GE L30 User Manual

10-4 L30 Line Current Differential System GE Multilin
10.1 TESTING 10 COMMISSIONING
10
10.1.4 LOCAL-REMOTE RELAY TESTS
a) DIRECT TRANSFER TRIP (DTT) TESTS
The direct transfer trip is a function by which one relay sends a signal to a remote relay to cause a trip of remote equipment.
The local relay trip outputs will close upon receiving a direct transfer trip from the remote relay. The test procedure is as fol-
lows:
1. Ensure that relay will not issue any undesired signals to other equipment and all previous tests have been completed
successfully.
2. Cycle power off/on in both relays.
3. Verify and record that both relays indicate In Service on the faceplate display.
4. Make the following setting change in the
SETTINGS  GROUPED ELEMENTS  LINE DIFFERENTIAL ELEMENT  CUR-
RENT DIFFERENTIAL menu of both relays:
CURRENT DIFF FUNCTION: “Enabled”
5. Verify and record that both relays have established communications by performing the following status check thorough
the ACTUAL VALUES  STATUS  CHANNEL TESTS menu:
CHANNEL 1(2) STATUS: “OK”
6. At the remote relay, make the following changes in the SETTINGS  GROUPED ELEMENTS  LINE DIFFERENTIAL ELE-
MENT  CURRENT DIFFERENTIAL menu:
CURRENT DIFF DTT: “Enabled”
7. At the Local relay, make the following changes in the
SETTINGS  INPUTS/OUTPUTS  CONTACT OUTPUT N1 menu:
CONTACT OUTPUT N1 OPERATE: “87L DIFF RECVD DTT”
8. At the Local relay, verify that ACTUAL VALUES  STATUS  CONTACT OUTPUTS  Cont Op N1 is in the “Off” state.
9. Apply current to phase A of the remote relay and increase until 87L operates.
10. At the Local relay, observe
ACTUAL VALUES  STATUS  CONTACT OUTPUTS  Cont Op N1 is now in the “On” state.
11. Repeat steps 8 through 10 for phases A and B and observe Contact Outputs N2 and N3, respectively.
12. Repeat steps 8 through 11 with the Remote and Local relays inter-changed.
13. Make the following setting change in the
SETTINGS  GROUPED ELEMENTS  LINE DIFFERENTIAL ELEMENT  CUR-
RENT DIFFERENTIAL menu of both relays:
CURRENT DIFF FUNCTION: “Disabled”
14. At the Remote relay, set SETTINGS  INPUTS/OUTPUTS  CONTACT OUTPUT N1  CONTACT OUTPUT N1 OPERATE to
the
CURRENT DIFF KEY DTT operand.
15. At the Local relay, observe under the
ACTUAL VALUES  STATUS  CONTACT OUTPUTS menu that CONTACT OUTPUT
N1
, N2 and N3 are “Off”.
16. At the Remote relay, set SETTINGS  TESTING  FORCE CONTACT INPUTS  FORCE Cont Ip N1 to “Closed”.
17. At the Local relay, observe under
ACTUAL VALUES  STATUS  CONTACT OUTPUTS that CONTACT OUTPUT N1, N2 and
N3 are now “On”.
18. At both the Local and Remote relays, return all settings to normal.
b) FINAL TESTS
As proper operation of the relay is fundamentally dependent on the correct installation and wiring of the CTs, it must be con-
firmed that correct data is brought into the relays by an on-load test in which simultaneous measurements of current and
voltage phasors are made at all line terminals. These phasors and differential currents can be monitored at the
ACTUAL VAL-
UES
 METERING  87L DIFFERENTIAL CURRENT menu where all current magnitudes and angles can be observed and con-
clusions of proper relay interconnections can be made.

GE L30 Specifications

General

Brand	GE
Model	L30
Category	Relays
Language	English