sure that the equipment used does not have contact with the cable surface and its protective covering. When a crane is being used, a cradle supporting the reel flanges or a shaft through the arbor hole should be used. If unloading is being done with the use of a forklift, the forks must lift the reel at 90° to the flanges and must be long enough to reach both flanges. The fork must not make contact with the cable surface or the cable protective covering. (3) If an inclined ramp is used during unloading, the ramp must be wide enough to have contact with both flanges. When controlling the decent of the reel, it should be done through the use of the reel flanges and not the surface of the cable. (4) The reels should not be dropped from the delivering vehicle to the ground whatever the circumstance. (5) The weight of the reel and cable must be allowed to rest on the flanges, which, in turn, should be resting on a hard surface to prevent the flanges from sinking and shifting part of said weight to the cables. 74

Power Cables & Wires Technical Manual (6) Reels should be stored in an area where no falling debris of construction material or other objects that can damage the cable. (7) Cable should not be stored in an area where chemicals or petroleum can be spilled or sprayed on the cable. (8) Reels of cable with unjacketed sheath or armor (aluminum or steel) should be stored indoors. Unjacketed sheath or armor easily corrodes when exposed outside. (9) Care must be taken when a reel of cable is rolled from one point to another, see to it that there are no objects on the surface area which could have contact and damage the cable surface or its protective covering. (10)Keep cable away from open fires or sources of heat. (11)Cable ends must always be sealed to prevent the entrance of moisture. 17. AVAILABLE CABLE HANDLING EQUIPMENT AT SITE It will be important for the cable and wire manufacturer/supplier to know whether there will be any cable handling equipment available at site so that they can prepare the means to unload the cables safely from the transport vehicle. If a cable handling equipment is available at site, its capacity has to be communicated to the manufacturer/supplier so as to ensure that it is capable of handling the weight of the cable. 18. SAFEGUARDS FOR INSTALLING WIRES AND CABLES IN CONDUIT Investigations have shown that cable failures often can be attributed to damage caused during installation due to carelessness, inexperience and inability to observe certain simple precautions. In order to eliminate such preventable causes of electrical shutdowns and loss of production, the following procedures should be followed: 75


18.1 Before Pulling Wire/Cable (1) Know and observe all Philippine Electrical Code rules regarding installation. (2) Check the conduit and wire/cable sizes and actual overall diameters in order to be sure that the approved "fill" will not be exceeded. Do not "crowd" the conduit. (3) Check the type of wire/cable to be installed. (4) Consider the use of larger conduits or additional pull boxes. (5) Check any obstruction on the conduit. (6) To loosen any burrs, pull a short mandrel or plug closely approximating the diameter of the conduit and clean out any remaining dirt or foreign matter, follow it up with a swab. 18.2 While Pulling Wire/Cable (1) To prevent short bends, sharp edges and "crossover", always have a man feed wire straight into a conduit by hand or over a large diameter sheave for large conductors/cables. (2) Remove all lashings used for temporary bunching of individual wires/cables before they enter the conduit. (3) Lead-out wires at all pull boxes and conduits. Feed them in again for the next run. (4) Never pull directly around short right angled bends. 18.3 After Pulling Wire/Cable Shut off the exposed ends of the excess wire/cable on the reel with a tape to prevent moisture from entering the wire/cable. 19. SAFEGUARD FOR SWITCHBOARD AND SIMILAR OPEN WIRING To avoid cutting or deforming the insulation at the contact point use wide tape or straps with rounded edges instead of narrow strings when binding groups of wires, especially non-braided wires.

76

Power Cables & Wires Technical Manual 20. WIRE/CABLE ORDERING FORM In order to guide the user, electrical designer or the purchaser in correctly ordering or specifying the cable or wire that is needed for his specific use and for the wire and cable manufacturer/supplier to have the necessary information to know the specific needs of his customer so that he can give a correct price quotation, a wire/cable ordering form has been developed in Annex D.

77


78

ANNEXES

79

80


ANNEX A Table A1. Conductor Types and Sizes for 115/230-Volt, 3-Wire, Single-Phase Dwelling Services and Feeders. Conductor Types RHH, RHW, RHW-2, THHN, THHW, THW, THW-2, THWN, THWN-2, XHHW, XHHW-2, SE, USE, USE-2 Conductor mm2

Service or Feeder Rating (Amperes)

Copper

Aluminum

22 30 30 38

30 38 50 60

100 110 125 150

50 60 80 100

80 100 125 150

175 200 225 250

125 175 200

175 250 325

300 350 400

81

Power Cables & Wires Technical Manual Table A2. Ampacities of Not More Than Three Single Insulated Conductors, Rated 0 Through 2 000 Volts, Supported on a Messenger, Based on Ambient Air Temperature of 40°C

Conductor Size mm2 125 150 175 200 250 325 375 400 500

75°C Type RH, RHW, THHW, THW, THWN, XHHW, ZW 316 363 390 416 496 576 630 659 741

Temperature Rating of Conductor (See Table 3.10.1.13.) 90°C 75°C 90°C

Types THHN, THHW, THW-2, THWN-2, RHH, RWH-2, USE-2, XHHW-2, ZW-2 COPPER 369 423 460 486 581 674 740 771 870

Types RH, RHW, THHW, THW, THWN, ZHHW 248 285 310 327 392 458 505 529 606

Type THHN, THHW, RHH, XHHW, RHW-2, XHHW-2, THW-2, THWN-2, USE-2, ZW-2 ALUMINUM 288 331 360 382 458 535 590 617 709

Table A3. Ampacities of Insulated Single Copper Conductor Cables Triplexed in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C

Conductor Size mm2 125 175 250 375 400 500

Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity 105°C 105°C 90°C Type Type 90°C Type Type MV-90 MV-105 MV-90 MV-105 370 410 375 420 460 510 465 520 580 640 580 650 740 825 720 810 770 860 750 845 870 970 840 940

82

Power Cables & Wires Technical Manual Table A4. Ampacities of Insulated Single Aluminum Conductor Cables Triplexed in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C



Table A5. Ampacities of Insulated Single Copper Conductor Isolated in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C


Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 5 001–15 000 15 001–35 000 Volts Volts Volts Ampacity Ampacity Ampacity 90°C 105°C 90°C 105°C 90°C 105°C Type Type Type Type Type Type MVMVMVMVMVMV90 105 90 105 90 105 435 485 435 485 430 480 545 605 545 600 540 595 695 775 685 765 680 755 890 990 875 980 860 960 925 1 030 910 1 020 895 1 000 1 060 1 185 1 050 1 030 1 030 1 145 83

Power Cables & Wires Technical Manual Table A6. Ampacities of Insulated Single Aluminum Conductor Isolated in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C


Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 5 001–15 000 15 001–35 000 Volts Volts Volts Ampacity Ampacity Ampacity 90°C 105°C 90°C 105°C 90°C 105°C Type Type Type Type Type Type MVMVMVMVMVMV90 105 90 105 90 105 340 380 340 380 340 375 425 475 425 475 425 470 545 605 535 600 530 590 700 780 690 770 680 755 730 815 720 805 705 790 845 940 830 930 815 910

Table A7. Ampacities of an Insulated Three-Conductor Copper Cable Isolated in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C


Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity 105°C 105°C 90°C Type Type 90°C Type Type MV-90 MV-105 MV-90 MV-105 315 350 355 395 390 435 430 485 485 545 535 600 610 680 665 735 635 705 690 765 695 780 760 850 84

Power Cables & Wires Technical Manual Table A8. Ampacities of an Insulated Three-Conductor Aluminum Cable Isolated in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C



Table A9. Ampacities of an Insulated Triplexed or Three SingleConductor Copper Cables in Isolated Conduit in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C



85

Power Cables & Wires Technical Manual Table A10. Ampacities of an Insulated Triplexed or Three SingleConductor Aluminum Cables in Isolated Conduit in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C



Table A11. Ampacities of an Insulated Three-Conductor Copper Cable in Isolated Conduit in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C



86

Power Cables & Wires Technical Manual Table A12. Ampacities of an Insulated Three-Conductor Aluminum Cable in Isolated Conduit in Air Based on Conductor Temperatures of 90°C and 105°C and Ambient Air Temperature of 40°C



87

Power Cables & Wires Technical Manual Table A13. Ampacities of Three Single-Insulated Copper Conductors in Underground Electrical Ducts (Three Conductors per Electrical Duct) Based on Ambient Earth Temperature of 20°C, Electrical Duct Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures of 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity Conductor 105°C 105°C Size 90°C Type Type 90°C Type Type mm2 MV-90 MV-105 MV-90 MV-105 One Circuit (See Figure 3.10.1.60, Detail 1.) 125 315 340 320 340 175 380 410 385 410 250 470 505 465 500 375 580 625 560 605 400 600 650 580 630 500 660 710 630 680 Three Circuits (See Figure 3.10.1.60, Detail 2.) 125 255 275 255 275 175 310 330 305 325 250 375 405 370 395 375 455 490 435 470 400 475 510 454 490 500 520 555 490 530 Six Circuits (See Figure 3.10.1.60, Detail 3.) 125 205 220 205 220 175 245 265 240 260 250 300 325 290 310 375 360 390 345 370 400 375 405 360 385 500 405 440 385 410

88

Power Cables & Wires Technical Manual Table A14. Ampacities of Three Single-Insulated Aluminum Conductors in Underground Electrical Ducts (Three Conductors per Electrical Duct) Based on Ambient Earth Temperature of 20°C, Electrical Duct Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures of 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity Conductor 105°C 105°C Size 90°C Type Type 90°C Type Type mm2 MV-90 MV-105 MV-90 MV-105 One Circuit (See Figure 3.10.1.60, Detail 1.) 125 245 265 245 265 175 300 320 300 325 250 370 400 370 400 375 465 500 450 485 400 485 520 470 505 500 535 580 520 555 Three Circuits (See Figure 3.10.1.60, Detail 2.) 125 200 215 195 215 175 240 260 240 255 250 295 320 290 315 375 365 390 350 380 400 380 405 365 395 500 420 455 400 435 Six Circuits (See Figure 3.10.1.60, Detail 3.) 125 160 175 160 170 175 190 205 195 205 250 240 255 230 250 375 285 310 275 300 400 295 325 285 315 500 330 355 315 340

89

Power Cables & Wires Technical Manual Table A15. Ampacities of Three Insulated Copper Conductors Cabled Within an Overall Covering (Three-Conductor Cable) in Underground Electrical Ducts (One Cable per Electrical Duct) Based on Ambient Earth Temperature of 20°C, Electrical Duct Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures of 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity Conductor 105°C 105°C Size 90°C Type Type 90°C Type Type mm2 MV-90 MV-105 MV-90 MV-105 One Circuit (See Figure 3.10.1.60, Detail 1.) 125 285 310 305 330 175 350 375 370 395 250 430 460 450 485 375 525 565 540 580 400 545 585 560 600 500 590 635 605 650 Three Circuits (See Figure 3.10.1.60, Detail 2.) 125 240 260 250 265 175 290 310 300 320 250 355 380 360 385 375 425 460 425 460 400 440 480 440 480 500 480 515 480 510 Six Circuits (See Figure 3.10.1.60, Detail 3.) 125 195 215 200 215 175 235 265 240 270 250 290 310 290 305 375 345 370 335 360 400 360 385 350 375 500 385 415 375 400

90

Power Cables & Wires Technical Manual Table A16. Ampacities of Three Insulated Aluminum Conductors Cabled Within an Overall Covering (Three-Conductor Cable) in Underground Electrical Ducts (One Cable per Electrical Duct) Based on Ambient Earth Temperature of 20°C, Electrical Duct Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures of 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity Conductor 105°C 105°C Size 90°C Type Type 90°C Type Type mm2 MV-90 MV-105 MV-90 MV-105 One Circuit (See Figure 3.10.1.60, Detail 1.) 125 225 240 240 260 175 275 305 290 310 250 340 365 355 385 375 420 455 435 470 400 435 475 450 490 500 490 530 505 535 Three Circuits (See Figure 3.10.1.60, Detail 2.) 125 185 200 195 210 175 225 245 235 250 250 280 300 285 305 375 340 370 345 370 400 355 385 360 385 500 395 425 395 425 Six Circuits (See Figure 3.10.1.60, Detail 3.) 125 155 165 155 165 175 185 200 190 200 250 230 245 230 245 375 275 300 270 290 400 285 315 280 300 500 315 340 310 330

91

Power Cables & Wires Technical Manual Table A17. Ampacities of Single Insulated Copper Conductors Directly Buried in Earth Based on Ambient Earth Temperature of 20°C, Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures of 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity Conductor 105°C 105°C Size 90°C Type Type 90°C Type Type 2 mm MV-90 MV-105 MV-90 MV-105 One Circuit, Three Conductors (See Figure 3.10.1.60, Detail 9.) 125 460 500 430 465 175 560 610 530 570 250 690 745 650 700 375 835 900 795 855 400 870 940 830 890 500 970 1 045 920 995 Two Circuits, Six Conductors (See Figure 3.10.1.60, Detail 10.) 125 425 460 405 430 175 510 550 490 525 250 630 680 600 645 375 765 825 730 785 400 800 860 760 820 500 880 950 845 910

92

Power Cables & Wires Technical Manual Table A18. Ampacities of Single Insulated Aluminum Conductors Directly Buried in Earth Based on Ambient Earth Temperature of 20°C, Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures of 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity Conductor 105°C 105°C Size 90°C Type Type 90°C Type Type 2 mm MV-90 MV-105 MV-90 MV-105 One Circuit, Three Conductors (See Figure 3.10.1.60, Detail 9.) 125 365 390 340 365 175 440 475 410 445 250 540 580 510 545 375 660 710 630 670 400 685 740 655 700 500 770 830 730 785 Two Circuits, Six Conductors (See Figure 3.10.1.60, Detail 10.) 125 355 360 315 340 175 405 435 380 410 250 495 530 470 505 375 605 650 575 620 400 630 675 595 645 500 700 775 670 720

93

Power Cables & Wires Technical Manual Table A19. Ampacities of Three Insulated Copper Conductors Cabled Within an Overall Covering (Three-Conductor Cable), Directly Buried in Earth Based on Ambient Earth Temperature of 20°C, Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures of 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity Conductor 105°C 105°C Size 90°C Type Type 90°C Type Type mm2 MV-90 MV-105 MV-90 MV-105 One Circuit (See Figure 3.10.1.60, Detail 5.) 125 360 390 375 405 175 435 470 455 490 250 530 570 550 590 375 640 690 660 710 400 670 720 685 740 500 720 775 740 800 Two Circuits, (See Figure 3.10.1.60, Detail 6.) 125 335 340 325 350 175 405 435 415 445 250 490 525 500 535 375 590 635 600 645 400 610 660 625 670 500 655 705 665 720

94

Power Cables & Wires Technical Manual Table A20. Ampacities of Three Insulated Aluminum Conductors Cabled Within an Overall Covering (Three-Conductor Cable), Directly Buried in Earth Based on Ambient Earth Temperature of 20°C, Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures of 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity Conductor 105°C 105°C Size 90°C Type Type 90°C Type Type mm2 MV-90 MV-105 MV-90 MV-105 One Circuit (See Figure 3.10.1.60, Detail 5.) 125 280 305 295 315 175 340 370 355 385 250 420 450 435 470 375 515 555 535 575 400 535 575 555 595 500 590 640 610 655 Two Circuits, (See Figure 3.10.1.60, Detail 6.) 125 260 280 270 290 175 315 340 325 350 250 385 415 395 425 375 475 510 480 520 400 495 530 500 540 500 540 580 550 590

95

Power Cables & Wires Technical Manual Table A21. Ampacities of Three Triplexed Single Insulated Copper Conductors Directly Buried in Earth Based on Ambient Earth Temperature of 20°C, Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity Conductor 105°C 105°C Size 90°C Type Type 90°C Type Type mm2 MV-90 MV-105 MV-90 MV-105 One Circuit, Three Conductors (See Figure 3.10.1.60, Detail 7.) 125 405 435 385 405 175 485 570 465 500 250 590 635 565 605 375 715 770 675 730 400 745 805 705 760 500 815 875 760 820 Two Circuits, Six Conductors (See Figure 3.10.1.60, Detail 8.) 125 365 390 350 375 175 440 475 420 450 250 535 575 510 545 375 640 690 610 655 400 670 720 635 680 500 730 785 680 735

96

Power Cables & Wires Technical Manual Table A22. Ampacities of Three Triplexed Single Insulated Aluminum Conductors Directly Buried in Earth Based on Ambient Earth Temperature of 20°C, Arrangement per Figure 3.10.1.60, 100 Percent Load Factor, Thermal Resistance (RHO) of 90, Conductor Temperatures 90°C and 105°C Temperature Rating of Conductor (See Table 3.10.1.61) 2 001–5 000 Volts 5 001–35 000 Volts Ampacity Ampacity 90°C 105°C 90°C 105°C Conductor Size Type Type Type Type mm2 MV-90 MV-105 MV-90 MV-105 One Circuit, Three Conductors (See Figure 3.10.1.60, Detail 7.) 125 175 250 375 400 500

315 380 465 575 595 660

345 415 500 620 645 715

300 365 445 545 565 625

320 395 480 585 605 670

Two Circuits, Six Conductors (See Figure 3.10.1.60, Detail 8.) 125 175 250 375 400 500

285 345 420 515 535 590

305 370 455 555 575 635

97

275 330 405 480 500 555

295 450 435 520 540 595

Power Cables & Wires Technical Manual Table A23. Minimum Wire-Bending Space at Terminals

Wire Size mm2 125 150 175 200 250 325 375 400

Wires per Terminal 2 3 mm mm

1 mm 215d 250e 305e 330e 350e 380e 405e 430e

(50) (75) (75) (75) (75) (75) (75) (75)

215d 250d 305e 330e 350e 400e 460e 480e

(50) (50) (50) (75) (75) (75) (75) (75)

230b 280b 330e 350e 380e 455e 510e 560e

(25) (25) (25) (75) (75) (75) (75) (75)

4 or more mm 250 300 350d 380e 400e 480e 560e 610e

(75) (75) (75) (75) (75)

1. Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector in a direction perpendicular to the enclosure wall. 2. For removable and lay-in wire terminals intended for only one wire, bending space shall be permitted to be reduced by the following number of millimeters: a 13 mm b 25 mm c 40 mm d 50 mm e 75 mm 3. This column shall be permitted to determine the required wire-bending space for compact stranded aluminum conductors in sizes up to 500 mm2 and manufactured using AA-8000 series electrical grade aluminum alloy conductor material in accordance with 3.10.1.14.

98

Power Cables & Wires Technical Manual Table A24. Full-Load Current, Three-Phase Alternating-Current Motors The following values of full-load currents are typical for motors running at speeds usual for belted motors and motors with normal torque characteristics. The voltages listed are rated motor voltages. The currents listed shall be permitted for system

voltage ranges of 220 to 240, 380 to 415, and 440 to 480 volts.

Horsepower ½ ¾ 1 1½ 2 3 5 7½ 10 15 20 25 30 40 50 60 75 100 125 150 200 250 300 350 400 450 500

Induction-Type Squirrel Cage and Wound Rotor (Amperes) 230 400 460 Volts Volts Volts 2.2 1.3 1.1 3.2 1.8 1.6 4.2 2.3 2.1 6.0 3.3 3.0 6.8 4.3 3.4 9.6 6.1 4.8 15.2 9.7 7.6 22 14 11 28 18 14 42 27 21 54 34 27 68 44 34 80 51 40 104 66 52 130 83 65 154 103 77 192 128 96 248 165 124 312 208 156 360 240 180 480 320 240 — 403 302 — 482 361 — 560 414 — 636 477 — 711 515 — 786 590

Synchronous-Type Unity Power Factor* (Amperes) 230 400 460 Volts Volts Volts — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 53 33.6 26 63 40.8 32 83 52 41 104 66.4 52 123 81.6 61 155 104 78 202 134.4 101 253 168 126 302 201.3 151 400 268 201 — — — — — — — — — — — — — — — — — —

*For 90 and 80 percent power factor, the figures shall be multiplied by 1.1 and 1.25, respectively.

99

Power Cables & Wires Technical Manual Table A25. Conversion Table of Polyphase Design B, C, and D Maximum Locked-Rotor Currents for Selection of Disconnecting Means and Controllers as Determined from Horsepower and Voltage Rating and Design Letter For use only with 4.30.9.10, 4.40.2.2, 4.40.5.1 and 4.55.1.8(c). Maximum Motor Locked-Rotor Current in Amperes, Two- and Three-Phase, Design B, C, and D* 230 Volts 400 volts 460 Volts Rated Horsepower B, C, D E B, C, D E B, C, D E ½ 20 20 12. 12 10 10 ¾ 25 25 14.5 14.5 12.5 12.5 1 30 30 16.5 16.5 15 15 1½ 40 40 22 22 20 20 2 50 50 32 32 25 25 3 64 73 41 46.5 32 36.5 5 92 122 59 78 46 61 7½ 127 183 81 116.5 63.5 91.5 10 162 225 104.5 145.5 81 113 15 232 337 149.5 217.5 116 169 20 290 449 183 283.5 145 225 25 365 562 237 364 183 281 30 435 674 278 430 218 337 40 580 824 368.5 523 290 412 50 725 1030 463.5 658 363 515 60 870 1236 582 827 435 618 75 1085 1545 724 1031 543 773 100 1450 1873 965 1247 725 937 125 1815 2341 1211 1561.5 908 1171 150 2170 2809 1447 1873.5 1085 1405 200 2900 3745 1933.5 2497.5 1450 1873 250 — — 2435.5 3128 1825 2344 300 — — 2937.5 3750.5 2200 2809 350 — — 3449.5 4433 2550 3277 400 — — 3867 4993.5 2900 3745 450 — — 4487 5818 3250 4214 500 — — 4829.5 6237.5 3625 4682 *Design A motors are not limited to a maximum starting current or locked rotor current.

100

Power Cables & Wires Technical Manual Table A26 Ampacities of Two or Three Insulated Conductors, Rated 0 through 2000 Volts, Within an Overall Covering (Multiconductor Cable), in Raceway in Free Air Based on Ambient Air Temperature of 30ºC Temperature Rating of Conductor. See Table 3.10.1.13 750C 900C 600C 750C 900C Types Types THHN, THHN, Types THHW, Types THHW, RH, THW-2, RH, THW-2, RHW, Types THWN-2, RHW, THWN-2, THHW, Types TW, RHH, THHW, RHH, THW, TW UF RHW-2, THW, RHW-2, THWN, USE-2, THWN, USE-2, XHHW, XHHW, XHHW XHHW, ZW XHHW-2, XHHW-2, ZW-2 ZW-2 COPPER ALUMINUM 600C

Conductor Size mm2

125 150 175 200 250

205 234 250 274 315

245 281 300 328 378

276 317 340 371 427

160 185 199 218 254

192 221 238 261 303

217 250 270 295 342

*Unless otherwise specifically permitted elsewhere in this Code, the overcurrent protection for these conductor types shall not exceed 15 amperes for 2.0 mm2 (1.6 mm dia.), 20 amperes for 3.5 mm2 (2.0 mm dia.), and 30 amperes for 5.5 mm2 (2.6 mm dia.) copper; or 15 amperes for 3.5 mm2 (2.0 mm dia.) and 25 amperes for 5.5 mm2 (2.6 mm dia.) aluminum and copper-clad aluminum.

101

Power Cables & Wires Technical Manual Table A27. Ampacities of Multiconductor Cables with Not More than Three Insulated Conductors, Rated 0 Through 2000 Volts, in Free Air Based on Ambient Air Temperature of 40ºC (For Types TC, MC, MI, UF, and USE Cables) Temperature Rating of Conductor. See Table 3.10.1.13. 750C 850C 900C 600C 750C 850C 900C COPPER ALUMINUM 125 212 274 305 320 166 214 239 250 150 237 306 341 357 186 240 268 280 175 257 332 371 388 202 261 292 304 200 281 363 406 425 222 287 317 334 250 321 416 465 487 255 330 368 385 *Unless otherwise specifically permitted elsewhere in this Code, the overcurrent protection for these conductor types shall not exceed 15 amperes for 2.0 mm2 (1.6 mm dia.), 20 amperes for 3.5 mm2 (2.0 mm dia.), and 30 amperes for 5.5 mm2 (2.6 mm dia.) copper; or 15 amperes for 3.5 mm2 (2.0 mm dia.), and 25 amperes for 5.5 mm2 (2.6 mm dia.) aluminum and copper-clad aluminum. Conductor Size mm2

600C

102

3 Electrical Duct (Fig. B-310-2, Detail 2) Conductor Size (mm2)

103 125 175 250 400

Types RHW, THHW, THW, THWN, XHHW, USE RHO 60 LF 50 410 503 624 794

RHO 90 LF 100 344 418 511 640

RHO 120 LF 100 327 396 484 603

6 Electrical Duct (Fig. B-310-2, Detail 3) Types RHW, THHW, THW, THWN, XHHW, USE COPPER RHO RHO RHO 60 90 120 LF LF LF 50 100 100 386 295 275 472 355 330 583 431 400 736 534 494

9 Electrical Duct (Fig. B-310-2, Detail 4)




Types RHW, THHW, THW, THWN, XHHW, USE


Types RHW, THHW, THW, THWN, XHHW, USE ALUMINUM RHO RHO RHO 60 90 120 LF LF LF 50 100 100 302 230 214 369 277 258 457 337 313 581 421 389


RHO 60 LF 50 369 446 545 674

RHO 90 LF 100 270 322 387 469

RHO 120 LF 100 252 299 360 434

RHO 60 LF 50 320 393 489 626

RHO 90 LF 100 269 327 401 505

RHO 120 LF 100 256 310 379 475

RHO 60 LF 50 288 350 430 538

RHO 90 LF 100 211 252 305 375

RHO 120 LF 100 197 235 284 347


Table A28. Ampacities of Single Insulated Conductors, Rated 0 through 2000 Volts, in Nonmagnetic Underground Electrical Ducts (One Conductor per Electrical Duct), Based on Ambient Earth Temperature of 20ºC, Electrical Duct Arrangement per Figure B-310-2, Conductor Temperature 75ºC

Conductor Size (mm2)

104 125 175 250 400 500





6 Electrical Duct 1 Electrical Duct (Fig. B-310-2, Detail 3) (Fig. B-310-2, Detail 1) Types RHW, THHW, THW, THWN, XHHW, USE


COPPER RHO 60 LF 50 297 363 444 552 628

RHO 90 LF 100 265 321 389 478 539

RHO 120 LF 100 256 310 375 459 518

RHO 60 LF 50 280 340 414 511 579

RHO 90 LF 100 222 267 320 388 435





ALUMINUM RHO 120 LF 100 209 250 299 362 405

RHO 60 LF 50 258 312 377 462 522

RHO 90 LF 100 184 219 261 314 351

RHO 120 LF 100 169 202 240 288 321

RHO 60 LF 50 233 285 352 446 521

RHO 90 LF 100 207 252 308 386 447

RHO 120 LF 100 201 244 297 372 430

RHO 60 LF 50 219 267 328 413 480

RHO 90 LF 100 174 209 254 314 361

RHO 120 LF 100 163 196 237 293 336

RHO 60 LF 50 505 245 299 374 433

RHO 90 LF 100 144 172 207 254 291

RHO 120 LF 100 132 158 190 233 266


Table A29. Ampacities of Three Insulated Conductors, Rated 0 through 2000 Volts, Within an Overall Covering (Three-Conductor Cable) in Underground Electrical Ducts (One Cable per Electrical Duct) Based on Ambient Earth Temperature of 20ºC, Electrical Duct Arrangement per Figure B-310-2, Conductor Temperature 75ºC

Table A30. Ampacities of Three Single Insulated Conductors, Rated 0 Through 2000 Volts, in Underground Electrical Ducts (Three Conductors per Electrical Duct) Based on Ambient Earth Temperature of 20ºC, Electrical Duct Arrangement per Figure B-310-2, Conductor Temperature 75ºC

Types Types Types Conductor RHW, THHW, THW, RHW, THHW, THW, RHW, THHW, THW, THWN, XHHW, USE THWN, XHHW, USE THWN, XHHW, USE Size mm2 COPPER RHO 60 LF 50

105

125 150 175 200

334 373 409 442

RHO 90 LF 100

290 321 351 376

RHO 120 LF 100

279 308 337 361

RHO 60 LF 50

310 344 377 394

RHO 90 LF 100

236 260 283 302

RHO 120 LF 100

RHO 60 LF 50

RHO 90 LF 100

RHO 120 LF 100

220 242 264 280

281 310 340 368

192 210 228 243

176 192 209 223

Types Types Types RHW, THHW, THW, RHW, THHW, THW, RHW, THHW, THW, THWN, XHHW, USE THWN, XHHW, USE THWN, XHHW, USE ALUMINUM RHO 60 LF 50

261 293 321 349

RHO 90 LF 100

227 252 276 297

RHO 120 LF 100

218 242 265 284

RHO 60 LF 50

242 272 296 321

RHO 90 LF 100

RHO 120 LF 100

RHO 60 LF 50

RHO 90 LF 100

RHO 120 LF 100

185 204 222 238

172 190 207 220

220 245 266 288

150 165 179 191

137 151 164 174


1 Electrical Duct 3 Electrical Duct 6 Electrical Duct 1 Electrical Duct 3 Electrical Duct 6 Electrical Duct (Fig. B-310-2, Detail 1) (Fig. B-310-2, Detail 2) (Fig. B-310-2, Detail 3) (Fig. B-310-2, Detail 1) (Fig. B-310-2, Detail 2) (Fig. B-310-2, Detail 3)

Power Cables & Wires Technical Manual Table A31. Ampacities of Two or Three Insulated Conductors, Rated 0 Through 2000 Volts, Cabled Within an Overall (Two- or Three-Conductor) Covering, Directly Buried in Earth, Based on Ambient Earth Temperature of 20ºC, Arrangement per Figure B-310-2, 100 Percent Load Factor, Thermal Resistance (Rho) of 90

Conductor Size mm2

125 175 250 400 500

1 Cable 2 Cable (Fig. B-310-2, (Fig. B-310-2, Detail 5) Detail 6) 600C 750C 600C 750C Types Types RHW, RHW, THHW, THHW, Types Types THW, THW, UF UF THWN, THWN, XHHW, XHHW, USE USE COPPER — 333 — 308 — 401 — 370 — 481 — 442 — 585 — 535 — 657 — 600

1 Cable 2 Cable (Fig. B-310-2, (Fig. B-310-2, Detail 5) Detail 6) 600C 750C 600C 750C Types Types RHW, RHW, THHW, THHW, Types Types THW, THW, UF UF THWN, THWN, XHHW, XHHW, USE USE ALUMINUM — 261 — 241 — 315 — 290 — 381 — 350 — 473 — 433 — 545 — 497

Note: For ampacities of Type UF cable in underground electrical ducts, multiply the ampacities shown in the table by 0.74.

106

Power Cables & Wires Technical Manual Table A32. Ampacities of Three Triplexed Single Insulated Conductors, Rated 0 Through 2000 Volts, Directly Buried in Earth Based on Ambient Earth Temperature of 20ºC, Arrangement per Figure B-310-2, 100 Percent Load Factor, Thermal Resistance (Rho) of 90

Conductor Size mm2 125 175 250 400 500

See Fig. B-310-2, Details 8 750C 600C 750C TYPES USE UF USE COPPER 370 — 336 445 — 403 436 — 483 654 — 587 744 — 665

See Fig. B-310-2, Details 7

600C UF — — — — —

See Fig. B-310-2, See Fig. B-310-2, Details 7 Details 8 600C 750C 600C 750C TYPES UF USE UF USE ALUMINUM — 289 — 263 — 349 — 316 — 424 — 382 — 525 — 471 — 608 — 544

Table A33. Ampacities of Three Single Insulated Conductors, Rated 0 Through 2000 Volts, Directly Buried in Earth Based on Ambient Earth Temperature of 20ºC, Arrangement per Figure B-310-2, 100 Percent Load Factor, Thermal Resistance (Rho) of 90

Conductor Size mm2

600C UF

See Fig. B-310-2, Detail 10 750C 600C 750C TYPES USE UF USE

125 175 250 400

— — — —

429 516 626 767

See Fig. B-310-2, Detail 9

See Fig. B-310-2, See Fig. B-310-2, Detail 9 Detail 10 600C 750C 600C 750C TYPES UF USE UF USE

COPPER — — — —

ALUMINUM 394 474 572 700

107

— — — —

335 403 490 605

— — — —

308 370 448 552

Power Cables & Wires Technical Manual Table A34. Maximum Number of Conductors and Fixture Wires in Electrical Metallic Tubing (Based on Table 9.1.1.1)

Type RH RHH, RHW, RHW-2 RH, RHH, RHW, RHW-2

TW

RHH*, RHW*, RHW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, THHW, THW RHH*, RHW*, THW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, TW, THW, THHW, THW-2

Conductor Size [mm2 (mm dia.)] 2.0 (1.6) 3.5 (2.0) 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 2.0 (1.6)

CONDUCTORS Raceway Size (mm) 15

20

25

32

40

50

65

80

90

100

6 4 4 3 2 1 1 1 1 0 0 0 0 0 00 0 0 0 0 0 0 0 8 6 5 2 6

10 8 7 6 5 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 15 11 8 5 10

16 13 11 9 8 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 25 19 14 8 16

28 23 20 17 13 7 5 4 3 1 1 1 1 1 1 1 1 1 0 0 0 0 0 43 33 24 13 28

39 31 27 23 18 9 8 6 4 3 2 2 1 1 1 1 1 1 1 1 0 0 0 58 45 33 18 39

64 51 46 38 30 16 13 10 7 5 4 4 3 3 1 1 1 1 1 1 1 1 1 96 74 55 30 64

112 90 80 66 53 28 22 17 13 9 7 6 5 5 3 3 3 2 2 1 1 1 1 168 129 96 53 112

169 136 120 100 81 42 34 26 20 13 11 10 8 7 5 5 4 4 3 3 2 2 1 254 195 145 81 169

221 177 157 131 105 55 44 34 26 17 15 13 11 9 7 6 6 5 4 4 3 3 2 332 255 190 105 221

282 227 201 167 135 70 56 44 33 22 19 17 14 12 9 8 7 7 6 5 4 4 3 424 326 243 135 282

3.5 (2.0) 5.5 (2.6)

4 3

8 6

13 10

23 18

31 24

51 40

90 70

136 106

177 138

227 177

8.0 (3.2)

1

4

6

10

14

24

42

63

83

106

14 22 30 38

1 1 1 1

3 1 1 1

4 3 2 1

8 6 4 3

11 8 6 4

18 13 10 7

32 24 17 12

48 36 26 18

63 47 34 24

81 60 44 31

50 60 80 100 125 150 175 200 250

0 0 0 0 0 0 0 0 0

1 1 1 0 0 0 0 0 0

1 1 1 1 1 1 0 0 0

2 1 1 1 1 1 1 1 1

3 3 2 1 1 1 1 1 1

6 5 4 3 3 2 1 1 1

10 9 7 6 5 4 4 3 3

16 13 11 9 7 6 6 5 4

20 17 15 12 10 8 7 7 6

26 22 19 16 13 11 10 9 7

*Types RHH, RHW, and RHW-2 without outer covering.

108

Power Cables & Wires Technical Manual Table A34. Continued Conductor Type Size [mm2 (mm dia.)] RHH*, RHW*, 325 RHW-2*, TW, 375 THW, THHW, 400 THW-2 500 THHN, THWN, 2.0 (1.6) THWN-2 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 FEP, FEPB, PFA, 2.0 (1.6) PFAH, TFE 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 PFA, PFAH, TFE 38 PFA, PFAH, TFE, Z

Z

XHH, XHHW, XHHW-2, ZW

50 60 80 100 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2)


20

25

32

40

50

65

90

100

0 0 0 0 12 9 5 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 12 9 6 3 2 1 1 1

0 0 0 0 22 16 10 6 4 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 21 15 11 6 4 3 1 1

0 0 0 0 35 26 16 9 7 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 34 25 18 10 7 5 3 2

1 0 0 0 61 45 28 16 12 7 5 4 3 2 1 1 1 1 1 1 1 1 0 0 0 60 43 31 18 12 9 6 4

1 1 1 0 84 61 38 22 16 10 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 81 59 42 24 17 12 8 6

1 1 1 1 138 101 63 36 26 16 11 8 7 6 5 4 3 3 2 1 1 1 1 1 1 134 98 70 40 28 20 13 9

2 1 1 1 241 176 111 64 46 28 20 15 12 10 8 7 6 5 4 4 3 2 1 1 1 234 171 122 70 50 35 24 16

3 3 3 2 364 266 167 96 69 43 30 22 19 16 13 11 9 7 6 6 5 4 3 3 2 354 258 185 106 75 53 36 25

4 4 4 3 476 347 219 126 91 56 40 29 25 20 17 14 11 10 9 8 6 5 4 4 3 462 337 241 138 98 69 47 33

6 5 5 4 608 443 279 161 116 71 51 37 32 26 22 18 15 13 11 10 8 7 5 5 4 590 430 309 177 126 88 60 42

1 0 0 0 14 10 6 4 3 1 1 1 8 6 5 2

1 1 1 1 25 18 11 7 5 3 1 1 15 11 8 5

1 1 1 1 41 29 18 11 8 5 3 2 25 19 14 8

3 3 2 1 72 51 31 20 14 9 6 4 43 33 24 13

5 4 3 2 98 69 42 27 19 13 8 6 58 45 33 18

8 6 5 4 161 114 70 44 31 21 13 10 96 74 55 30

14 11 9 8 282 200 122 77 54 37 22 18 168 129 96 53

21 17 14 11 426 302 185 117 82 56 34 28 254 195 145 81

27 22 18 15 556 394 241 153 107 74 45 36 332 255 190 105

35 29 24 19 711 504 309 195 137 94 57 46 424 326 243 135

*Types RHH, RHW, and RHW-2 without outer covering.

109

80

Power Cables & Wires Technical Manual Table A34. Continued

Type XHH, XHHW, XHHW-2, ZW

Conductor Size [mm2 (mm dia.)] 14 22 30

XHH, XHHW, XHHW-2

38 50 60 80 100 125 150 175 200 250 325 375 400 500


20

25

32

40

50

65

80

90

100

1 1 1

3 2 1

6 4 3

10 7 5

14 10 7

22 16 11

39 28 20

60 43 31

78 56 40

100 72 51

1 1 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 0 0 0 0 0 0 0 0 0

1 1 1 1 1 1 1 1 0 0 0 0 0 0

4 3 2 1 1 1 1 1 1 1 1 0 0 0

5 4 3 3 2 1 1 1 1 1 1 1 1 0

8 7 6 5 4 3 3 2 1 1 1 1 1 1

15 13 10 9 7 6 5 4 4 3 2 1 1 1

23 19 16 13 11 9 8 7 6 5 4 3 3 2

30 25 21 17 14 12 10 9 8 6 5 4 4 3

38 32 27 22 18 15 13 11 10 8 6 5 5 4

FIXTURE WIRES Type FFH-2, RFH-2, FHH-3 SF-2, SFF-2

SF-1, SFF-1 RFH-1, RFHH-2, TF, TFF, XF, XFF RFHH-2, TF, TFF, XF, XFF XF, XFF TFN, TFFN PF, PFF, PGF, PGFF, PAF, PTF, PTFF, PAFF HF, HFF, ZF, ZFF, ZHF

KF-2, KFF-2

KF-1, KFF-1

XF, XFF

Conductor Size (mm2) 0.75 1.25 0.75 1.25 2.0 0.75 0.75

15 8 7 10 8 7 18 14

20 14 12 18 15 12 33 24

1.25 2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

11 8 22 17 21 16 12 27 20 14 39 27 19 13 8 46 33 22 14 9 4 3

19 15 38 29 36 28 21 47 35 25 69 48 33 23 15 82 57 38 25 16 8 6

Raceway Size (mm) 25 32 24 41 20 34 30 52 25 43 20 34 53 92 39 68 31 25 63 48 59 46 34 77 56 41 111 78 54 37 25 133 93 63 41 27 13 10

55 43 108 83 103 79 60 133 98 72 193 136 93 64 43 230 161 108 72 47 23 18

40 56 47 71 58 47 125 92

50 92 78 116 96 78 206 152

74 58 148 113 140 108 81 181 133 98 262 185 127 87 58 313 220 148 98 64 31 24

123 96 244 186 231 179 134 298 220 161 433 305 209 144 96 516 362 244 161 105 51 40

Note: This table is for concentric stranded conductors only. For compact stranded conductors, Table A35 should be used.

110

Power Cables & Wires Technical Manual Table A35. Maximum Number of Compact Conductors in Electrical Metallic Tubing (Based on Table 9.1.1.1) Type


THW, THW-2, THHW

8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

THHN, THWN, THWN-2

XHHW, XHHW2

15

COMPACT CONDUCTORS Raceway Size (mm) 20 25 32 40 50 65

80

90

100

2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 — 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0

4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 — 4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 5 4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0

69 53 40 29 21 18 15 13 11 8 7 6 6 5 4 3 3 2 — 78 48 34 26 22 18 15 12 10 8 7 6 5 4 4 4 3 90 66 48 34 26 22 18 15 13 10 9 8 7 6 4 3 3 3

90 70 52 38 27 23 20 17 14 11 9 8 8 6 5 4 4 3 — 102 63 45 34 29 24 20 16 13 11 10 9 7 6 5 5 3 117 87 63 45 34 29 24 20 17 13 11 10 9 7 6 5 5 4

115 89 67 49 34 30 25 21 18 14 12 1110 8

6 5 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 — 7 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 8 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0

11 9 6 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0 — 13 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0 15 11 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0

16 12 9 7 4 4 3 3 2 1 1 1 1 1 1 1 1 1 — 18 11 8 6 5 4 3 3 1 1 1 1 1 1 1 1 1 20 15 11 8 6 5 4 3 3 2 1 1 1 1 1 1 1 1

26 20 15 11 8 7 5 5 4 3 3 2 1 1 1 1 1 1 — 29 18 13 10 8 7 6 5 4 3 3 2 1 1 1 1 1 34 25 18 13 10 8 7 6 5 4 3 3 2 1 1 1 1 1

46 35 26 19 13 12 10 8 7 5 5 4 4 3 2 1 1 1 — 52 32 23 17 14 12 10 8 6 5 5 4 4 3 2 2 1 59 44 32 23 17 14 12 10 8 7 6 5 4 4 3 2 2 1

7 5 5 4 — 130 81 58 43 37 30 25 21 16 14 12 11 9 7 6 6 4 149 111 81 58 43 37 31 25 21 17 14 13 11 9 8 6 6 5

Definition: Compact stranding is the result of a manufacturing process where the standard conductor is compressed to the extent that the interstices (voids between strand wires) are virtually eliminated.

111

Power Cables & Wires Technical Manual Table A36. Maximum Number of Conductors and Fixture Wires in Electrical Nonmetallic Tubing (Based on Table 9.1.1.1) CONDUCTORS Type RH RHH, RHW, RHW-2 RH, RHH, RHW, RHW-2

TW

RHH*, RHW*, RHW-2*, THHW, THW, THW-2 RHH*, RHW*, RHW-2*, THHW, THW RHH*, RHW*, RHW-2*, THHW, THW, THW-2 RHH*, RHW*, RHW-2*, TW, THW, THHW, THW-2


15 4 3 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 5 4 1 4

20 8 7 6 5 4 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 13 10 7 4 8

3.5 (2.0) 5.5 (2.6)

3 3

7 5

8.0 (3.2)

1

14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Raceway Size 25 15 12 10 9 7 3 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 22 17 13 7 15

(mm) 32 27 21 19 16 13 6 5 4 3 1 1 1 1 1 1 1 1 1 0 0 0 0 0 40 31 23 13 27

40 37 29 26 22 17 9 7 6 4 3 2 1 1 1 1 1 1 1 1 1 0 0 0 55 42 32 17 37

50 61 49 43 36 29 15 12 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 92 71 52 29 61

12 9

21 17

29 23

49 38

3

5

10

14

23

2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0

4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0

7 5 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0

10 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0

17 13 9 6 5 5 4 3 2 2 1 1 1 1 1 1 1

*Type RHH, RHW, and RHW-2 without outer covering.

112


CONDUCTORS Type THHN, THWN, THWN-2

FEP, FEPB, PFA, PFAH, TFE

PFA, PFAH, TFE PFA, PFAH, TFE, Z

Z


Conductor Size [mm2 (mm dia.)] 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38

15 10 7 4 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 10 7 5 3 1 1 1 1

20 18 13 8 5 3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 18 13 9 5 4 2 1 1

50 60 80 100 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30

0 0 0 0 12 8 5 3 1 1 1 1 7 5 4 1 1 1 1

1 1 1 1 22 15 9 6 4 3 1 1 13 10 7 4 3 1 1

113

Raceway Size 25 32 23 15 8 6 4 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0 31 23 16 9 6 4 3 1 1 1 1 1 38 27 16 10 7 5 3 2 22 17 13 7 5 4 2

(mm) 32 58 42 26 15 11 7 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0 56 41 29 17 12 8 5 4

40 80 58 36 21 15 9 6 5 4 3 3 2 1 1 1 1 1 1 1 1 0 77 56 40 23 16 11 8 5

50 132 96 60 35 25 15 11 8 7 5 4 4 3 2 2 1 1 1 1 1 1 128 93 67 38 27 19 13 9

3 2 1 1 68 48 29 18 13 9 5 4 40 31 23 13 9 7 5

4 4 3 2 93 66 40 25 18 12 7 6 55 42 32 17 13 9 6

7 6 5 4 154 109 67 42 30 20 12 10 92 71 52 29 21 15 11


CONDUCTORS Type XHH, XHHW, XHHW-2

Conductor Size [mm2 (mm dia.)] 38 50 60 80 100 125 150 175 200 250 325 375 400 500

15 1 0 0 0 0 0 0 0 0 0 0 0 0 0

Raceway Size 25 1 1 1 1 1 1 1 1 0 0 0 0 0 0

20 1 1 1 1 0 0 0 0 0 0 0 0 0 0

(mm) 32 3 3 2 1 1 1 1 1 1 1 1 0 0 0

40 5 4 3 3 2 1 1 1 1 1 1 1 1 0

50 8 7 6 5 4 3 3 2 1 1 1 1 1 1

(mm) 32 39 32 49 40 32 86 64

40 53 45 67 55 45 119 88

50 88 74 111 92 74 197 145

FIXTURE WIRES Type FFH-2, RFH-2, RFHH-3 SF-2, SFF-2


KF-2, KFF-2

KF-1, KFF-1

XF, XFF

Raceway Size 25 21 18 27 22 18 48 35


15 6 5 8 7 5 15 11

20 12 10 15 13 10 28 20

1.25

9

16

29

51

71

117

2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

7 18 13 17 13 10 22 16 12 31 22 15 10 7 38 26 18 12 7 3 3

13 33 25 31 24 18 40 29 22 58 41 28 19 13 69 49 33 22 14 7 5

22 57 43 54 42 31 70 51 38 101 71 49 33 22 121 85 57 38 24 12 9

40 102 78 97 75 56 125 92 68 182 128 88 60 40 217 152 102 68 44 21 17

55 141 107 133 103 77 172 127 93 250 176 121 83 55 298 209 141 93 61 29 23

92 233 178 221 171 128 285 210 154 413 291 200 138 92 493 346 233 154 101 49 38


114

Power Cables & Wires Technical Manual Table A37. Maximum Number of Compact Conductors in Electrical Nonmetallic Tubing (Based on Table 9.1.1.1)

Type THW, THW-2, THHW

THHN, THWN, THWN-2

XHHW, XHHW-2

Conductor Size (mm2) 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

COMPACT CONDUCTORS Raceway Size (mm) 15 20 25 32 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0  1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0

3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0  4 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0

6 4 3 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0  7 4 3 2 1 1 1 1 1 1 1 0 0 0 0 0 0 8 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0

11 8 6 4 3 3 2 1 1 1 1 1 1 1 1 0 0 0  12 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 0 14 10 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 0

40

50

15 11 8 6 4 4 3 3 2 1 1 1 1 1 1 1 1 0  17 10 7 5 5 4 3 2 1 1 1 1 1 1 1 1 1 19 14 10 7 5 5 4 3 3 1 1 1 1 1 1 1 1 1

25 19 14 10 7 6 5 4 4 3 2 2 1 1 1 1 1 1  28 17 12 9 8 6 5 4 3 3 2 2 1 1 1 1 1 32 24 17 12 9 8 7 5 4 3 3 3 2 1 1 1 1 1


115

Power Cables & Wires Technical Manual Table A38 Maximum Number of Conductors and Fixture Wires in Flexible Metal Conduit (Based on Table 9.1.1.1)


TW

RHH*, RHW*, RHW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, THW, THHW, RHH*, RHW*, RHW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, TW, THW, THHW, THW-2



20

25

32

40

50

65

80

90

100

6 5 4 3 3 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9 7 5 3 6

10 8 7 6 5 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 15 11 8 5 10

15 12 11 9 7 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 23 18 13 7 15

24 19 17 14 11 6 5 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 36 28 21 11 24

35 28 25 21 17 9 7 5 4 2 2 1 1 1 1 1 1 1 1 1 0 0 0 53 41 30 17 35

62 50 44 37 30 15 12 10 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 94 72 54 30 62

94 75 67 55 45 23 19 14 11 7 6 5 5 4 3 2 2 1 1 1 1 1 1 141 108 81 45 94

135 108 96 80 64 34 27 21 16 10 9 8 7 6 4 4 3 3 3 2 1 1 1 203 156 116 64 135

184 148 131 109 88 46 37 29 22 14 12 11 9 8 6 5 5 4 4 3 2 2 1 277 212 158 88 184

240 193 171 142 115 60 48 37 28 19 16 14 12 10 8 7 6 6 5 4 3 3 3 361 277 207 115 240

3.5 (2.0) 5.5 (2.6)

5 4

8 6

12 10

19 15

28 22

50 39

75 59

108 85

148 115

193 151

8.0 (3.2)

1

4

6

9

13

23

35

51

69

90

14 22 30 38 50 60 80 100 125 150 175 200 250

1 1 1 1 0 0 0 0 0 0 0 0 0

3 1 1 1 1 1 1 0 0 0 0 0 0

4 3 2 1 1 1 1 1 1 1 0 0 0

7 5 4 2 1 1 1 1 1 1 1 1 1

10 7 5 4 3 3 2 1 1 1 1 1 1

18 13 10 7 6 5 4 3 3 2 1 1 1

27 20 14 10 9 7 6 5 4 3 3 3 2

39 29 21 15 12 10 9 7 6 5 4 4 3

53 39 29 20 17 14 12 10 8 7 6 6 5

69 51 37 26 22 19 16 13 11 9 8 7 6


116

Power Cables & Wires Technical Manual Table A38 Continued

Type RHH*, RHW*, RHW-2*, TW, THW, THHW, THW-2 THHN, THWN, THWN-2



Z


CONDUCTORS Raceway Size (mm)

Conductor Size [mm2 (mm dia.)] 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38

15

20

25

32

40

50

65

80

90

100

0 0 0 0 13 9 6 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 12 9 6 4 2 1 1 1

0 0 0 0 22 16 10 6 4 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 21 15 11 6 4 3 1 1

0 0 0 0 33 24 15 9 6 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 32 24 17 10 7 5 3 2

0 0 0 0 52 38 24 14 10 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 51 37 26 15 11 7 5 3

1 1 1 0 76 56 35 20 14 9 6 4 4 3 2 1 1 1 1 1 1 1 1 1 0 74 54 39 22 16 11 7 5

1 1 1 1 134 98 62 35 25 16 11 8 7 6 5 4 3 3 2 1 1 1 1 1 1 130 95 68 39 28 19 13 9

1 1 1 1 202 147 93 53 38 24 17 12 10 9 7 6 5 4 3 3 2 1 1 1 1 196 143 103 59 42 29 20 14

3 2 2 1 291 212 134 77 55 34 24 18 15 12 10 8 7 6 5 5 4 3 2 2 1 282 206 148 85 60 42 29 20

4 3 3 2 396 289 182 105 76 46 33 24 20 17 14 12 9 8 7 6 5 4 3 3 3 385 281 201 115 82 57 39 27

5 4 4 3 518 378 238 137 99 61 43 32 27 22 18 15 12 11 9 8 7 5 4 4 3 502 367 263 151 107 75 51 36

50 60 80 100 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30

1 1 0 0 15 11 6 4 3 1 1 1 9 7 5 3 1 1 1

1 1 1 1 25 18 11 7 5 3 1 1 15 11 8 5 3 2 1

1 1 1 1 39 28 17 11 7 5 3 2 23 18 13 7 5 4 3

3 2 1 1 61 43 26 17 12 8 5 4 36 28 21 11 8 6 4

4 3 3 2 89 63 39 24 17 12 7 6 53 41 30 17 12 9 6

8 6 5 4 157 111 68 43 30 21 12 10 94 72 54 30 22 16 11

11 9 8 6 236 168 103 65 45 31 19 15 141 108 81 45 33 24 17

17 14 11 9 340 241 148 93 65 45 27 22 203 156 116 64 48 34 24

23 19 15 13 463 329 201 127 89 61 37 30 277 212 158 88 65 47 33

30 24 20 16 605 429 263 166 117 80 49 39 361 277 207 115 85 61 44

117


Type XHH, XHHW, XHHW-2


COMPACT CONDUCTORS Raceway Size (mm) 15

20

25

32

40

50

65

1 1 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 0 0 0 0 0 0 0 0 0

1 1 1 1 1 1 1 1 0 0 0 0 0 0

3 2 2 1 1 1 1 1 1 1 0 0 0 0

5 4 3 3 2 1 1 1 1 1 1 1 1 0

8 7 6 5 4 3 3 2 1 1 1 1 1 1

13 10 9 7 6 5 4 4 3 3 1 1 1 1

80 18 15 13 10 9 7 6 5 5 4 3 2 2 1

90

100

25 21 17 14 12 10 8 7 6 5 4 3 3 3

32 27 23 19 15 13 11 9 8 7 5 4 4 3

FIXTURE WIRES Conductor Size (mm2) FFH-2, RFH-2, RFHH-3 0.75 1.25 SF-2, SFF-2 0.75 1.25 2.0 SF-1, SFF-1 0.75 RFH-1, RFHH-2, TF, 0.75 TFF, XF, XFF RFHH-2, TF, TFF, XF, 1.25 XFF XF, XFF 2.0 TFN, TFFN 0.75 1.25 PF, PFF, PGF, PGFF, 0.75 PAF, PTF, PTFF, PAFF 1.25 2.0 HF, HFF, ZF, ZFF, ZHF 0.75 1.25 2.0 KF-2, KFF-2 0.75 1.25 2.0 3.5 5.5 KF-1, KFF-1 0.75 1.25 2.0 3.5 5.5 XF, XFF 3.5 5.5 Type

15 8 7 11 9 7 19 14

20 14 12 18 15 12 32 24

11

19

9 23 17 22 17 12 28 20 15 41 28 19 13 9 48 34 23 15 10 5 4

15 38 29 36 28 21 47 35 25 68 48 33 23 15 82 57 38 25 16 8 6

Raceway Size 25 22 19 28 23 19 50 37

(mm) 32 35 29 44 36 29 78 58

40 51 43 64 53 43 114 84

50 90 76 113 94 76 201 148

30

47

68

120

23 59 45 56 43 32 72 53 39 105 74 51 35 23 125 88 59 39 25 12 10

36 93 71 88 68 51 113 83 61 164 116 80 55 36 196 138 93 61 40 19 15

53 135 103 128 99 74 165 121 89 239 168 116 80 53 285 200 135 89 58 28 22

94 237 181 225 174 130 290 214 157 421 297 204 140 94 503 353 237 157 103 50 39


118

Power Cables & Wires Technical Manual Table A39 Maximum Number of Compact Conductors in Flexible Metal Conduit (Based on Table 9.1.1.1) Type


THW, THHW, THW-2

8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

THHN, THWN, THWN-2

XHHW, XHHW-2

COMPACT CONDUCTORS Raceway Size (mm) 15 20 25 32 40 50 65

80

90

100

2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0  3 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 3 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0

55 43 32 23 16 14 12 10 8 7 6 5 5 4 3 2 2 1  62 38 28 21 17 14 12 10 8 7 6 5 4 3 3 3 1 71 53 38 28 21 17 15 12 10 8 7 6 5 4 3 3 3 2

75 58 43 32 22 19 16 14 11 9 8 7 6 5 4 3 3 3  85 52 38 28 24 20 17 14 11 9 8 7 6 5 4 4 3 97 72 52 38 28 24 20 17 14 11 9 8 7 6 5 4 4 3

98 76 57 42 29 25 21 18 15 12 10 9 8 7 6 5 5 4  111 69 49 37 31 26 22 18 14 12 10 9 8 6 5 5 4 127 95 69 49 37 31 26 22 18 14 12 11 10 8 6 5 5 4

4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0  4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 5 4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0

6 5 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 0  7 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 8 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0

10 7 5 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0  11 7 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0 13 9 7 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0

14 11 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0  16 10 7 5 4 4 3 2 1 1 1 1 1 1 1 1 0 19 14 10 7 5 4 4 3 2 1 1 1 1 1 1 1 1 1

25 20 15 11 7 6 5 4 4 3 2 2 1 1 1 1 1 1  29 18 13 9 8 6 5 4 3 3 3 2 1 1 1 1 1 33 24 18 13 9 8 7 5 4 4 3 3 2 1 1 1 1 1

38 29 22 16 11 10 8 7 6 4 4 3 3 3 1 1 1 1  43 27 19 14 12 10 8 7 5 5 4 3 3 2 1 1 1 50 37 27 19 14 12 10 8 7 5 5 4 4 3 2 1 1 1


119

Power Cables & Wires Technical Manual Table A40 Maximum Number of Conductors and Fixture Wires in Intermediate Metal Conduit (Based on Table 9.1.1.1)


TW

RHH*, RHW*, RHW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, THHW, THW RHH*, RHW*, RHW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, TW, THW, THHW, THW-2



15

20

25

32

40

50

65

80

90

100

6 5 4 4 3 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 10 7 5 3 6

11 9 8 6 5 3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 17 13 9 5 11

18 14 13 11 8 4 3 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 27 21 15 8 18

31 25 22 18 15 8 6 5 3 2 1 1 1 1 1 1 1 1 1 0 0 0 0 47 36 27 15 31

42 34 30 25 20 10 8 6 5 3 3 2 1 1 1 1 1 1 1 1 1 1 0 64 49 36 20 42

69 56 49 41 33 17 14 11 8 5 4 4 3 3 1 1 1 1 1 1 1 1 1 104 80 59 33 69

98 79 70 58 47 24 19 15 11 7 6 6 5 4 3 3 2 2 1 1 1 1 1 147 113 84 47 98

151 122 108 89 72 38 30 23 18 12 10 9 7 6 5 4 4 3 3 2 1 1 1 228 175 130 72 151

202 163 144 120 97 50 40 31 24 16 14 12 10 9 6 6 5 5 4 3 3 3 2 304 234 174 97 202

261 209 186 154 124 65 52 41 31 20 18 15 13 11 8 7 7 6 5 4 4 4 3 392 301 224 124 261

3.5 (2.0) 5.5 (2.6)

5 4

9 7

14 11

25 19

34 26

56 43

79 61

122 95

163 127

209 163

8.0 (3.2)

2

4

7

12

16

26

37

57

76

98

14 22 30 38 50 60 80 100 125 150 175 200 250

1 1 1 1 1 0 0 0 0 0 0 0

3 2 1 1 1 1 1 1 0 0 0 0

5 4 3 1 1 1 1 1 1 1 0 0

9 6 5 3 3 2 1 1 1 1 1 1

12 9 6 4 4 3 3 2 1 1 1 1

20 15 11 7 6 5 4 4 3 2 1 1

28 21 15 11 9 8 6 5 4 4 3 2

43 32 23 16 14 12 10 8 7 6 4 4

58 43 31 22 19 16 13 11 9 8 6 5

75 56 41 28 24 20 17 14 12 10 8 7


120

Power Cables & Wires Technical Manual Table A40 Continued CONDUCTORS Type RHH*, RHW*, RHW-2*, TW, THW, THHW, THW-2 THHN, THWN, THWN-2



Z


Conductor Size [mm2 (mm dia.)] 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30

Raceway Size (mm) 15

20

25

32

40

50

65

80

90

100

0 0 0

0 0 0

0 0 0

1 0 0

1 1 0

1 1 1

1 1 1

3 2 1

4 3 3

5 4 3

14 10 6 3 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 13 10 7 4 3 1 1 1

24 17 11 6 4 3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 23 17 12 7 5 3 2 1

39 29 18 10 7 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 38 28 20 11 8 5 4 2

68 49 31 18 13 8 5 4 3 3 2 1 1 1 1 1 1 1 1 1 0 66 48 34 19 14 10 6 4

91 67 42 24 17 10 7 5 4 4 3 2 1 1 1 1 1 1 1 1 1 89 65 46 26 19 13 9 6

149 109 68 39 28 17 12 9 8 6 5 4 3 3 2 2 1 1 1 1 1 145 106 76 43 31 21 15 10

211 154 97 56 40 25 17 13 11 9 7 6 5 4 4 3 3 2 1 1 1 205 150 107 61 44 30 21 14

326 238 150 86 62 38 27 20 17 14 12 9 8 7 6 5 4 3 3 3 2 317 231 166 95 67 47 32 22

436 318 200 115 83 51 36 27 23 19 16 13 10 9 8 7 6 5 4 4 3 423 309 221 127 90 63 43 30

562 410 258 149 107 66 47 35 29 24 20 17 13 12 10 9 7 6 5 5 4 545 398 285 163 116 81 56 39

1 1 0 0 16 11 7 4 3 1 1 1 10 7 5 3 1 1 1

1 1 1 1 28 20 12 7 5 3 1 1 17 13 9 5 4 3 1

1 1 1 1 46 32 20 12 9 6 3 3 27 21 15 8 6 4 3

4 3 2 1 79 56 34 21 15 10 6 5 47 36 27 15 11 8 5

5 4 3 3 107 76 46 29 20 14 8 7 64 49 36 20 15 11 7

8 7 6 5 175 124 76 48 33 23 14 11 104 80 59 33 24 18 12

12 10 8 7 247 175 107 68 47 33 20 16 147 113 84 47 35 25 18

19 15 13 10 381 271 166 105 73 50 30 25 228 175 130 72 53 39 27

25 21 17 14 510 362 221 140 98 67 41 33 304 234 174 97 71 52 37

32 27 22 18 657 466 285 180 127 87 53 43 392 301 224 124 92 67 47

121

Power Cables & Wires Technical Manual Table A40 Continued CONDUCTORS Type

Conductor Size [mm2 (mm dia.)]

XHH, XHHW, XHHW-2

38 50 60 80 100 125 150 175 200 250 325 375 400 500


20

25

32

40

50

65

80

90

100

1 1 1 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 0 0 0 0 0 0 0 0 0

2 1 1 1 1 1 1 1 1 0 0 0 0 0

4 3 3 2 1 1 1 1 1 1 1 1 1 0

5 5 4 3 2 1 1 1 1 1 1 1 1 1

9 8 6 5 4 3 3 3 2 1 1 1 1 1

13 11 9 7 6 5 4 4 3 3 2 1 1 1

20 17 14 12 10 8 7 6 5 4 3 3 3 2

27 23 19 16 13 11 9 8 7 6 5 4 4 3

35 30 25 20 17 14 12 10 9 8 6 5 5 4

FIXTURE WIRES Conductor Size (mm2) FHH-2, RFH-2, RFHH-3 0.75 1.25 SF-2, SFF-2 0.75 1.25 2.0 SF-1, SFF-1 0.75 RFH-1, RFHH-2, TF, 0.75 TFF, XF, XFF RFH-2, TF, TFF, XF, XFF 1.25 Type

XF, XFF TFN, TFFN PF, PFF, PGF, PGFF, PAF, PTF, PTFF, PAFF ZF, ZFF, ZHF, HF, HFF

KF-2, KFF-2

KF-1, KFF-1

XF, XFF

2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

Raceway Size (mm) 25 32 26 45 22 38 33 57 27 47 22 38 59 101 43 75

15 9 8 12 10 8 21 15

20 16 13 20 17 13 36 26

12

21

35

10 25 19 23 18 13 30 22 16 44 31 21 14 10 52 37 25 16 10 5 4

17 42 32 40 31 23 52 38 28 75 53 36 25 17 90 63 42 28 18 9 7

27 69 53 66 51 38 85 63 46 123 87 60 41 27 147 103 69 46 30 14 11

40 61 51 77 64 51 137 101

50 100 84 126 104 84 223 165

60

81

133

47 119 91 113 87 66 146 108 79 212 149 103 70 47 253 178 119 79 52 25 19

64 161 123 153 118 89 197 145 107 287 202 139 95 64 342 240 161 107 70 34 26

104 264 201 250 193 145 322 238 175 468 330 227 156 104 558 392 264 175 114 56 43


122

Power Cables & Wires Technical Manual Table A41 Maximum Number of Compact Conductors in Intermediate Metal Conduit (Based on Table 9.1.1.1) Type THW, THW-2, THHW

THHN, THWN, THWN-2

XHHW, XHHW-2


15

8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0  3 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 3 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0

COMPACT CONDUCTORS Raceway Size (mm) 20 25 32 40 50 65 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0  5 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 6 4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0

7 6 4 3 1 1 1 1 1 1 1 1 1 0 0 0 0 0  8 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0 0 9 7 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0 0

13 10 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 0  14 9 6 5 4 3 3 2 1 1 1 1 1 1 1 1 0 16 12 9 6 5 4 3 3 2 1 1 1 1 1 1 1 1 0

17 13 10 7 5 4 4 3 2 1 1 1 1 1 1 1 1 1  19 12 8 6 5 4 4 3 2 1 1 1 1 1 1 1 1 22 16 12 8 6 5 4 4 3 2 1 1 1 1 1 1 1 1

28 22 16 12 8 7 6 5 4 3 3 2 2 1 1 1 1 1  32 20 14 10 9 7 6 5 4 3 3 2 2 1 1 1 1 37 27 20 14 10 9 7 6 5 4 3 3 3 2 1 1 1 1

40 31 23 17 12 10 9 7 6 5 4 4 3 3 2 1 1 1  45 28 20 15 13 10 9 7 6 5 4 4 3 2 1 1 1 52 38 28 20 15 13 11 9 7 6 5 4 4 3 2 1 1 1

80

90

62 48 36 26 18 16 13 11 9 7 6 6 5 4 3 3 3 2  70 43 31 23 20 16 14 11 9 7 7 6 5 4 3 3 2 80 59 43 31 23 20 17 14 11 9 8 7 6 5 4 3 3 2

83 64 48 35 25 21 18 15 13 10 9 8 7 6 5 4 4 3  93 58 41 31 26 22 18 15 12 10 9 8 7 5 4 4 3 107 80 58 41 31 26 22 18 15 12 10 9 8 7 5 4 4 3

100 107 82 62 45 32 27 23 20 16 13 11 10 9 8 6 5 5 4  120 74 53 40 34 28 24 19 15 13 11 10 9 7 6 6 4 138 103 74 53 40 34 29 24 20 16 13 12 11 9 7 6 6 4

Definition: Compact stranding is the result of a manufacturing process where the standard conductor is compressed to the extent that interstices (voids between strand wires) are virtually eliminated.

123

Power Cables & Wires Technical Manual Table A42 Maximum Number of Conductors and Fixture Wires in Liquidtight Flexible Nonmetallic Conduit (Type FNMC-B*) (Based on Table 9.1.1.1)


TW

RHH†, RHW†, RHW-2†, THW, THHW, THW-2 RHH†, RHW†, RHW-2†, THHW, THW RHH†, RHW†, RHW-2†, THW, THHW, THW-2 RHH†, RHW†, RHW-2†, TW, THW, THHW, THW-2



15

20

25

32

40

50

2.0 (1.6) 3.5 (2.0) 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 2.0 (1.6)

3 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 4 3 1 3

6 5 4 3 3 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9 7 5 3 6

10 8 7 6 5 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 15 12 9 5 10

16 13 12 10 8 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 25 19 14 8 16

29 23 21 17 14 7 6 4 3 1 1 1 1 1 1 1 1 1 1 0 0 0 0 44 33 25 14 29

38 30 27 22 18 9 7 6 4 3 2 1 1 1 1 1 1 1 1 1 0 0 0 57 43 32 18 38

62 50 44 36 29 15 12 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 93 71 53 29 62

3.5 (2.0) 5.5 (2.6)

3 1

5 3

8 6

13 10

23 18

30 23

50 39

8.0 (3.2)

1

1

4

6

11

14

23

14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0

3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0

5 3 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0

8 6 4 3 2 2 1 1 1 1 1 1 1 1 0 0 0

11 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0

18 13 9 7 6 5 4 3 3 2 1 1 1 1 1 1 1

*Corresponds to Section 3.51.2.1(2). †Types RHH, RHW, and RHW-2 without outer covering.

124

Power Cables & Wires Technical Manual Table A42 Continued CONDUCTORS Type THHN, THWN, THWN-2



Z



Raceway Size (mm)

2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38

10 8 5 3 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 5 4 1 1 1 1 0

15 13 9 6 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 12 9 6 3 2 1 1 1

20 22 16 10 6 4 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 21 15 11 6 4 3 1 1

25 36 26 16 9 7 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 35 25 18 10 7 5 3 2

32 63 46 29 16 12 7 5 4 3 2 1 1 1 1 1 1 1 1 0 0 0 61 44 32 18 13 9 6 4

40 81 59 37 21 15 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 0 79 57 41 23 17 12 8 5

50 133 97 61 35 25 15 11 8 7 6 5 4 3 3 2 1 1 1 1 1 1 129 94 68 39 27 19 13 9

50 60 80 100 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30

0 0 0 0 9 6 4 2 1 1 0 0 5 4 3 1 1 1 1

1 1 0 0 15 10 6 4 3 1 1 1 9 7 5 3 1 1 1

1 1 1 1 26 18 11 7 5 3 1 1 15 12 9 5 3 2 1

1 1 1 1 42 30 18 11 8 5 3 2 25 19 14 8 6 4 3

3 3 2 1 73 52 32 20 14 9 6 5 44 33 25 14 10 7 5

4 4 3 2 95 67 41 26 18 12 7 6 57 43 32 18 13 9 7

7 6 5 4 156 111 68 43 30 20 12 10 93 71 53 29 22 16 11

125

Power Cables & Wires Technical Manual Table A42 Continued CONDUCTORS Type


XHH, XHHW, XHHW-2

Raceway Size (mm) 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0

38 50 60 80 100 125 150 175 200 250 325 375 400 500

15 1 1 0 0 0 0 0 0 0 0 0 0 0 0

20 1 1 1 1 1 0 0 0 0 0 0 0 0 0

25 1 1 1 1 1 1 1 1 0 0 0 0 0 0

32 4 3 2 1 1 1 1 1 1 1 1 0 0 0

40 5 4 3 3 2 1 1 1 1 1 1 1 1 0

50 8 7 6 5 4 3 3 2 1 1 1 1 1 1

FIXTURE WIRES Type FFH-2, RFH-2 SF-2, SFF-2


KF-2, KFF-2

KF-1, KFF-1

XF, XFF


10 5 4 6 5 4 11 8

15 8 7 11 9 7 19 14

Raceway Size (mm) 20 25 32 15 24 42 12 20 35 19 30 53 15 25 44 12 20 35 33 53 94 24 39 69

40 54 46 69 57 46 122 90

50 89 75 113 93 75 199 147

1.25

7

11

20

32

56

72

119

2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

5 14 10 13 10 7 17 12 9 24 17 12 8 5 29 20 14 9 6 3 1

9 23 17 21 16 12 28 20 15 40 28 19 13 9 48 34 23 15 10 5 3

15 39 30 37 29 21 48 35 26 70 49 34 23 15 83 58 39 26 17 8 6

25 63 48 60 46 35 77 57 42 112 79 54 37 25 134 94 63 42 27 13 10

44 111 85 105 81 61 136 100 73 197 139 95 65 44 235 165 111 73 48 23 18

57 144 110 136 105 79 176 129 95 255 180 123 85 57 304 214 144 95 62 30 23

93 236 180 223 173 129 288 212 156 418 295 202 139 93 499 350 236 156 102 50 39


126

Power Cables & Wires Technical Manual Table A43 Maximum Number of Compact Conductors in Liquidtight Flexible Nonmetallic Conduit (Type FNMC-B*) (Based on Table 9.1.1.1)


THHN, THWN, THWN-2

XHHW, XHHW-2


COMPACT CONDUCTORS Raceway Size (mm) 10 15 20 25 32 1 2 4 7 12 1 1 3 5 9 1 1 2 4 7 1 1 1 3 5 0 1 1 1 3 0 1 1 1 3 0 0 1 1 2 0 0 1 1 1 0 0 1 1 1 0 0 0 1 1 0 0 0 1 1 0 0 0 1 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 —     1 2 4 7 13 1 1 3 4 8 1 1 1 3 6 0 1 1 2 4 0 1 1 1 4 0 1 1 1 3 0 0 1 1 2 0 0 1 1 1 0 0 1 1 1 0 0 0 1 1 0 0 0 1 1 0 0 0 1 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 1 3 5 9 15 1 2 4 6 11 1 1 3 4 8 1 1 1 3 6 0 1 1 2 4 0 1 1 1 4 0 1 1 1 3 0 0 1 1 2 0 0 1 1 1 0 0 1 1 1 0 0 0 1 1 0 0 0 1 1 0 0 0 1 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0

40 15 12 9 6 4 4 3 3 2 1 1 1 1 1 1 1 1 1  17 11 7 6 5 4 3 3 1 1 1 1 1 1 1 1 1 20 15 11 7 6 5 4 3 3 1 1 1 1 1 1 1 1 1

50 25 19 14 11 7 6 5 4 4 3 2 2 1 1 1 1 1 1  28 17 12 9 8 6 5 4 3 3 2 2 1 1 1 1 1 33 24 17 12 9 8 7 5 4 3 3 3 2 1 1 1 1 1

*Corresponds to Section 3.51.2.1(2).

Definition: Compact stranding is the result of a manufacturing process where the standard conductors compressed to the extent that the interstices (voids between strand wires) are virtually eliminated.

127

Power Cables & Wires Technical Manual Table A44 Maximum Number of Conductors and Fixture Wires in Liquidtight Flexible Nonmetallic Conduit (Type FNMC-A*) (Based On Table 9.1.1.1)


TW

RHH†, RHW†, RHW-2†, THW, THHW, THW-2 RHH†, RHW†, RHW-2†, THHW, THW RHH†, RHW†, RHW-2†, THW, THHW, THW-2 RHH†, RHW†, RHW-2†, TW, THW, THHW, THW-2



15

20

25

32

40

50

2.0 (1.6) 3.5 (2.0) 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 2.0 (1.6)

3 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 4 3 1 3

6 4 4 3 3 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9 7 5 3 6

10 8 7 6 5 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 15 12 9 5 10

16 13 11 9 8 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 24 19 14 8 16

28 23 20 17 13 7 5 4 3 1 1 1 1 1 1 1 1 1 0 0 0 0 0 43 33 24 13 28

38 31 27 23 18 9 7 6 4 3 2 1 1 1 1 1 1 1 1 1 0 0 0 58 44 33 18 38

64 51 45 38 30 16 13 10 7 5 4 4 3 3 1 1 1 1 1 1 1 1 1 96 74 55 30 64

3.5 (2.0) 5.5 (2.6)

3 1

4 3

8 6

13 10

23 18

31 24

51 40

8.0 (3.2)

1

1

4

6

10

14

24

14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0

3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0

4 3 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0

8 6 4 3 2 1 1 1 1 1 1 1 1 1 0 0 0

11 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0

18 13 10 7 6 5 4 3 3 2 1 1 1 1 1 1 1

*Correspond to Section 3.51.2.1(1). †Types RHH, RHW,and RHW-2 without outer covering.

128


Type THHN, THWN, THWN-2



Z


Conductor Size [mm2 (mm dia.)] 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30


15

20

25

32

40

50

8 5 3 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 5 4 1 1 1 1 0

13 9 6 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 12 9 6 3 2 1 1 1

22 16 10 6 4 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 21 15 11 6 4 3 1 1

35 25 16 9 6 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 34 25 18 10 7 5 3 2

62 45 28 16 12 7 5 4 3 2 1 1 1 1 1 1 1 1 0 0 0 60 44 31 18 13 9 6 4

83 60 38 22 16 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 0 80 59 42 24 17 12 8 5

137 100 63 36 26 16 11 8 7 6 5 4 3 3 2 1 1 1 1 1 1 133 97 70 40 28 20 13 9

0 0 0 0 9 6 4 2 1 1 1 1 5 4 3 1 1 1 1

1 1 0 0 15 10 6 4 3 1 1 1 9 7 5 3 1 1 1

1 1 1 1 25 18 11 7 5 3 1 1 15 12 9 5 3 2 1

1 1 1 1 41 29 18 11 8 5 3 2 24 19 14 8 5 4 3

3 3 2 1 72 51 31 20 14 9 6 4 43 33 24 13 10 7 5

5 4 3 2 97 69 42 26 18 13 8 6 58 44 33 18 13 10 7

8 6 5 4 161 114 70 44 31 21 13 10 96 74 55 30 22 16 11

129





10

15

20

25

32

40

50

0 0 0 0 0 0 0 0 0 0 0 0 0 0

1 1 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 0 0 0 0 0 0 0 0 0

1 1 1 1 1 1 1 1 0 0 0 0 0 0

4 3 2 1 1 1 1 1 1 1 1 0 0 0

5 4 3 3 2 1 1 1 1 1 1 1 1 0

8 7 6 5 4 3 3 2 1 1 1 1 1 1



KF-2, KFF-2

KF-1, KFF-1

XF, XFF


10 5 4 6 5 4 12 8

15 8 7 11 9 7 19 14

Raceway Size (mm) 20 25 32 14 23 41 12 20 35 18 29 52 15 24 43 12 20 35 33 52 92 24 39 68

40 55 47 70 58 47 124 91

50 92 77 116 96 77 205 152

1.25

7

11

19

31

55

74

122

2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

5 14 10 13 10 7 17 12 9 25 17 12 8 5 29 21 14 9 6 3 1

9 22 17 21 16 12 27 20 15 40 28 19 13 9 48 33 22 15 10 4 3

15 39 29 37 28 21 47 35 25 69 48 33 23 15 82 57 39 25 17 8 6

24 62 47 59 45 34 76 56 41 110 77 53 36 24 131 92 62 41 27 13 10

43 109 83 103 80 60 133 98 72 193 136 94 64 43 231 162 109 72 47 23 18

58 146 112 139 107 80 179 132 97 260 183 126 86 58 310 218 146 97 63 31 24

96 243 185 230 178 133 297 219 161 431 303 209 143 96 514 361 243 161 105 51 40


130

Power Cables & Wires Technical Manual Table A45 Maximum Number of Compact Conductors in Liquidtight Flexible Nonmetallic Conduit (Type FNMC-A*) (Based on Table 9.1.1.1)


THHN, THWN, THWN-2

XHHW, XHHW-2


COMPACT CONDUCTORS Raceway Size (mm) 10 15 20 25 32

40

50

1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 — 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0

16 12 9 6 4 4 3 3 2 1 1 1 1 1 1 1 1 1  18 11 8 6 5 4 3 3 1 1 1 1 1 1 1 1 1 20 15 11 8 6 5 4 3 3 2 1 1 1 1 1 1 1 1

26 20 15 11 8 7 5 5 4 3 3 2 1 1 1 1 1 1  29 18 13 10 8 7 6 5 3 3 3 2 1 1 1 1 1 34 25 18 13 10 8 7 6 5 4 3 3 2 1 1 1 1 1

2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0  2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 3 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0

4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0  4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 5 4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0

*Corresponds to Section 3.51.2.1(1).

131

6 5 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0  7 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 8 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0

11 9 7 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0  13 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0 15 11 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0

Power Cables & Wires Technical Manual Table A46 Maximum Number of Conductors and Fixture Wires in Liquidtight Flexible Metal Conduit (Based on Table 9.1.1.1)


TW




20

25

32

40

50

65

80

90

100

6 5 4 3 3 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9 7 5 3 6

10 8 7 6 5 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 15 12 9 5 10

16 13 12 10 8 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 25 19 14 8 16

29 23 21 17 14 7 6 4 3 1 1 1 1 1 1 1 1 1 1 0 0 0 0 44 33 25 14 29

38 30 27 22 18 9 7 6 4 3 2 1 1 1 1 1 1 1 1 1 0 0 0 57 43 32 18 38

62 50 44 36 29 15 12 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 93 71 53 29 62

93 75 66 55 44 23 18 14 11 7 6 5 4 4 3 2 2 1 1 1 1 1 1 140 108 80 44 93

143 115 102 84 68 36 28 22 17 11 10 8 7 6 4 4 3 3 3 2 1 1 1 215 165 123 68 143

186 149 133 110 89 46 37 29 22 14 13 11 9 8 6 5 5 4 4 3 2 2 1 280 215 160 89 186

243 195 173 144 116 61 48 38 29 19 16 14 12 10 8 7 6 6 5 4 3 3 3 365 280 209 116 243

3.5 (2.0) 5.5 (2.6)

5 3

8 6

13 10

23 18

30 23

50 39

75 58

115 89

149 117

195 152

8.0 (3.2)

1

4

6

11

14

23

35

53

70

91

14 22 30 38 50 60 80 100 125 150 175 200 250

1 1 1 1 0 0 0 0 0 0 0 0 0

3 1 1 1 1 1 1 0 0 0 0 0 0

5 3 2 1 1 1 1 1 1 1 0 0 0

8 6 4 3 2 2 1 1 1 1 1 1 1

11 8 6 4 3 3 2 1 1 1 1 1 1

18 13 9 7 6 5 4 3 3 2 1 1 1

27 20 14 10 8 7 6 5 4 3 3 3 2

41 30 22 15 13 11 9 8 6 5 5 4 3

53 40 29 20 17 15 12 10 8 7 6 6 5

70 52 38 26 23 19 16 13 11 9 8 7 6


132





Z



Conductor Size [mm2 (mm dia.)] 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38

15

20

25

32

40

50

65

80

90

100

0 0 0 0 13 9 6 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 12 9 6 3 2 1 1 1

0 0 0 0 22 16 10 6 4 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 21 15 11 6 4 3 1 1

0 0 0 0 36 26 16 9 7 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 35 25 18 10 7 5 3 2

1 0 0 0 63 46 29 16 12 7 5 4 3 2 1 1 1 1 1 1 1 1 0 0 0 61 44 32 18 13 9 6 4

1 1 1 0 81 59 37 21 15 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 0 79 57 41 23 17 12 8 5

1 1 1 1 133 97 61 35 25 15 11 8 7 6 5 4 3 3 2 1 1 1 1 1 1 129 94 68 39 27 19 13 9

1 1 1 1 201 146 92 53 38 23 17 12 10 8 7 6 5 4 3 3 2 1 1 1 1 195 142 102 58 41 29 20 14

3 2 2 1 308 225 141 81 59 36 26 19 16 13 11 9 7 6 5 5 4 3 3 3 1 299 218 156 89 64 44 30 21

4 3 3 2 401 292 184 106 76 47 33 25 21 17 14 12 10 8 7 6 5 4 3 3 3 389 284 203 117 83 58 40 28

5 4 4 3 523 381 240 138 100 61 44 32 27 23 19 15 12 11 9 8 7 6 5 5 3 507 370 266 152 108 75 52 36

50 60 80 100 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30

1 1 0 0 20 14 8 5 4 2 1 1 9 7 5 3 1 1 1

1 1 1 1 26 18 11 7 5 3 1 1 15 12 9 5 3 2 1

1 1 1 1 42 30 18 11 8 5 3 2 25 19 14 8 6 4 3

3 3 2 1 73 52 32 20 14 9 6 5 44 33 25 14 10 7 5

4 4 3 2 95 67 41 26 18 12 7 6 57 43 32 18 13 9 7

7 6 5 4 156 111 68 43 30 20 12 10 93 71 53 29 22 16 11

11 9 8 6 235 167 102 64 45 31 19 15 140 108 80 44 33 24 17

18 14 12 10 360 255 156 99 69 48 29 23 215 165 123 68 50 36 26

23 19 16 13 469 332 203 129 90 62 38 30 280 215 160 89 66 48 34

30 25 20 17 611 434 266 168 118 81 49 40 365 280 209 116 86 62 44


133





20

25

32

40

50

65

80

90

100

1 1 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 0 0 0 0 0 0 0 0 0

1 1 1 1 1 1 1 1 0 0 0 0 0 0

4 3 2 1 1 1 1 1 1 1 1 0 0 0

5 4 3 3 2 1 1 1 1 1 1 1 1 0

8 7 6 5 4 3 3 2 1 1 1 1 1 1

12 10 9 7 6 5 4 3 3 2 1 1 1 1

19 16 13 11 9 7 6 5 5 4 3 3 3 1

25 21 17 14 12 10 8 7 6 5 4 3 3 3

33 28 23 19 16 13 11 10 8 7 6 5 5 3



KF-2, KFF-2

KF-1, KFF-1

XF, XFF


15 8 7 11 9 7 19 14

20 15 12 19 15 12 33 24

1.25

11

20

2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

9 23 17 21 16 12 28 20 15 40 28 19 13 9 48 34 23 15 10 5 3

15 39 30 37 29 21 48 35 26 70 49 34 23 15 83 58 39 26 17 8 6

Raceway Size 25 24 20 30 25 20 53 39

(mm) 32 42 35 53 44 35 94 69

40 54 46 69 57 46 122 90

50 89 75 113 93 75 199 147

32

56

72

119

25 63 48 60 46 35 77 57 42 112 79 54 37 25 134 94 63 42 27 13 10

44 111 85 105 81 61 136 100 73 197 139 95 65 44 235 165 111 73 48 23 18

57 144 110 136 105 79 176 129 95 255 180 123 85 57 304 214 144 95 62 30 23

93 236 180 223 173 129 288 212 156 418 295 202 139 93 499 350 236 156 102 50 39


134

Power Cables & Wires Technical Manual Table A47 Maximum Number of Compact Conductors Liquidtight Flexible Metal Conduit (Based on Table 9.1.1.1)


THHN, THWN, THWN-2

XHHW, XHHW-2


10

8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0  1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0


4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0  4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 5 4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0

7 5 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0  7 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 9 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0

12 9 7 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0  13 8 6 4 4 3 2 1 1 1 1 1 1 1 1 1 0 15 11 8 6 4 4 3 2 1 1 1 1 1 1 1 1 1 0

15 12 9 6 4 4 3 3 2 1 1 1 1 1 1 1 1 1  17 11 7 6 5 4 3 3 1 1 1 1 1 1 1 1 1 20 15 11 7 6 5 4 3 3 1 1 1 1 1 1 1 1 1

25 19 14 11 7 6 5 4 4 3 2 2 1 1 1 1 1 1  28 17 12 9 8 6 5 4 3 3 2 2 1 1 1 1 1 33 24 17 12 9 8 7 5 4 3 3 3 2 1 1 1 1 1

in

65

80

90

100

38 29 22 16 11 10 8 7 6 4 4 3 3 3 1 1 1 1  43 26 19 14 12 10 8 7 5 4 4 3 3 2 1 1 1 49 37 26 19 14 12 10 8 7 5 5 4 4 3 2 1 1 1

58 45 34 25 17 15 13 11 9 7 6 5 5 4 3 3 3 1  66 41 29 22 19 15 13 10 8 7 6 5 5 4 3 3 2 76 56 41 29 22 19 16 13 11 8 7 6 6 5 4 3 3 2

76 59 44 32 23 20 16 14 12 9 8 7 6 5 4 3 3 3  86 53 38 28 24 20 17 14 11 9 8 7 6 5 4 4 3 98 73 53 38 28 24 20 17 14 11 9 8 7 6 5 4 4 3

99 77 57 42 30 26 21 18 15 12 10 9 8 7 6 5 5 4  112 69 50 37 32 26 22 18 14 12 11 9 8 6 5 5 4 129 95 69 50 37 32 27 22 18 15 12 11 10 8 6 5 5 4


135

Power Cables & Wires Technical Manual Table A48 Maximum Number of Conductors and Fixture Wires in Rigid Metal Conduit (Based on Table 9.1.1.1)

CONDUCTORS Type RH RHH, RHW, RHW-2 RH, RHH, RHW, RHW-2

TW




20

25

32

40

50

65

80

90

100

125

150

6 5 4 3 3 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9 7 5 3 6

10 8 7 6 5 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 15 12 9 5 10

17 13 12 10 8 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 25 19 14 8 17

29 23 21 17 14 7 6 4 3 1 1 1 1 1 1 1 1 1 1 0 0 0 0 44 33 25 14 29

39 32 28 23 19 10 8 6 4 3 2 2 1 1 1 1 1 1 1 1 0 0 0 59 45 34 19 39

65 52 46 38 31 16 13 10 7 5 4 4 3 3 1 1 1 1 1 1 1 1 1 98 75 56 31 65

93 75 66 55 44 23 18 14 11 7 6 5 4 4 3 2 2 1 1 1 1 1 1 140 107 80 44 93

143 115 102 85 68 36 29 22 17 11 10 8 7 6 4 4 4 3 3 2 1 1 1 216 165 123 68 143

191 154 136 113 91 48 38 30 23 15 13 11 10 8 6 5 5 4 4 3 3 3 1 288 221 164 91 191

246 198 176 146 118 61 49 38 29 19 17 14 12 11 8 7 6 6 5 4 3 3 3 370 284 212 118 246

387 311 276 229 185 97 77 60 46 30 26 23 20 17 13 11 10 9 8 6 5 5 4 581 446 332 185 387

558 448 398 330 267 139 112 87 66 44 38 33 28 24 18 16 15 13 11 9 8 8 6 839 644 480 267 558

3.5 (2.0) 5.5 (2.6)

5 3

8 6

13 10

23 18

32 25

52 41

75 58

115 90

154 198 120 154

311 242

448 350

8.0 (3.2)

1

4

6

11

15

24

35

54

72

92

145

209

14 22 30 38 50 60 80 100 125 150 175 200 250

1 1 1 1 0 0 0 0 0 0 0 0 0

3 1 1 1 1 1 1 0 0 0 0 0 0

5 3 2 1 1 1 1 1 1 1 0 0 0

8 6 4 3 2 2 1 1 1 1 1 1 1

11 8 6 4 3 3 2 1 1 1 1 1 1

18 14 10 7 6 5 4 3 3 2 1 1 1

27 20 14 10 8 7 6 5 4 3 3 3 2

41 31 22 15 13 11 9 8 6 5 5 4 3

55 41 30 21 18 15 13 10 8 7 6 6 5

71 53 38 27 23 19 16 14 11 9 8 7 6

111 83 60 42 36 31 26 21 17 15 13 12 10

160 120 87 61 52 44 37 31 25 22 19 17 14


136


CONDUCTORS Type RHH*, RHW*, RHW-2*, TW, THW, THHW, THW-2 THHN, THWN, THWN-2



Z




20

25

32

40

50

65

80

0 0 0 0 13 9 6 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 12 9 6 3 2 1 1 1

0 0 0 0 22 16 10 6 4 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 22 16 11 6 4 3 1 1

0 0 0 0 36 26 17 9 7 4 3 1 1 1 1 1 1 1 1 1 0 0 0 0 0 35 26 18 10 7 5 3 2

1 0 0 0 63 46 29 16 12 7 5 4 3 2 1 1 1 1 1 1 1 1 0 0 0 61 44 32 18 13 9 6 4

1 1 1 0 85 62 39 22 16 10 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 83 60 43 25 17 12 8 6

1 1 1 1 140 102 64 37 27 16 11 8 7 6 5 4 3 3 2 2 1 1 1 1 1 136 99 71 41 29 20 14 9

1 1 1 1 200 146 92 53 38 23 17 12 10 8 7 6 5 4 3 3 2 1 1 1 1 194 142 102 58 41 29 20 14

3 2 2 1 309 225 142 82 59 36 26 19 16 13 11 9 7 6 5 5 4 3 3 3 1 300 219 157 90 64 44 31 21

4 5 3 4 3 4 2 3 412 531 301 387 189 244 109 140 79 101 48 62 34 44 25 33 21 27 18 23 15 19 12 16 10 13 8 11 7 10 7 8 5 7 4 6 4 5 4 5 3 4 400 515 292 376 209 269 120 154 85 110 59 77 41 53 28 37

8 12 7 10 7 10 5 8 833 1202 608 877 383 552 221 318 159 230 98 141 70 100 51 74 43 63 36 52 30 43 25 36 20 29 17 25 15 22 13 20 11 16 9 13 7 11 7 11 6 8 808 1166 590 851 423 610 242 350 172 249 120 174 83 120 57 83

1 1 0 0 15 10 6 4 3 1 1 1 9 7 5 3 1 1 1

1 1 1 1 26 18 11 7 5 3 1 1 15 12 9 5 3 2 1

1 1 1 1 42 30 18 11 8 5 3 2 25 19 14 8 6 4 3

3 3 2 1 73 52 32 20 14 9 6 5 44 33 25 14 10 7 5

5 4 3 2 100 71 43 27 19 13 8 6 59 45 34 19 14 10 7

8 6 5 4 164 116 71 45 31 22 13 10 98 75 56 31 23 16 12

11 9 8 6 234 166 102 64 45 31 19 15 140 107 80 44 33 24 17

18 14 12 10 361 256 157 99 69 48 29 23 216 165 123 68 51 37 26

24 19 16 13 482 342 209 132 93 64 39 31 288 221 164 91 68 49 35

48 40 33 27 974 691 423 267 188 129 78 63 581 446 332 185 137 99 70

137

90

100

30 25 21 17 621 440 269 170 120 82 50 40 370 284 212 118 87 63 45

125

150

69 57 47 39 1405 997 610 386 271 186 113 92 839 644 480 267 197 143 101


CONDUCTORS Type XHH, XHHW, XHHW-2



20

25

32

40

50

65

80

90

100

125

150

1 1 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 0 0 0 0 0 0 0 0 0

1 1 1 1 1 1 1 1 1 0 0 0 0 0

4 3 2 1 1 1 1 1 1 1 1 0 0 0

5 4 3 3 2 1 1 1 1 1 1 1 1 1

9 7 6 5 4 3 3 2 2 1 1 1 1 1

12 10 9 7 6 5 4 3 3 2 1 1 1 1

19 16 13 11 9 7 6 6 5 4 3 3 3 1

26 22 18 15 12 10 9 7 7 5 4 4 4 3

33 28 23 19 16 13 11 10 9 7 6 5 5 4

52 44 37 30 25 20 18 15 14 11 9 7 7 6

76 64 53 44 36 30 25 22 20 16 13 11 11 8



KF-2, KFF-2

KF-1, KFF-1

XF, XFF


15 8 7 11 9 7 19 14

20 15 12 19 15 12 33 25

1.25

11

20

2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

9 23 17 21 16 12 28 20 15 40 28 19 13 9 48 34 23 15 10 5 3

15 40 30 38 29 22 48 36 26 71 50 34 23 15 84 59 40 26 17 8 6

Raceway Size 25 24 20 31 25 20 54 40

(mm) 32 42 35 53 44 35 94 69

40 57 48 72 59 48 127 94

50 94 79 118 98 79 209 155

32

56

76

125

25 64 49 61 47 35 79 58 42 114 80 55 38 25 136 96 64 42 28 13 10

44 111 84 105 81 61 135 100 73 197 138 95 65 44 235 165 111 73 48 23 18

59 150 115 143 110 83 184 136 100 267 188 129 89 59 318 224 150 100 65 32 25

98 248 189 235 181 136 303 223 164 439 310 213 146 98 524 368 248 164 107 52 41


138

Power Cables & Wires Technical Manual Table A49 Maximum Number of Compact Conductors in Rigid Metal Conduit (Based on Table 9.1.1.1)


THHN, THWN, THWN-2

XHHW, XHHW-2


15 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0  2 1 1 1 1 1 0 0 0 0 0 0 0 0 00 0 3 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0

COMPACT CONDUCTORS Raceway Size (mm) 20 25 32 40 50 65 80 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0  5 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 5 4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0

7 5 4 3 1 1 1 1 1 1 1 1 1 0 0 0 0 0  8 5 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 9 6 5 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0

12 9 7 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0  13 8 6 4 4 3 2 1 1 1 1 1 1 1 1 1 0 15 11 8 6 4 4 3 2 1 1 1 1 1 1 1 1 1 0

16 12 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1  18 11 8 6 5 4 3 3 2 1 1 1 1 1 1 1 1 21 15 11 8 6 5 4 3 3 2 1 1 1 1 1 1 1 1

26 20 15 11 8 7 6 5 4 3 3 2 1 1 1 1 1 1  30 18 13 10 8 7 6 5 4 3 3 2 1 1 1 1 1 34 25 18 13 10 8 7 6 5 4 3 3 2 1 1 1 1 1

38 29 22 16 11 10 8 7 6 4 4 3 3 3 1 1 1 1  43 26 19 14 12 10 8 7 5 4 4 3 3 2 1 1 1 49 36 26 19 14 12 10 8 7 5 5 4 4 3 2 1 1 1

59 45 34 25 17 15 13 11 9 7 6 5 5 4 3 3 3 1  66 41 29 22 19 15 13 10 8 7 6 5 5 4 3 3 2 76 56 41 29 22 19 16 13 11 8 7 6 6 5 4 3 3 2

90

100

125

150

78 60 45 33 23 20 17 14 12 9 8 7 7 5 4 4 4 3  88 55 39 29 25 21 17 14 11 10 8 7 6 5 4 4 3 101 75 55 39 29 25 21 17 14 11 10 9 8 6 5 4 4 3

101 78 58 43 30 26 22 19 15 12 11 9 8 7 6 5 5 4  114 70 50 38 32 26 22 18 14 12 11 10 8 6 5 5 4 130 97 70 50 38 32 27 22 19 15 13 11 10 8 7 5 5 4

158 122 91 67 47 41 34 29 24 19 17 15 13 11 9 7 7 6  179 110 79 60 51 42 35 29 23 20 17 15 13 10 9 9 6 205 152 110 79 60 51 43 35 29 23 20 18 16 13 10 8 8 7

228 176 132 97 68 59 50 42 35 28 24 22 20 17 13 11 11 9  258 159 114 86 73 60 51 42 33 28 25 22 19 15 13 13 9 296 220 159 114 86 73 62 51 42 34 29 25 23 19 15 12 12 10


139

Power Cables & Wires Technical Manual Table A50 Maximum Number of Conductors and Fixture Wires in Rigid PVC Conduit, Schedule 80 (Based on Table 9.1.1.1) CONDUCTORS Type RH RHH, RHW, RHW2 RH, RHH, RHW, RHW-2

TW

RHH*, RHW*, RHW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, THHW, THW RHH*, RHW*, RHW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, TW, THW THHW, THW-2



20

25

32

40

50

65

80

90

100

125

150

2.0 (1.6) 3.5 (2.0) 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 2.0 (1.6)

4 3 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 5 3 1 4

8 6 5 4 3 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 11 9 6 3 8

13 10 9 7 6 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 20 15 11 6 13

23 19 17 14 11 6 4 3 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 35 27 20 11 23

32 26 23 19 15 8 6 5 4 2 1 1 1 1 1 1 1 1 1 0 0 0 0 49 38 28 15 32

55 44 39 32 26 13 11 8 6 4 3 3 3 2 1 1 1 1 1 1 1 1 1 82 63 47 26 55

79 63 56 46 37 19 16 12 9 6 5 4 4 3 2 2 1 1 1 1 1 1 1 118 91 67 37 79

123 99 88 73 59 31 24 19 14 9 8 7 6 5 4 3 3 3 2 1 1 1 1 185 142 106 59 123

166 133 118 98 79 41 33 26 20 13 11 10 8 7 5 5 4 4 3 3 2 2 1 250 192 143 79 166

215 173 153 127 103 54 43 33 25 17 15 13 11 9 7 6 5 5 4 3 3 3 2 324 248 185 103 215

341 274 243 202 163 85 68 53 41 27 23 20 17 15 11 10 9 8 7 6 5 5 4 514 394 294 163 341

490 394 349 290 234 122 98 77 58 38 33 29 25 21 16 14 13 12 10 8 7 7 5 736 565 421 234 490

3.5 (2.0) 5.5 (2.6)

3 2

6 5

10 8

19 15

26 20

44 34

63 49

99 77

133 104

173 135

274 214

394 307

8.0 (3.2)

1

3

5

9

12

20

29

46

62

81

128

184

14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0

3 3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0

7 5 3 2 1 1 1 1 1 1 1 1 1 0 0 0 0

9 7 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0

16 12 8 6 5 4 3 3 2 1 1 1 1 1 1 1 1

22 17 12 8 7 6 5 4 3 3 2 2 1 1 1 1 1

35 26 19 13 11 10 8 7 5 5 4 4 3 2 1 1 1

48 35 26 18 15 13 11 9 7 6 6 5 4 3 3 3 2

62 46 33 23 20 17 14 12 9 8 7 7 5 4 4 4 3

98 73 53 37 32 27 23 19 15 13 12 10 9 7 6 6 5

141 105 77 54 46 39 33 27 22 19 17 15 13 10 8 8 7


140


CONDUCTORS Type THHN, THWN, THWN-2



Z




20

25

32

40

50

65

80

90

100

125

9 6 4 2 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 6 4 2 1 1 1 1

17 12 7 4 3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 16 12 8 5 3 2 1 1

28 20 13 7 5 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 27 20 14 8 6 4 3 1

51 37 23 13 9 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 49 36 26 15 10 7 5 3

70 51 32 18 13 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0 68 50 36 20 14 10 7 5

118 86 54 31 22 14 10 7 6 5 4 3 3 2 1 1 1 1 1 1 1 115 84 60 34 24 17 12 8

170 124 78 45 32 20 14 10 9 7 6 5 4 3 3 3 2 1 1 1 1 164 120 86 49 35 24 17 11

265 193 122 70 51 31 22 16 14 11 9 8 6 5 5 4 3 3 2 2 1 257 188 135 77 55 38 26 18

358 261 164 95 68 42 30 22 18 15 13 10 8 7 6 6 5 4 3 3 2 347 253 182 104 74 52 35 25

464 338 213 123 89 54 39 29 24 20 17 14 11 9 8 7 6 5 4 4 3 450 328 235 135 96 67 46 32

736 1055 537 770 338 485 195 279 141 202 86 124 61 88 45 65 38 55 32 46 26 38 22 31 18 25 15 22 13 19 12 17 10 14 8 12 7 9 7 9 5 7 714 1024 521 747 374 536 214 307 152 218 106 153 73 105 51 73

0 0 0 0 10 7 4 3 2 1 1 0 6 5 3 1 1 1 1

1 1 1 0 19 14 8 5 4 2 1 1 11 9 6 3 2 1 1

1 1 1 1 33 23 14 9 6 4 2 2 20 15 11 6 4 3 2

3 2 1 1 59 42 26 16 11 8 5 4 35 27 20 11 8 6 4

4 3 2 1 82 58 36 22 16 11 6 5 49 38 28 15 11 8 6

7 5 4 4 138 98 60 38 26 18 11 9 82 63 47 26 19 14 10

10 8 6 5 198 141 86 54 38 26 16 13 118 91 67 37 28 20 14

15 12 10 8 310 220 135 85 60 41 25 20 185 142 106 59 43 31 22

20 17 14 11 418 297 182 115 81 55 33 27 250 192 143 79 59 42 30

27 22 18 15 542 385 235 149 104 72 43 35 324 248 185 103 76 55 39

42 61 35 50 29 41 24 34 860 1233 610 875 374 536 236 339 166 238 114 164 69 99 56 80 514 736 394 565 294 421 163 234 121 173 87 125 62 89

141

150

Power Cables & Wires Technical Manual Table A50 Continued CONDUCTORS Type XHH, XHHW, XHHW-2



20

25

32

40

50

65

80

90

100

125

150

0 0 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 1 1 0 0 0 0 0 0 0

3 2 1 1 1 1 1 1 1 1 0 0 0 0

4 3 3 2 1 1 1 1 1 1 1 1 1 0

7 6 5 4 3 3 2 1 1 1 1 1 1 1

10 9 7 6 5 4 3 3 3 2 1 1 1 1

16 14 11 9 8 6 5 5 4 3 3 2 2 1

22 19 16 13 11 9 7 6 6 5 4 3 3 2

29 24 20 17 14 11 10 8 7 6 5 4 4 3

46 39 32 27 22 18 15 14 12 10 8 6 6 5

66 56 46 38 32 26 22 20 17 14 11 9 9 7



KF-2, KFF-2

KF-1, KFF-1

XF, XFF


15 6 5 7 6 5 13 10

20 11 9 14 11 9 25 18

1.25

8

15

2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

6 16 12 15 11 8 19 14 10 28 19 13 9 6 33 23 16 10 7 3 2

11 29 22 28 22 16 36 27 19 53 37 25 17 11 63 44 29 19 13 6 5

Raceway Size 25 19 16 24 20 16 42 31

(mm) 32 34 28 43 35 28 76 56

40 47 39 59 49 39 105 77

50 79 67 100 82 67 177 130

25

45

62

105

20 50 38 47 36 27 61 45 33 88 62 43 29 20 106 74 50 33 21 10 8

35 90 68 85 66 49 110 81 59 159 112 77 53 35 190 133 90 59 39 19 15

49 124 95 118 91 68 152 112 82 220 155 107 73 49 263 185 124 82 54 26 20

82 209 159 198 153 115 255 188 138 371 261 179 123 82 442 310 209 138 90 44 34


142

Power Cables & Wires Technical Manual Table A51 Maximum Number of Compact Conductors in Rigid PVC Conduit, Schedule 80 (Based on Table 9.1.1.1)


THHN, THWN, THWN-2

XHHW, XHHW-2


15

8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0  1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0


5 4 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0  6 3 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0 7 5 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 0

9 7 5 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0  11 6 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0 12 9 6 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0

13 10 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 0  15 9 6 5 4 3 3 2 1 1 1 1 1 1 1 1 0 17 13 9 6 5 4 3 3 2 1 1 1 1 1 1 1 1 0

22 17 13 9 6 6 5 4 3 2 2 1 1 1 1 1 1 1  25 15 11 8 7 6 5 4 3 3 2 1 1 1 1 1 1 29 21 15 11 8 7 6 5 4 3 3 2 1 1 1 1 1 1

32 25 18 13 9 8 7 6 5 4 3 3 3 2 1 1 1 1  36 22 16 12 10 8 7 6 4 4 3 3 2 1 1 1 1 42 31 22 16 12 10 8 7 6 5 4 3 3 2 1 1 1 1

50 39 29 21 15 13 11 9 8 6 5 5 4 3 3 2 2 1  57 35 25 19 16 13 11 9 7 6 5 5 4 3 3 3 1 65 48 35 25 19 16 13 11 9 7 6 5 5 4 3 2 2 1

90

100

125

150

68 52 39 29 20 17 15 12 10 8 7 6 6 5 4 3 3 2  77 47 34 25 22 18 15 12 10 8 7 6 5 4 4 4 3 88 65 47 34 25 22 18 15 12 10 8 7 7 5 4 3 3 3

88 68 51 37 26 23 19 16 13 11 9 8 7 6 5 4 4 3  99 61 44 33 28 23 19 16 12 11 9 8 7 6 5 5 3 114 85 61 44 33 28 24 19 16 13 11 10 9 7 6 5 5 3

140 108 81 60 42 36 30 26 22 17 15 13 12 10 8 7 7 5  158 98 70 53 45 37 31 25 20 17 15 13 11 9 8 8 5 181 134 98 70 53 45 38 31 26 21 17 15 14 11 9 7 7 6

200 155 116 85 60 52 44 37 31 25 21 19 17 14 12 10 10 8  226 140 100 75 64 53 44 37 29 25 22 19 16 13 11 11 8 260 193 140 100 75 64 54 44 37 30 25 22 20 17 13 11 11 8


143

Power Cables & Wires Technical Manual Table A52 Maximum Number of Conductors and Fixture Wires in Rigid PVC Conduit, Schedule 40 and HDPE Conduit (Based on Table 9.1.1.1) CONDUCTORS Type RH RHH, RHW, RHW2 RH, RHH, RHW, RHW-2

TW

RHH*, RHW*, RHW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, THHW, THW RHH*, RHW*, RHW-2*, THW, THHW, THW-2 RHH*, RHW*, RHW-2*, TW, THW, THHN, THW-2



20

25

32

40

50

65

80

90

100

125

150

2.0 (1.6) 3.5 (2.0) 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 2.0 (1.6)

5 4 4 3 2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 6 4 2 5

9 8 7 5 4 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 14 11 8 4 9

16 12 11 9 7 4 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 24 18 13 7 16

28 22 20 16 13 7 5 4 3 1 1 1 1 1 1 1 1 1 0 0 0 0 0 42 32 24 13 28

38 30 27 22 18 9 7 6 4 3 2 1 1 1 1 1 1 1 1 1 0 0 0 57 44 32 18 38

63 50 45 37 30 15 12 10 7 5 4 3 3 2 1 1 1 1 1 1 1 1 1 94 72 54 30 63

90 72 64 53 43 22 18 14 10 7 6 5 4 4 3 2 2 1 1 1 1 1 1 135 103 77 43 90

139 112 99 82 66 35 28 22 16 11 9 8 7 6 4 4 3 3 3 2 1 1 1 209 160 119 66 139

186 150 133 110 89 46 37 29 22 14 13 11 9 8 6 5 5 4 4 3 2 2 1 280 215 160 89 186

240 193 171 142 115 60 48 37 28 19 16 14 12 10 8 7 6 6 5 4 3 3 3 361 277 206 115 240

378 304 269 224 181 94 76 59 45 29 26 22 19 16 12 11 10 9 8 6 5 5 4 568 436 325 181 378

546 439 390 323 261 137 109 85 65 43 37 32 28 24 18 16 14 13 11 9 8 8 6 822 631 470 261 546

3.5 (2.0) 5.5 (2.6)

4 3

8 6

12 10

22 17

30 24

50 39

72 56

112 87

150 117

193 150

304 237

439 343

8.0 (3.2)

1

3

6

10

14

23

33

52

70

90

142

205

14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0

4 3 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0

8 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0

11 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0

18 13 10 7 6 5 4 3 3 2 1 1 1 1 1 1 1

26 19 14 10 8 7 6 5 4 3 3 3 2 1 1 1 1

40 30 22 15 13 11 9 8 6 5 5 4 3 3 2 2 1

53 40 29 20 17 15 12 10 8 7 6 6 5 4 3 3 2

69 51 37 26 22 19 16 13 11 9 8 7 6 5 4 4 3

109 81 59 41 35 30 25 21 17 15 13 12 10 8 6 6 5

157 117 85 60 51 43 36 30 25 21 19 17 14 11 10 10 7


144




Z




20

25

32

40

50

65

80

90

100

125

150

11 8 5 3 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 11 8 6 3 2 1 1 1

21 15 9 5 4 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 20 15 10 6 4 3 1 1

34 25 15 9 6 4 3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 33 24 17 10 7 5 3 2

60 43 27 16 11 7 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0 58 42 30 17 12 8 6 4

82 59 37 21 15 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 0 79 58 41 24 17 12 8 5

135 99 62 36 26 16 11 8 7 6 5 4 3 3 2 1 1 1 1 1 1 131 96 69 39 28 19 13 9

193 141 89 51 37 22 16 12 10 8 7 6 4 4 3 3 2 1 1 1 1 188 137 98 56 40 28 19 13

299 218 137 79 57 35 25 18 15 13 11 9 7 6 5 5 4 3 2 2 1 290 212 152 87 62 43 30 20

401 293 184 106 77 47 33 25 21 17 14 12 10 8 7 6 5 4 3 3 3 389 284 204 117 83 58 40 28

517 377 238 137 99 61 43 32 37 22 18 15 12 11 9 8 7 5 4 4 3 502 366 263 150 107 75 51 36

815 594 374 216 156 96 68 50 42 35 29 24 20 17 15 13 11 9 7 7 6 790 577 414 237 169 118 81 56

1178 859 541 312 225 138 98 73 61 51 42 35 28 24 21 19 16 13 11 11 8 1142 834 598 343 244 170 117 81

1 0 0 0 13 9 6 3 2 1 1 1 8 6 4 2 1 1 1

1 1 1 1 24 17 10 6 4 3 1 1 14 11 8 4 3 2 1

1 1 1 1 40 28 17 11 7 5 3 2 24 18 13 7 5 4 3

3 3 2 1 70 49 30 19 13 9 5 4 42 32 24 13 10 7 5

4 4 3 2 95 68 41 26 18 12 7 6 57 44 32 18 13 9 7

8 6 5 4 158 112 69 43 30 21 12 10 94 72 54 30 22 16 11

11 9 7 6 226 160 98 62 43 30 18 14 135 103 77 43 32 23 16

17 14 12 9 350 248 152 96 67 46 28 23 209 160 119 66 49 35 25

23 19 16 13 469 333 204 129 90 62 38 30 280 215 160 89 66 48 34

30 24 20 16 605 429 263 166 116 80 49 39 361 277 206 115 85 61 44

47 68 39 56 32 46 26 38 952 1376 675 976 414 598 261 378 184 265 126 183 77 111 62 90 568 822 436 631 325 470 181 261 134 193 97 140 69 99

145




20

25

32

40

50

65

80

90

100

125

150

1 1 0 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 0 0 0 0 0 0 0 0 0

1 1 1 1 1 1 1 1 0 0 0 0 0 0

3 3 2 1 1 1 1 1 1 1 1 0 0 0

5 4 3 3 2 1 1 1 1 1 1 1 1 0

8 7 6 5 4 3 3 2 1 1 1 1 1 1

12 10 8 7 6 5 4 3 3 2 1 1 1 1

19 16 13 11 9 7 6 5 5 4 3 2 2 1

25 21 17 14 12 10 8 7 6 5 4 3 3 3

32 27 23 19 15 13 11 9 8 7 5 4 4 3

51 43 36 30 24 20 17 15 13 11 9 7 7 6

74 62 52 43 35 29 25 22 19 16 13 11 11 8



KF-2, KFF-2

KF-1, KFF-1

XF, XFF


15 8 6 10 8 6 17 13

20 14 12 17 14 12 31 23

1.25

10

18

2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

8 20 16 19 15 11 25 18 13 36 26 17 12 8 43 30 20 13 9 4 3

14 37 28 35 27 20 45 33 24 65 46 31 22 14 78 55 37 24 16 8 6

Raceway Size 25 23 19 29 24 19 51 38

(mm) 32 40 33 50 42 33 89 66

40 54 46 69 57 46 122 90

50 90 76 114 94 76 202 149

30

53

73

120

24 60 46 57 44 33 74 54 40 107 75 52 35 24 128 90 60 40 26 12 10

42 105 80 100 77 58 129 95 70 187 132 90 62 42 223 157 105 70 45 22 17

57 144 110 137 106 79 176 130 95 256 180 124 85 57 305 214 144 95 62 30 24

94 239 183 227 175 131 292 216 158 424 299 205 141 94 506 355 239 158 103 50 39


146

Power Cables & Wires Technical Manual Table A53 Maximum Number of Compact Conductors in Rigid PVC Conduit, Schedule 40 and HDPE Conduit (Based on Table 9.1.1.1)


THHN, THWN, THWN-2

XHHW, XHHW-2


15

8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0  2 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0


6 5 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 0  7 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0 8 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 0

11 9 6 5 3 3 2 1 1 1 1 1 1 1 1 0 0 0  13 8 5 4 3 3 2 1 1 1 1 1 1 1 1 1 0 14 11 8 5 4 3 3 2 1 1 1 1 1 1 1 1 1 0

15 12 9 6 4 4 3 3 2 1 1 1 1 1 1 1 1 1  17 11 8 6 5 4 3 3 1 1 1 1 1 1 1 1 1 20 15 11 8 6 5 4 3 3 1 1 1 1 1 1 1 1 1

26 20 15 11 7 6 5 5 4 3 2 2 1 1 1 1 1 1  29 18 13 9 8 7 5 4 3 3 3 2 1 1 1 1 1 33 25 18 13 9 8 7 5 5 4 3 3 2 1 1 1 1 1

37 28 21 15 11 9 8 7 5 4 4 3 3 2 1 1 1 1  41 25 18 14 12 9 8 6 5 4 4 3 3 2 1 1 1 47 35 25 18 14 12 10 8 7 5 4 4 3 3 2 1 1 1

57 44 33 24 17 15 12 10 9 7 6 5 5 4 3 2 2 1  64 40 28 21 18 15 12 10 8 7 6 5 4 4 3 3 2 73 55 40 28 21 18 15 12 10 8 7 6 5 4 4 3 3 2

90

100

125

150

76 59 44 32 23 20 16 14 12 9 8 7 6 5 4 3 3 3  86 53 38 29 24 20 17 14 11 9 8 7 6 5 4 4 3 99 73 53 38 29 24 20 17 14 11 9 8 7 6 5 4 4 3

98 76 57 42 29 25 21 18 15 12 10 9 8 7 5 5 5 4  111 68 49 37 31 26 22 18 14 12 10 9 8 6 5 5 4 127 94 68 49 37 31 26 22 18 14 12 11 10 8 6 5 5 4

155 119 89 66 46 40 34 29 24 19 16 15 13 11 9 7 7 6  175 108 77 58 49 41 34 28 22 19 17 15 13 10 8 8 6 200 149 108 77 58 49 42 34 29 23 19 17 15 13 10 8 8 6

224 173 129 95 67 58 49 42 35 27 24 21 19 16 13 11 11 9  253 156 112 84 72 59 50 41 32 28 24 22 18 15 12 12 9 290 215 156 112 84 72 60 50 42 33 28 25 22 18 15 12 12 9


147

Power Cables & Wires Technical Manual Table A54 Maximum Number of Conductors and Fixture Wires in Type A, Rigid PVC Conduit (Based on Table 9.1.1.1)


TW


Conductor Size [mm2 (mm dia.)] 2.0 (1.6) 3.5 (2.0) 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0(3.2) 2.0 (1.6)


20

25

32

40

50

65

80

90

100

7 6 5 4 3 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11 8 6 3 7

12 10 9 7 6 3 2 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 18 14 10 6 12

20 16 15 12 10 5 4 3 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0 31 24 18 10 20

34 27 24 20 16 8 6 5 4 2 2 1 1 1 1 1 1 1 1 0 0 0 0 51 39 29 16 34

44 35 31 26 21 11 9 7 5 3 3 2 1 1 1 1 1 1 1 1 1 1 0 67 51 38 21 44

70 56 49 41 33 17 14 11 8 5 5 4 3 3 1 1 1 1 1 1 1 1 1 105 80 60 33 70

104 84 74 61 50 26 21 16 12 8 7 6 5 4 3 3 2 2 1 1 1 1 1 157 120 89 50 104

157 126 112 93 75 39 31 24 18 12 10 9 8 7 5 4 4 4 3 2 1 1 1 235 181 135 75 157

204 164 146 121 98 51 41 32 24 16 14 12 10 9 7 6 5 5 4 3 3 3 2 307 236 176 98 204

262 211 187 155 125 65 52 41 31 20 18 15 13 11 8 7 7 6 5 4 4 4 3 395 303 226 125 262

3.5 (2.0) 5.5 (2.6)

6 4

10 8

16 13

27 21

35 28

56 44

84 65

126 98

164 128

211 165

8.0 (3.2)

2

4

8

12

16

26

39

59

77

98

14 22 30 38 50 60 80 100 125 150 175 200 250

1 1 1 1 1 0 0 0 0 0 0 0 0

3 2 1 1 1 1 1 1 0 0 0 0 0

6 4 3 1 1 1 1 1 1 1 1 1 0

9 7 5 3 3 2 1 1 1 1 1 1 1

13 9 7 5 4 3 3 2 1 1 1 1 1

20 15 11 7 6 5 4 4 3 2 2 1 1

30 22 16 11 10 8 7 6 4 4 3 3 2

45 33 24 17 14 12 10 9 7 6 5 5 4

59 44 32 22 19 16 13 11 9 8 7 6 5

75 56 41 29 24 21 17 14 12 10 9 8 7


148





Z




20

25

32

40

50

65

80

90

100

0 0 0 0 16 11 7 4 3 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 15 11 8 4 3 1 1 1

0 0 0 0 27 19 12 7 5 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 26 19 13 8 5 4 2 1

0 0 0 0 44 32 20 12 8 5 3 2 2 1 1 1 1 1 1 1 1 0 0 0 0 43 31 22 13 9 6 4 3

1 1 1 0 73 53 33 19 14 8 6 4 4 3 2 1 1 1 1 1 1 1 1 1 0 70 51 37 21 15 10 7 5

1 1 1 1 96 70 44 25 18 11 8 6 5 4 3 3 2 1 1 1 1 1 1 1 1 93 68 48 28 20 14 9 6

1 1 1 1 150 109 69 40 28 17 12 9 8 6 5 4 3 3 2 2 1 1 1 1 1 146 106 76 44 31 21 15 10

1 1 1 1 225 164 103 59 43 26 19 14 11 10 8 6 5 4 4 3 3 2 1 1 1 218 159 114 65 46 32 22 15

3 3 3 1 338 246 155 89 64 39 28 21 17 14 12 10 8 7 6 5 4 3 3 3 2 327 239 171 98 70 49 33 23

4 3 3 3 441 321 202 117 84 52 37 27 23 19 16 13 10 9 8 7 6 5 4 4 3 427 312 224 128 91 64 44 30

5 4 4 3 566 412 260 150 108 66 47 35 29 24 20 17 14 12 10 9 7 6 5 5 4 549 400 287 165 117 82 56 39

1 1 1 0 18 13 8 5 3 2 1 1 11 8 6 3 2 1 1

1 1 1 1 31 22 13 8 6 4 2 1 18 14 10 6 4 3 1

2 1 1 1 52 37 22 14 10 7 4 3 31 24 18 10 7 5 3

4 3 3 2 85 60 37 23 16 11 7 5 51 39 29 16 12 8 6

5 4 3 3 112 79 48 30 21 15 9 7 67 51 38 21 15 11 8

8 7 6 5 175 124 76 48 34 23 14 11 105 80 60 33 24 18 12

13 10 9 7 263 186 114 72 50 35 21 17 157 120 89 50 37 26 19

19 16 13 11 395 280 171 108 76 52 32 26 235 181 135 75 55 40 28

25 21 17 14 515 365 224 141 99 68 41 33 307 236 176 98 75 52 37

32 27 22 18 661 469 287 181 127 88 53 43 395 303 226 125 93 67 48


149





20

25

32

40

50

65

80

90

100

1 1 1 0 0 0 0 0 0 0 0 0 0 0

1 1 1 1 1 1 0 0 0 0 0 0 0 0

3 2 1 1 1 1 1 1 1 1 0 0 0 0

4 4 3 2 1 1 1 1 1 1 1 1 1 0

6 5 4 3 3 2 1 1 1 1 1 1 1 1

9 8 6 5 4 3 3 3 2 1 1 1 1 1

14 12 10 8 7 5 5 4 3 3 2 1 1 1

21 18 15 12 10 8 7 6 5 4 3 3 3 2

28 23 19 16 13 11 9 8 7 6 5 4 4 3

35 30 25 20 17 14 12 10 9 8 6 5 5 4



KF-2, KFF-2

KF-1, KFF-1

XF, XFF

Raceway Size (mm) 25 32 30 48 25 41 37 61 31 51 25 41 66 108 49 80


15 10 9 13 11 9 23 17

20 18 15 22 18 15 40 29

1.25

14

24

39

2.0 0.75 1.25 0.75 1.25 2.0 0.75 1.25 2.0 0.75 1.25 2.0 3.5 5.5 0.75 1.25 2.0 3.5 5.5 3.5 5.5

11 28 21 26 20 15 34 25 18 49 35 24 16 11 59 41 28 18 12 6 4

18 47 36 45 35 26 58 42 31 84 59 40 28 18 100 70 47 31 20 10 8

31 79 60 74 58 43 96 71 52 140 98 67 46 31 167 117 79 52 34 16 13

40 64 54 81 67 54 143 105

50 100 85 127 105 85 224 165

65

85

134

51 128 98 122 94 70 157 116 85 228 160 110 76 51 272 191 128 85 55 27 21

67 169 129 160 124 93 206 152 112 300 211 145 100 67 357 251 169 112 73 35 28

105 265 202 251 194 146 324 239 175 470 331 228 157 105 561 394 265 175 115 56 44


150

Power Cables & Wires Technical Manual Table A55 Maximum Number of Compact Conductors in Type A, Rigid PVC Conduit (Based on Table 9.1.1.1, Chapter 9)


THHN, THWN, THWN-2

XHHW, XHHW-2


15

8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

3 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0  3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 4 3 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0


8 6 5 3 2 1 1 1 1 1 1 1 1 1 0 0 0 0  9 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0 11 8 6 4 3 2 1 1 1 1 1 1 1 1 0 0 0 0

14 10 8 6 4 3 3 2 1 1 1 1 1 1 1 1 1 0  15 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 0 18 13 9 7 5 4 3 3 2 1 1 1 1 1 1 1 1 0

18 14 10 7 5 4 4 3 3 1 1 1 1 1 1 1 1 1  20 12 9 7 6 5 4 3 2 1 1 1 1 1 1 1 1 23 17 12 9 7 6 5 4 3 2 1 1 1 1 1 1 1 1

28 22 16 12 8 7 6 5 4 3 3 2 2 1 1 1 1 1  32 20 14 10 9 7 6 5 4 3 3 2 2 1 1 1 1 37 27 20 14 10 9 7 6 5 4 3 3 3 2 1 1 1 1

42 33 24 18 13 11 9 8 6 5 4 4 3 3 2 1 1 1  48 30 21 16 13 11 9 8 6 5 4 4 3 3 2 2 1 55 41 30 21 16 13 11 9 8 6 5 5 4 3 3 2 2 1

80

90

100

64 49 37 27 19 16 14 12 10 8 7 6 5 4 3 3 3 2  72 45 32 24 20 17 14 11 9 8 7 6 5 4 3 3 2 83 62 45 32 24 20 17 14 12 9 8 7 6 5 4 3 3 2

84 65 48 36 25 21 18 15 13 10 9 8 7 6 5 4 4 3  94 58 42 31 27 22 18 15 12 10 9 8 7 5 4 4 3 108 80 58 42 31 27 22 18 15 12 10 9 8 7 5 4 4 3

107 83 62 46 32 28 23 20 17 13 11 10 9 8 6 5 5 4  121 75 54 40 34 28 24 19 15 13 11 10 9 7 6 6 4 139 103 75 54 40 34 29 24 20 16 13 12 11 9 7 6 6 4


151

Power Cables & Wires Technical Manual Table A56 Maximum Number of Conductors in Type EB, PVC Conduit (Based on Table 9.1.1.1) CONDUCTORS Type RH RHH, RHW, RHW-2 RH, RHH, RHW, RHW-2

TW


Raceway Size (mm) 90 100 217 276 175 222 155 197 128 163 104 132 54 69 43 55 34 43 26 33 17 21 15 19 13 16 11 14 9 12 7 9 6 8 5 7 5 6 4 5 3 4 3 4 2 3 2 3 327 415 251 319 187 238 104 132 217 276


50 74 59 53 44 35 18 15 11 9 6 5 4 4 3 2 1 1 1 1 1 1 1 1 111 85 63 35 74

80 166 134 119 98 79 41 33 26 20 13 11 10 8 7 5 5 4 4 3 3 2 1 1 250 192 143 79 166

3.5 (2.0) 5.5 (2.6)

59 46

134 104

175 136

8.0 (3.2)

28

62

14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

21 16 11 8 7 6 5 4 3 3 2 2 1 1 1 1 1

48 36 26 18 15 13 11 9 7 6 6 5 4 3 3 2 2

125 424 341 303 251 203 106 85 66 50 33 29 25 22 18 14 12 11 10 9 7 6 5 5 638 490 365 203 424

150 603 485 430 357 288 151 121 94 72 47 41 36 31 26 20 17 16 14 12 10 9 7 7 907 696 519 288 603

222 173

341 266

485 378

81

104

159

227

62 46 34 24 20 17 14 12 10 8 7 7 5 4 4 3 3

79 59 43 30 26 22 18 15 12 11 9 8 7 6 5 4 4

122 91 66 46 40 34 28 24 19 17 15 13 11 9 7 6 6

173 129 94 66 56 48 40 34 27 24 21 19 16 13 11 8 8


152




Z


Conductor Size [mm2 (mm dia.)] 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38

50 159 116 73 42 30 19 13 10 8 7 5 4 4 3 3 2 1 1 1 1 1 155 113 81 46 33 23 16 11

80 359 262 165 95 68 42 30 22 18 15 13 10 8 7 6 6 5 4 3 2 2 348 254 182 104 74 52 36 25

50 60 80 100 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30 38 2.0 (1.6) 3.5 (2.0) 5.5 (2.6) 8.0 (3.2) 14 22 30

9 7 6 5 186 132 81 51 36 24 15 12 111 85 63 35 26 19 13

20 17 14 11 419 297 182 115 81 55 34 27 250 192 143 79 59 42 30

Raceway Size (mm) 90 100 468 595 342 434 215 274 124 158 89 114 55 70 39 50 29 37 24 31 20 26 17 21 14 18 11 14 10 12 8 11 7 10 6 8 5 6 4 5 3 4 3 4 454 578 332 422 238 302 136 173 97 123 68 86 46 59 32 41 27 22 18 15 547 388 238 150 105 72 44 36 327 251 187 104 77 56 39

34 28 23 19 696 494 302 191 134 92 56 45 415 319 238 132 98 71 50

125 915 667 420 242 175 107 76 57 48 40 33 27 22 19 17 15 12 10 8 6 6 888 648 465 266 189 132 91 63

150 1300 948 597 344 248 153 109 80 68 56 47 39 31 27 24 21 18 14 12 9 9 1261 920 660 378 269 188 129 90

53 43 36 29 1069 759 465 294 206 142 86 70 638 490 365 203 150 109 77

75 62 51 42 1519 1078 660 417 293 201 122 99 907 696 519 288 213 155 110


153



50 10 8 7 6 5 4 3 3 2 1 1 1 1 1

80 22 19 16 13 11 9 7 6 6 5 4 3 2 2

Raceway Size 90 29 25 20 17 14 11 10 9 8 6 5 4 3 3

(mm) 100 37 31 26 22 18 15 12 11 10 8 6 5 4 4

125 58 48 40 33 27 22 19 17 15 12 10 8 6 6

150 82 69 57 47 39 32 28 24 22 18 14 12 9 9


154

Power Cables & Wires Technical Manual Table A57 Maximum Number of Compact Conductors in Type EB, PVC Conduit (Based on Table 9.1.1.1) CONDUCTORS Type THW, THW2, THHW

THHN, THWN, THWN-2

XHHW, XHHW-2


50

80

8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500 8.0 14 22 30 38 50 60 80 100 125 150 175 200 250 325 375 400 500

30 23 17 13 9 8 6 5 4 3 3 3 2 1 1 1 1 1  34 21 15 11 9 8 6 5 4 4 3 3 2 1 1 1 1 39 29 21 15 11 9 8 6 5 4 4 3 3 2 1 1 1 1

68 52 39 29 20 17 15 12 10 8 7 6 6 5 4 3 2 2  77 47 34 25 22 18 15 12 10 8 7 6 5 4 4 3 3 88 65 47 34 25 22 18 15 12 10 8 7 7 5 4 3 3 3

Raceway Size (mm) 90 100 89 69 51 38 26 23 19 16 14 11 9 8 7 6 5 4 3 3  100 62 44 33 28 23 20 16 13 11 9 8 7 6 5 3 3 115 85 62 44 33 28 24 20 16 13 11 10 9 7 6 5 4 4

113 87 65 48 34 29 24 21 17 14 12 11 10 8 6 5 4 4  128 79 57 42 36 30 25 20 16 14 12 11 9 7 6 4 4 146 109 79 57 42 36 30 25 21 17 14 12 11 9 7 6 5 5

125

150

174 134 100 74 52 45 38 32 27 21 19 17 15 12 10 8 7 7  196 121 87 65 56 46 38 32 25 22 19 17 14 11 9 7 7 225 167 121 87 65 56 47 38 32 26 22 19 17 14 11 9 7 7

247 191 143 105 74 64 54 46 38 30 26 24 21 18 14 12 9 9  279 172 124 93 79 65 55 45 35 31 27 24 20 16 14 10 10 320 238 172 124 93 79 67 55 46 37 31 28 25 20 16 13 10 10


155


156


ANNEX B Conductor Application and Insulation

157


158

Table B1. Conductor Application and Insulations Trade Name

Mineral insulation (metal sheathed)

159

Moisture-, heat-, and oil-resistant thermoplastic

FEP or FEPB

200°C

MI

MTW

90°C

Material

Dry and damp locations

Dry locations — special applicationsb

Dry and wet locations

Flourinated ethylene Propylene Flourinated ethylene Propylene Magnesium oxide

b

For special applications

60°C

Machine tool wiring in wet locations as permitted in NFPA 79 see Article 6.70) Machine tool wiring in dry locations as permitted in NFPA 79 (see Article 6.70)

Flame-retardant moisture-, heat-, and oil-resistant thermoplastic

For underground service conductors, or by special permission Dry and damp locations

Paper

85°C

PFA

Application Provisions

250°C

90°C

Paper

Perfluoroalkoxy

Maximum Operating Temperatur e 90°C

90°C 200°C


Perfluoro-alkoxy

Insulation Conductor Area (mm2)

Thickness (mm)

Outer Coveringa

2.0 – 5.5

0.50

None

8.0 – 30 2.0 – 8.0

0.80 0.40

Glass braid

14 – 30

0.40 c

0.75 – 1.25 1.25 – 5.5 5.6 – 22 23 – 250 0.65 – 3.5 5.5 8.0 14 22 – 30 38 – 100 101 – 250 251 – 500

0.58 0.90 1.30 1.40 (a) 0.80 0.80 1.20 1.60 1.60 2.00 2.40 2.80

(b) 0.40 0.50 0.80 0.80 1.00 1.30 1.60 1.80

Other suitable braid material Copper or alloy steel

(a) None (b) Nylon jacket or equivalent

Lead sheath

2.0 – 5.5 8.0 – 30 38 – 100

0.50 0.80 1.20

None


Fluorinated ethylene propylene

Type Letter

PFAH

Dry locations only. Only for leads Within apparatus or within raceways connected to apparatus (nickel or nickel-coated copper only)

Perfluoroalkoxy

2.0 – 5.5 8.0 – 30 38 –100

0.50 0.80 1.20

Thermoset

RH

75°C


Flame-retardant thermoset

Thermoset

RHH

90°C


2.0 – 3.5d 5.5 8.0 – 30 38 –100 101 – 250 251 – 500 501 – 1 000 For 601 – 2000 Volts, see Table 3.10.1.62

0.80 1.20 1.60 2.00 2.40 2.80 3.20

Moisture resistant, flame-retardant, nonmetallic covering1

Moistureresistant thermoset

RHWe

75°C

Dry and wet locations Where over 2 000 volts Insulation, shall be Ozone resistant

Flame-retardant, moisture-resistant thermoset

2.0 – 5.5dd 8.0 – 30 38 –100 101 – 250 251 – 500 501 – 1 000 For 601 – 2000 Volts, see Table 3.10.1.62

1.20 1.60 2.00 2.40 2.80 3.20

Moisture resistant, flame-retardant, nonmetallic covering5

160

250°C

a

Some insulations do not require an outer covering. Where Design conditions require maximum conductor operating temperature above 90 oC For signaling circuits permitting 300-volts insulation. d For size 2.0 – 3.5 mm2, RHH insulation shall be 1.20 mm thickness. e Listed wire type designated with the suffix “-2”, such as RHW-2, shall be permitted to be used at continuous 90 oC operating temperature, wet or dry. f Some rubber insulations do not require an outer covering. b c

None


Perfluoroalkoxy

Table B1. (Continued) Trade Name

Type Letter

Maximum Operating Temperature


Insulation Materials

90°C


Flame-retardant, moisture-resistant thermoset

Silicon

SA

90°C


200°C

For special applicationb

Silicon rubber

Thermoset

SIS

90°C

Switchboard wiring only


Thermoplastic and fibrous outer braid

TBS

90°C

Switchboard Wiring only

Thermoplastic

Extended polytetrafluoro -ethylene

TFE

250°C

Dry locations only. Only for leads within apparatus or within raceways connected to apparatus,or as open wiring (Nickel or nickelcoated copper only)

Extruded Polytetrafluoroethylene

Thickness (mm) 1.20 1.60 2.00 2.40 2.80 3.20

1.20 1.60 2.00 2.40 2.80 3.20 0.80 1.20 2.40 0.80 1.20 1.60 2.00 0.50 0.80 1.20

Outer Coveringa Moistureresistant, flame-retardant, nonmetallic coveringf

Glass or other suitable braid material

None

Flame-retardant, nonmetallic covering None


RHW-2

161


Conductor Area (mm2) 2.0 – 5.5 8.0 – 30 38 – 100 101 – 250 251 – 500 501 – 1 000 For 601 – 2 000 Volts, see Table 3.10.1.62 2.0 – 5.5 8.0 – 30 38 – 100 101 – 250 251 – 500 501 – 1 000 2.0 – 5.5 8.0 – 30 38 – 100 2.0 – 5.5 8.0 14 – 30 38 – 100 2.0 – 5.5 8.0 – 30 38 – 100

90°C

Dry and damp location

Flame- retardant, heat-resistant thermoplastic

Moisture-and heat-resistant thermoplastic

THHW

75°C

Wet location

90°C

Dry location

Flame-retardant, moisture- and heatresistant thermoplastic


THWc

75°C


90°C


THWNe

Special applications within electric discharge lighting equip. Limited to 1 000 open –circuit volts or less (size 2.0 – 8.0 mm2 only as permitted in Section 4.10.6.10) Dry and wet locations

a

75°C



2.0 – 3.5 5.5 8.0 – 14 22 – 30 38 – 100 125 – 250 251 – 500 2.0 – 5.5 8.0 14 – 30 38 – 100 101 – 250 251 – 500 2.0 – 5.5 8.0 14 – 30 38 – 100 101 –250 251 – 500 501 – 1 000

0.40 0.50 0.80 1.00 1.30 1.60 1.80 0.80 1.20 1.60 2.00 2.40 2.80 0.80 1.20 1.60 2.00 2.40 2.80 3.20

Nylon jacket or equivalent

2.0 – 3.5 5.5 8.0 – 14 22 – 30 38 – 100 125 – 250 251 – 500

0.40 0.50 0.80 1.00 1.30 1.60 1.80

Nylon jacket or equivalent

None

None

Some insulations do not require an outer covering Where design conditions require maximum conductor operating temperature above 90°C e Listed wire type designated with the suffix “-2”, such as RHW-2, shall be permitted to be used at a continuous 90°C operating temperature, wet or dry. f Some rubber insulations do not require an outer covering.

b


THHN

162

Heat-resistant thermoplastic

Table B1. (Continued) Trade Name

Type Letter

Maximum Operating Temperature


Insulation Materials

60 C


Flame-retardant, Moisture-resistant Thermoplastic

Underground feeder and branch-circuit cable —single conductor (For Type UF cable employing more than one conductor, see Article 3.39.) Underground service-entrance Cable — single conductor (For Type USE cable employing more than one conductor, see Article 3.38.)

UF

60°C

See Article 3.39

Moisture-resistant

75°C

USEe

75°C

Thickness (mm) 0.80 1.20 1.60 2.00 2.40 2.80 3.20 1.60g 2.00g 2.40g

2.0 – 5.5 8.0 – 30 38 – 100 101 – 250 251 – 500 501 – 1 000

1.20 1.60 2.00 2.40 2.80 3.20

Outer Coveringa None

Integral with insulation

Moisture- and heat- resistant

See Article 3.38.

Heat- and moistureresistant

Moistureresistant nonmetallic covering [(See 3.38.1.1(b)]


TW

163

Moistureresistant thermoplastic

Conductor Area (mm2) 2.0 – 5.5 8.0 14 – 30 38 – 100 101 – 250 251 – 500 501 – 1 000 2.0 – 5.5 8.0 – 30 38 – 100

XHH

90°C




XHHWe

90°C


Flame-retardant moisture-resistant thermoset


XHHW-2

90°C


Flame-retardant moisture-resistant thermoset

Modified ethylene tetrafluoroethylene

Z

90°C


150°C




ZWe

75°C

Wet locations

90°C


150°C


Wet locations

Modified ethylene tetrafluoro-ethylene

2.0 – 5.5 8.0 – 30 38 – 100 101 – 250 251 – 500 501 – 1 000 2.0 – 5.5 8.0 – 30 38 – 100 101 – 250 251 – 500 501 – 1 000 2.0 – 5.5 8.0 – 30 38 – 100 101 – 250 251 – 500 501 – 1 000 2.0 – 3.5 5.5 8.0 – 22 30 –38 50 – 100 2.0 – 5.5

0.80 1.20 1.40 1.70 2.00 2.40 0.80 1.20 1.40 1.70 2.00 2.40 0.80 1.20 1.40 1.70 2.00 2.40 0.40 0.50 0.64 0.89 1.20 8.0 – 30

None

None

None

None

None

Some insulations do not require an outer covering. Where design conditions require maximum conductor operating temperatures above 90°C. Listed wire types designated with the suffix “2,” such as RHW-2, shall be permitted to be used at a continuous 90°C operating temperature, wet or dry. g Includes integral jacket. i Insulation thickness shall be permitted to be 2.80 mm for listed Type USE conductors that have been subjected to special investigations. The nonmetallic covering over individual rubber-covered conductors of aluminum-sheathed cable and of lead-sheathed or multiconductor cable shall not be required to be flame retardant. For Type MC cable, see 3.30.3.1. For nonmetallic-sheathed cable, see Part 3.34.3. For Type UF cable, see Part 3.40.3. b e


164 a

Thermoset


ANNEX C Philippine National Standard for Electrical Products 1.

PNS 35-1:2004

-

2.

PNS 35-2:2006

-

3.

PNS 40:1984

-

4.

-

5. 6.

PNS 43:1984 Amendments 01: 1985 PNS 106:1987 PNS 107:1987

7.

PNS 108:1987

-

8.

PNS 109:1987

-

9.

PNS 110:1987

-

10. PNS 111:1987

-

-

11. CDPNS 163:XXXX -

12. PNS 260:2004

-

13. CDPNS 261:XXXX -

Electric wires and cables – Thermoplastic insulated electric copper wires and cables rated 600 volts – Part 1: General specifications Electric wires and cables – Thermoplastic insulated electric copper wires and cables rated 600 volts – Part 1: Non-metallic flat jacketed electric wires – Specifications Electric wires and cables – Copper redraw rod for electrical purposes – Specification Electric wires and cables – EC aluminum redraw rod for electrical purposes – Specification Enameled copper wires – Test method Polyurethane enameled copper wires, class 105 – Specifications Polyester enameled copper wires, class 105 – Specification Polyvinyl formal enameled copper wires, class 105 – Specification Polyester amide-imide enameled copper wires, class 180 - Specification Oleo-resinous enameled copper wires – Specification Electrical products – Polyvinyl chloride insulated flexible cords and fixture wires – Specification Electric wires and cables – Annealed copper wires – Specification Electric wires and cables – PVC insulated low voltages cable for road vehicles – Specification 165

Power Cables & Wires Technical Manual 14. CDPNS 661:XXXX -

15. PNS 662:1992

-

16. PNS 1086:1992

-

17. PNS 1087:1992

-

18. PNS 1088:2006

-

19. PNS 1129:1993

-

20. PNS 1130:1993

-

21. PNS 1207:2006

-

22. PNS 1289:1995

-

23. PNS 1487-1-1:1997 -

24. PNS 1487-1-2:1997 -

25. PNS 1487-1-3:1997 -

Organic chemicals – Plasticized Polyvinyl chloride compounds for electrical insulation – Specification Electrical wires and cables – Ampacities of insulated electric 8u77 conductors, 0-35,000 volts Electrical wires and cables – Harddrawn solid copper wires for electrical purposes – Specification Electrical wires and cables – Hard-drawn copper stranded – Specification Electric wires and cables Copper and aluminum conductors for electrical purposes – Test methods Hard-drawn aluminum wires for electric purposes – Specifications Hard-drawn aluminum stranded conductors – Specification Electric wires and cables – Soft-drawn (annealed) copper stranded conductors for electrical purposes – Specification Electric wires and cables – PVC insulated battery cables – Specification Common test methods for insulating and sheathing materials of electric cables – Part 1: Methods for general application – Section 1: Measurement of thickness and overall dimensions – Test for determining mechanical properties Common test methods for insulating and sheathing materials of electric cables – Part 1: Methods for general application – Section 2: Thermal ageing methods Common test methods for insulating and sheathing materials of electric cables – Part 1: Methods for general application – Section 3: Methods of determining the density – Water absorption tests – Shrinkage 166

Power Cables & Wires Technical Manual 26. PNS 1487-1-4:1997 -

27. PNS 1487-2-1:1997 Amendments 01 & 02:1997

28. PNS 1487-3-1:1997 -

29. PNS 1487-3-2:1997 -

30. PNS 1487-4-1:1997 -

31. PNS 1487-4-2:1997 -

Common test methods for insulating and sheathing materials of electric cables – Part 1: Methods for general application – Section 4: Test at low temperature Common test methods for insulating and sheathing materials of electric cables – Part 2: Methods specific to elastomeric compounds – Section 1: Ozone resistance test–hot set test–Mineral oil immersion test Common test methods for insulating and sheathing materials of electric cables – Part 3: Methods specific to PVC compounds – Section 1: Pressure test at high temperature – Test for resistance to cracking Common test methods for insulating and sheathing materials of electric cables – Part 3: Methods specific to PVC compounds – Section 2: loss of mass test – Thermal stability test Common test methods for insulating and sheathing materials of electric cables – Part 4: Methods specific to polyethylene and polypropelene compounds – Section 1: Resistance to environmental stress cracking – Wrapping test after thermal ageing in air – Measurement of the melt flow index – carbon black and/or mineral content measurement in PE Common test methods for insulating and sheathing materials of electric cables – Part 4: Methods specific to polyethylene and polypropelene compounds – Section 2: Elongation at break after preconditioning – Wrapping test after thermal ageing in air – Measurement of mass increase – Long term stability test – (Appendix A) – Test method for copper167


32. PNS 2048:2006

-

33. PNS ASTM B230: 2005 34. PNS ASTM B231: 2005 35. PNS ASTM B233: 2005 36. PNS ASTM B400: 2005

37. PNS ASTM B609: 2005

38. PNS ASTM B786: 2005

39. PNS ASTM B800: 2005

40. PNS ASTM B801: 2005

41. PNS ASTM B172: 2005

catalysed oxidative degradation (Appendix B) Electric wires and cables – Thermoplastic-insulated underground feeder - Specification Standard Specification for Aluminum 1350-H19 Wire for Electrical Purposes (ASTM published 2004) Standard Specification Concentric-LayStranded Aluminum 1350 Conductors (ASTM published 2004) Standard Specification for Aluminum 1350 Drawing Stock for Electrical Purposes (ASTM published 2003) Standard Specification for Compact Round Concentric-Lay-Stranded Aluminum 1350 Conductors (ASTM published 2004) Standard Specification for Aluminum 1350 Round Wire, Annealed and Intermediate Tempers, for Electrical Purposes (ASTM published 2004) Standard Specification for 19 Wire Combination Unilay-Stranded Aluminum Conductors for Subsequent Insulation (ASTM published 2004) Standard Specification for 8000 Series Aluminum Alloy Wire for Electrical Purposes-Annealed and Intermediate Tempers (ASTM published 2000) Standard Specification Concentric-LayStranded Conductors of 8000 Series Aluminum Alloy for Subsequent Covering or Insulation (ASTM published 1999) Standard Specification for Rope-LayStranded Copper Conductors Having Bunch-Stranded Members, for Electrical Conductors (ASTM published 2001) 168

Power Cables & Wires Technical Manual 42. PNS ASTM B173: 2005

43. PNS ASTM B174: 2005

44. PNS ASTM D1047:2005 45. PNS ASTM D1351:2005

46. PNS ASTM D2219:2005

47. PNS ASTM D2220:2005

48. PNS ASTM D2308:2005

49. PNS ASTM D3554:2005

Standard Specification for Rope-LayStranded Copper Conductors Having Concentric-Stranded members, for Electrical Conductors (ASTM published 2001) Standard Specification for BunchStranded Copper Conductors for Electrical Conductors (ASTM published 2002) Standard Specification for Poly(Vinyl Chloride Jacket for Wire and Cable (ASTM published 2001) Standard Specification for Thermoplastic Polyethylene Insulation for Electrical Wire and Cable (ASTM published 2002) Standard Specification for Poly(Vinyl Chloride) Insulation for Wire and Cable, 60OC Operation (ASTM published 2002) Standard Specification for Poly(Vinyl Chloride Insulation for Wire and Cable, 75OC Operation (ASTM published 2002) Standard Specification for Thermoplastic Polyethylene Jacket for Electrical Wire and Cable (ASTM published 2002) Standard Specification for TrackResistant Black Thermoplastic HighDensity Polyethylene Insulation for Wire and Cable, 75OC Operation (ASTM published 2001)

169


170


Annex D

171


Bibliography 1) Electric Cables Handbook 3rd Edition by Moore (Blackwell, 1997) 2) Cable handbook by Phelps Dodge Philippines 3) National Electrical Code 4) Philippine Electrical Code 5) Wikipedia

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174

2010 Edition Power Cables and Wires Technical Manual

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