24-TMSS-01-R0

TRANSMISSION MATERIALS STANDARD SPECIFICATION

24-TMSS-01, Rev. 0

TABLE OF CONTENTS

1.0

SCOPE

2.0

CROSS REFERENCES

3.0

APPLICABLE CODES AND STANDARDS

4.0

DESIGN AND CONSTRUCTION REQUIREMENTS 4.1 4.2 4.3 4.4 4.5

5.0

TESTS 5.1

6.0

24TMSS01R0/YBQ

General Design Criteria Materials Fabrication Drawings

Type (Design) Tests

DATA SCHEDULE

Date of Approval: March 18, 2006

PAGE NO. 2 OF 13


1.0

24-TMSS-01, Rev. 0

SCOPE This SEC Transmission Material Standard Specification (TMSS) specifies the minimum technical requirements for design, engineering, manufacture, inspection, testing and performance of indoor/outdoor Metallic Cable Tray System, intended to be used in the system of the Saudi Electricity Company (SEC), Saudi Arabia.

2.0

CROSS REFERENCES This Material Standard Specification shall always be read in conjunction with SEC General Specification No. 01-TMSS-01, titled "General Requirements for All Equipment/Materials", which shall be considered as an integral part of this TMSS. This TMSS shall also be read in conjunction with SEC Purchase Order or Contract Schedules for project, as applicable.

3.0

APPLICABLE CODES AND STANDARDS The latest revision/amendments of the following Codes and Standards shall be applicable for the equipment/material covered in this TMSS. In case of conflict, the vendor/manufacturer may propose equipment/material conforming to one group of Industry Codes and Standards quoted hereunder without jeopardizing the requirements of this TMSS. 3.1

IEC 61537

Cable Tray Systems and Cable Ladder Systems for Cable Management

3.2

NEMA VE-1

Metal Cable Tray Systems

3.3

NEMA VE-2

Metal Cable Tray Installation Guidelines

3.4

ANSI/NFPA 70

National Electrical Code

3.5

ASTM A90/A90M

Test Method for Weight [Mass] of Coating on Iron and Steel Articles with Zinc or Zinc Alloy Coatings

3.6

ASTM A123/A123M

Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products

3.7

ASTM A153

Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware

3.8

ASTM A780

Standard Practice for Repair of Damaged and Uncoated Areas of Hot Dip Galvanized Coatings

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4.0

24-TMSS-01, Rev. 0

DESIGN AND CONSTRUCTION REQUIREMENTS 4.1

4.2

4.3

General 4.1.1

Metallic cable trays shall meet or exceed the requirements of this specification in all respects.

4.1.2

Metallic cable trays shall be manufactured in accordance with NEMA VE1& VE-2 standards or equivalent IEC standard.

4.1.3

Metallic cable trays shall be designed as a mechanical support for standard approved cables or raceway and not intended to be a walkway for personel.

Design Criteria 4.2.1

Metallic cable trays shall be standard approved type as specified in data schedule.

4.2.2

Metallic cable trays shall have suitable strength and rigidity to provide adequate support without undue sag and shall not have sharp edges, burrs or projections that can damage the cable insulation or jackets.

4.2.3

Allowable load capacity of the metallic cable tray shall be the static weight of cables plus an allowance of 20 % spare. A concentrated static load at midspan shall withstand 890 N static load without collapse.

4.2.4

The metallic cable tray load safety factor shall be at least 1.5. The next nearest higher tray designation per NEMA VE-1 shall be selected when the allowable load capacity falls within NEMA range.

4.2.5

Cable tray shall be designed to provide a minimum of 20 % spare space.

4.2.6

Cable tray deflection shall be restricted to a maximum of 12 mm for all span lengths. Technical details to arrive this term shall also be furnished.

4.2.7

Cable tray shall be supplied with suitable rubber bumpers at locations of safety hazards.

Materials Cable tray shall be fabricated either from corrosion resistant metal such as aluminum alloy or carbon steel with corrosion resistant coating such as zinc coatings as specified in the data schedule.

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4.3.1

24-TMSS-01, Rev. 0

Indoor Installations a.

Aluminum Cable tray straight sections, fitting side rails and rungs made from 6063-T6 aluminium extrusions shall be of heat-treated alloys for further strengthening and shall be copper free suitable for salt laden atmospheres.

b.

Carbon Steel i. Carbon steel used for cable trays shall be protected against corrosion by the following processes: Hot-dip galvanized zinc after fabrication in accordance with ASTM A123/A123M, Coating Grade 65 with an average zinc coating weight of 460 g/m² per side or coating thickness of 0.065 mm (2.55 mils) per side. ii. Carbon steel nuts and bolts shall be hot dip galvanized per 01TMSS-01.

4.3.2

Outdoor Installations Metallic cable tray for outdoor installations shall be hot dip galvanized zinc or anodized aluminum, as applicable.

24TMSS01R0/YBQ

a.

Carbon steel cable trays intended for installation in corrosive or highly corrosive environments with severe alkaline and acidic conditions shall be hot-dip galvanized zinc after fabrication. The minimum thickness of zinc coating shall be as per 01-TMSS-01.

b.

Aluminum cable trays for outdoor application shall be anodized.

c.

PVC coating shall not be used for galvanized steel or aluminum cable trays.

d.

Cuts and damaged areas of hot dip galvanized steel cable tray shall be repaired with compatible material provided by manufacturer to ensure coating integrity.

e.

Approved corrosion inhibiting compound shall be applied at the junction of dissimilar metal such as aluminum alloy and galvanized steel to prevent the galvanic corrosion at a wet atmosphere.

f.

Vetilated flanged covers shall be used for protecting cables against sunlight without accumulation of heat.


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g. 4.4

24-TMSS-01, Rev. 0

Steel nuts and bolts shall be zinc coated per 01-TMSS-01.

Fabrication 4.4.1

Cable Tray Types a.

Ladder Type Ladder tray shall be prefabricated structure of two longitudinal side rails connected by individual transverse members (rungs) with openings in the longitudinal direction. Spacing of rung shall be 150 mm per NEMA VE-1. When the number of cables to be accommodated per tray is less, then spacing of rung can be 225 mm or 300 mm per NEMA VE1 subject to approval by SEC.

b.

Trough Type Trough tray shall be prefabricated structure greater than 102 mm in width consisting of a ventilated/perforated bottom within integral or separate longitudinal side rails.

c.

Solid-Bottom Trays Solid bottom tray shall be prefabricated tray consisting of a bottom with no openings within integral or separate longitudinal side rails.

d.

Channel Type Channel tray shall be prefabricated structure consisting of a one-piece support with either a ventilated or solid bottom channel section not exceeding 150 mm in width.

4.4.2

Cable Tray Dimensions a.

24TMSS01R0/YBQ

Dimensions for various types of cable trays shall be per Table I.


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24-TMSS-01, Rev. 0


Table I

Type Of Tray

Length (mm)

Width (mm)

3660 or 7320

150, 300, 450 600, 750 or 900 150, 300, 450 600, 750 or 900 150, 300, 450 600, 750 or 900 75,100 or 150

Ladder

Trough Solid Bottom Channel b.

4.4.3

Depth (mm)

Radii (mm)

Degree of Arc for Elbows

300 , 600 or 900

30º, 45º, 60º or 90º

75, 100, 125 or 150 75,100, 125 or 150 75, 100, 125 or 150 30 to 45

Thickness of all materials used for cable tray sections, supports etc., shall not be less than 2 mm.

Finish Touch Up Cable trays that have a hot dip galvanized coating applied after fabrication need to be retouched after cutting, drilling or deburring or if the cutting gets damaged. These operations leave bare metal edges that will begin to corrode immediately. Touch up of the galvanized finish must be done per practices given in ASTM A780. Zinc-rich paint that is used for touch up shall meet the requirement of ASTM A780. An area up to 26 mm beyond the bare metal area shall always be painted to prevent corrosion.

4.4.4

Fittings a.

Fitting is a device, which is used to change the direction in either horizontal or vertical planes, or size of cable tray system. Fittings shall be of the same material as the straight section part of the cable tray. The manufacturer shall supply all fittings as required.

b.

Fittings shall have bend or channel radius same as cable trays as indicated in Table I.

c.

Examples of fittings are: i. ii. iii. iv.

24TMSS01R0/YBQ

Horizontal Elbow (Horizontal Bend) Horizontal Tee Vertical Elbow Horizontal Cross


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d.

4.4.5

Approved expansion joint fittings shall be provided where the cable trays cross building expansion joints.

Connectors (Splice Plate) a.

Connectors shall be used to join tray straight sections and/or fittings together. The manufacturer shall supply all connectors as required.

b.

Basic types of connectors are: i. ii. iii. iv.

c.

4.4.6

Accessories a.

Accessories shall cover items that are needed as supplement to straight sections and fittings to complete the cable tray system.

b.

Accessories include dropouts, covers, conduit, adapters, hold down devices (clamps), anchors, bonding jumpers, barriers strips or dividers. They shall be supplied by the manufacturer for a complete cable tray system.

c.

Anchors shall include the following. Expansion anchors in hollow or solid masonry. Machine screws, bolts or welded studs in metal surfaces. Wood screws in wood surfaces. Self drilling anchors or power driven studs in concrete surfaces.

d.

If specified in the Data Schedule, cable barriers shall be used to separet cable rated voltage systems, such as when cables above and below 600/1000 V per Section 392.6 (F) of ANSI/NFPA 70 are installed in the same cable tray. The cable barriers shall be solid, fixed, continuous and constructed of the same material as the cable tray.

e.

Covers shall have self ventilated louvered openings and shall be made of the same material type as the cable tray.

Cable Tray Supports a.

24TMSS01R0/YBQ

Rigid Expansion Adjustable Reducer

The maximum resistance across any fixed splice connections shall be 330 µΩ (micro ohms).

i. ii. iii. iv.

4.4.7

24-TMSS-01, Rev. 0

Cable tray supports shall provide adequate supporting means for cable tray straight sections and/or fittings as specified in clause no. 4.2.5. They shall include, but not limited to, cantilever bracket, trapeze and Date of Approval: March 18, 2006

PAGE NO. 8 OF 13


24-TMSS-01, Rev. 0

individual rod suspension. Supporting steelworks shall be hot-dip galvanized in accordance with 01-TMSS-01. b.

4.4.8

All supports shall be supplied by the manufacturer. Cable supports shall have a maximum of 6 m spacing on horizontal run and 2.4 m spacing on the vertical runs. However when the tray system is supported from building structure with rods, brackets etc., the maximum span shall be 1.5 mm.

Thermal Contraction and Expansion Accurate gap setting at the time of installation is necessary for the proper operation of the expansion splice plates. Procedures as outlined in NEMA VE-1and NEMA VE-2 shall be followed to determine the required expansion joint gap setting. Further spacing between expansion joints shall be per NEMA VE-1 &VE-2 standards.

4.4.9

4.5

Grounding and Electrical Continuity a.

Metallic cable trays shall be grounded to the grounding network to limit voltages during fault condition and electrically continuous per Section 392 of ANSI/NFPA 70.

b.

Cable tray sections, fittings and connected raceways shall be bonded properly using bonding jumper at both ends. The bonding jumper shall be bare copper conductor of 50 mm2 size and 400 mm long.

c.

Metallic cable tray shall not be used as equipment grounding conductors.

Drawings Metallic cable tray manufacturer shall provide drawing showing the following as minimum requirements. The drawing shall be drawn to scale . 4.5.1

Type (Ladder, trough, etc.)

4.5.2

Dimensions per Table I

4.5.3

Straight section and/or fittings

4.5.4

Radii

4.5.5

Vertical and horizontal changes in direction

4.5.6

Layout and details of thermal contraction and expansion joint

4.5.7

Connectors

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5.0

4.5.8

Reducers

4.5.9

Accessories (Tray cover, divider, etc.)

4.5.10

Number of Trays

4.5.11

Support layout and details

4.5.12

Grounding and electrical continuity

24-TMSS-01, Rev. 0

TESTS All test results shall be provided for review and acceptance by SEC. 5.1

Type (Design) Tests Metallic cable tray shall meet the following Type (Design) Tests in accordance with the test requirements of NEMA VE-1. 5.1.1

Destruction Load Test Test shall be conducted per NEMA VE-1. The destruction load shall be at least 1.5 times the working load capacity as requested in Data Schedule with support spacing per clause 4.4.7. A graph indicating destructive load (kg/m) versus support spacing (m) for the tray offered shall be furnished.

5.1.2

Deflection Test Test shall be conducted per NEMA VE-1. Maximum deflection shall be restricted to 12 mm.

5.1.3

Electrical Continuity of Connections Test shall be per NEMA VE-1. Two 600 mm lengths of side rail shall be joined together using the mechanical connecter. A current of 30 A dc shall be passed through the specimen. The net resistance of the splice connections shall not exceed 330 µ Ω (micro ohms).

5.1.4

Galvanizing Test Test shall be in accordance with ASTM A90/90M. Minimum weight of coating shall be per ASTM standards indicated above.

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24-TMSS-01, Rev. 0


6.0

DATA SCHEDULE

METALLIC CABLE TRAY SYSTEMS SEC Enquiry No.

Date:

SEC Purchase Order No. or Contract No.

Date:

SEC PTS No./Project Title with J.O. No. REFERENCE SECTION NO.

3.0

DESCRIPTION

'A'

'C'

APPLICABLE CODES AND STANDARDS Applicable industry standard

*

4.0

DESIGN AND CONSTRUCTION REQUIREMENTS

4.2

Design Criteria

4.2

'B'

Tray designation

*

Working load capacity (kg/m)

*

Safety factor

1.5

Maximum deflection (mm)

12

Materials Type of material (Al / Steel) Type of protection a) If aluminum alloy, b) If carbon steel,

'A''B''C'(*)-

SEC SPECIFIED DATA/PARAMETER. BIDDER/SUPPLIER/VENDOR/CONTRACTOR PROPOSED DATA/PARAMETERS. REMARKS SUPPORTING THE PROPOSED DEVIATION IN COLUMN 'B'. DATA/PARAMETER TO BE PROVIDED/PROPOSED BY THE BIDDER/SUPPLIER/ VENDOR/CONTRACTOR IN COLUMN 'B'.

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24-TMSS-01, Rev. 0


6.0

DATA SCHEDULE

METALLIC CABLE TRAY SYSTEMS

REFERENCE SECTION NO. 4.4

DESCRIPTION

'A'

'B'

'C'

Fabrication Type of Cable Tray (Ladder, Trough, Solid Bottom, Channel) Rung spacing for ladder type tray (mm)

*

Minimum thickness of material (mm)

2

Span length (mm)

*

Moment of Ineria (mm4)

*

Section modulus for two side rails (mm 3)

*

Are Cable Barriers Required? Finish touch up

24TMSS01R0/YBQ

Yeas / No *


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24-TMSS-01, Rev. 0


7.0

DATA SCHEDULE

METALLIC CABLE TRAY SYSTEMS A.

ADDITIONAL TECHNICAL INFORMATION OR FEATURES TO BE FURNISHED BY SEC:

B.

ADDITIONAL SUPPLEMENTARY DATA OR BIDDER/VENDOR/SUPPLIER/CONTRACTOR:

B.

OTHER PARTICULARS TO BE FILLED UP BY BIDDER/VENDOR/SUPPLIER/ CONTRACTOR:

FEATURES

Actual Manufacturer of Equipment/Material

PROPOSED

BY

Vendor/Supplier/ Contractor

Name of the Company Location and address

Name and Signature of authorized epresentative and date

Official Seal/Stamp of the Company & Date

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24-TMSS-01-R0

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