CONTENTS
1
Description of Operation
2
Performance Specification / Technical Data
3
Applications Guide
4
Installation
5
Commissioning
6
Maintenance
7
Diagrams
This manual covers all 2TJM relays manufactured from September 1997. Earlier relays do not necessarily incorporate all the features described. Our policy of continuous improvement may mean that extra features and functionality have been added. The Copyright and other intellectual property rights in this document, and in any model or article produced from it (and including any Registered or unregistered design rights) are the property of Reyrolle Limited. No part of this document shall be reproduced or modified or stored in another form, in any data retrieval system, without the permission of Reyrolle Limited, nor shall any model or article be reproduced from this document unless Reyrolle Limited consent. While the information and guidance given in this document is believed to be correct, no liability shall be accepted for any loss or damage caused by any error or omission , whether such error or omission is the result of negligence or any other cause. Any and all such liability is disclaimed. ©1997
Reyrolle Limited.
DESCRIPTION OF OPERATION
1
1
DESCRIPTION OF OPERATION Contents 1.
INTRODUCTION
1
2. 2.1. 2.2. 2.3. 2.4.
RELAY DESIGN Basic 2TJM IDMT Relay Basic 2TJM IDMT + Highset Relay Basic 2TJM IDMT Directional Relay Basic 2TJM IDMT with A.C. Series Tripping Relay
1 1 1 1 1
3. 3.1. 3.2. 3.3. 3.4. 3.5.
DESCRIPTION OF FEATURES 2TJM10 Range 2TJM20 Range 2TJM30 Range 2TJM60 2TJM70 Range
1 1 2 2 2 2
FIGURE 1 FIGURE 2 FIGURE 3
IDMTL ELEMENT: ELECTRO-MAGNETIC SYSTEM DIRECTIONAL ELEMENT: ELECTRO-MAGNETIC SYSTEM IDMTL AND HIGHSET WITH A.C. SERIES TRIPPING
3 3 4
DESCRIPTION OF OPERATION where, Is In Ml M2
1. INTRODUCTION Electromechanical Inverse Definite Minimum Time relays operating on the induction disc principle offer a reliable, long term protection, that imposes no standing drain on substation battery supplies. Their operation is easy to understand, they are easy to test and maintain and have an extremely long service life. Experience gained in the manufacture and application of induction disc relays has resulted in the development of the 2TJM series. The new series incorporates a number of assembly improvements, introduces better moulding materials while retaining, unchanged, the TJM magnetic circuit. In particular 2TJM relays are designed to comply with IEC 255 series specifications where applicable.
= = = =
Set Current Relay nominal current rating Plug setting A marked multiplying factor
2.2. Basic 2TJM IDMT + Highset Relay An instantaneous high-set element type MCAA is included with its operating coil connected in series with the IDMT operating coil. Current setting is by a calibrated continuously variable cam and a plug bridge with x I and x2 positions providing an overall 4: I setting ratio. A protection lockout setting, "L", where the contacts are held open is also provided. 2.3. Basic 2TJM IDMT Directional Relay
The full 2TJM range has the following IDMT characteristics, based on IEC 255-4 characteristics: 2TJM10 series 2TJM20 series 2TJM30 series 2TJM60 2TJM70 series
A directional element (Fig.2.), type ES, operating on the induction wattmeter principle drives a contact which when closed completes the IDMT secondary magnet circuit. With an applied current, in the reverse direction, above the IDMT setting the induction disc will not move while the secondary magnet remains de-energised, or if the disc has moved from its starting point it will reset when the secondary magnet is deenergised; reset time depending upon the distance travelled by the disc.
- Normal inverse, form 3/10 - Very inverse - Extremely inverse - Long time inverse, form 5/30 - Normal inverse, form 1.3/10
2. RELAY DESIGN 2.1. Basic 2TJM IDMT Relay
Torque to operate the directional element is derived from the magnetic field developed from it's current and voltage coils, maximum torque occurs in the operate direction when the current and voltage are in phase. However under the various system fault conditions the system voltage and system power factor may be considerably reduced. To meet these requirements the electromagnetic circuit has three coils to provide loss of voltage compensation and is able to provide reliable operation to voltages as low as 2% of nominal rating and is arranged to develop maximum torque at the probable phase angle introduced by fault conditions. Directional overcurrent relays have the 45° lead power factor characteristic using the 90° connection, i.e. A- Phase current is polarised by B-C voltage. Directional earth fault relays are supplied with a 12.5° lagging power factor characteristic, the voltage coil being connected to an open delta tertiary winding of the line voltage transformer, the relay voltage coil is therefore suitable for 190V and 63.5V for resistance and solidly earthed systems respectively.
The relay comprises a die-cast frame which carries all the subassemblies of induction disc, electro-magnetic system, operating coil, plug bridge and the contact assembly. The electro-magnetic system (Fig. l.) comprises primary and secondary magnets arranged with four air gaps each contributing to the driving torque. The primary magnet is energised by the primary coil which is tapped so that the required fault setting can be made. Tappings are selected from the plug bridge which automatically selects the highest tap setting as the setting plug is withdrawn. A second winding is energised by the primary coil and serves to energise the secondary magnet. The contact operating arm and the flag indicator are carried on a single moulding and form a complete sub-assembly. Two normally open contacts are provided of the bridging type, the operating arm being driven from a cam track at the hub of the induction disc. This gives considerable mechanical advantage at the instant of contact touch and ensures high contact pressures even at low operating current levels making the contacts suitable for direct tripping without series or shunt relays. A hand reset flag indicator is released which shows a high luminance red indicator.
2.4. Basic 2TJM IDMT with A.C. Series Tripping Relay The standard 2TJM construction has a rectifier operated B33 element with hand reset contacts included (fig. 3). This provides the heavy duty break contact required to switch the secondary C.T. secondary current to the circuit breaker trip coil when the relay completes it's operation.
Relay operating time is determined by the starting position of the induction disc, this is set by the time multiplier dial calibrated from 0.1 to 1.0, there is also a "T" mark, before the 0.1 setting, in this position the contacts are held closed, locked out. Settings are applied in amps following the instructions printed on the relay label which are in the form:
3. DESCRIPTION OF FEATURES 3.1. 2TJM10 Range The operating time characteristic is generally applied in time/current graded schemes for overcurrent, earth fault protection and stand-by earth fault protection on solidly
Is =InxMI xM2 1
1
1
DESCRIPTION OF OPERATION earthed systems.
3.5. 2TJM70 Range
The 2TJM10 range is as follows:
The operating time form 1.3/10 characteristic is generally applied in time/current graded schemes for overcurrent and earth fault protection.
2TJM10 2TJM 11 2TJM12 2TJM13 2TJM14 2TJM16
- Normal inverse IDMT form 3/10 relay - IDMT + highset element relay - Directional IDMT relay - IDMT with A.C. series tripping relay - IDMT and highset with A.C. series tripping relay - Directional IDMT + highset element relay
The 2TJM70 range is as follows: 2TJM70 2TJM71 2TJM72 2TJM73 2TJM74
3.2. 2TJM20 Range The operating time characteristic is generally applied in time/current graded schemes for overcurrent, earth fault protection and stand-by earth fault protection on solidly earthed systems. The 2TJM20 range is as follows: 2TJM20 2TJM21 2TJM22
- Very inverse IDMT relay - IDMT + highset element relay - Directional IDMT relay
3.3. 2TJM30 Range The operating time characteristic is generally applied in time/current graded schemes for overcurrent earth fault protection or where co- ordination with fuses is required. The relay design differs from the basic 2TJM type by providing two normally open contacts where one for trip duty is of the bridging type and the other is a series operated reed relay energised by the circuit breaker trip coil current. If the trip coil takes less than 0.8 amp a voltage operated repeat can be fitted. The trip duty moving and fixed contacts, the contact operating arm and the flag indicator are carried on a single moulding and form a complete sub-assembly. The 2TJM30 range is as follows: 2TJM30 2TJM31 2TJM32
- Extremely IDMT relay - IDMT + highset element relay - Directional IDMT relay
3.4. 2TJM60 The operating time characteristic is generally applied in time/current graded schemes for stand-by earth fault protection on resistance or impedance earthed schemes. The relay design differs from the basic 2TJM type by providing two normally open contacts where one for trip duty is of the bridging type and the other is a series operated reed relay energised by the circuit breaker trip coil current. If the trip coil takes less than 0.8 amp a voltage operated repeat can be fitted. The trip duty moving and fixed contacts, the contact operating arm and the flag indicator are carried on a single moulding, and form a complete sub-assembly. The 2TJM60 is a long time inverse form 5/30 relay.
2
- Fast normal inverse IDMT form 1.3/10 relay - IDMT + highset element relay - Directional IDMT relay - IDMT with A.C. series tripping relay - IDMT and highset with A.C. series tripping relay
DESCRIPTION OF OPERATION
Primary Magnet To Line C.T.
Induction Disc Secondary Magnet
To Directional Element Contact (When used)
Figure 1 IDMTL Element: Electro-magnetic System
To Line C.T.
To Secondary Coil (See Figure 1)
* Aluminium Sector
Shading Ring
Resistance
To Line V.T.
closed when * Contact current flow is in direction of operation
Figure 2 Directional Element: Electro-magnetic System
3
1
1
DESCRIPTION OF OPERATION
C.T.
C.B.
X
Trip Coil
2TJM14 2TJM
2TJM
9
MCAA 10
B33
MCAA
1
2
11
12
4
Figure 3 IDMTL and Highset with A.C. Series Tripping
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