GE UR Series Instruction Manual

Also see for L90: Communications manual Communications guide Instruction manual Instruction manual Instruction manual

Contents

10-46L90 Line Differential RelayGE Power Management10.9 L90 COMMISSIONING TESTS 10 COMMISSIONING10Download the L90 Test software from the GE Power Management website (www.GEindustrial.com/pm) or con-tact GE Power Management for information about the L90 current differential test program which allows the user tosimulate different operating conditions for verifying correct responses of the relays during commissioning activities.10.9.4 LOCAL-REMOTE RELAY TESTSa) DIRECT TRANSFER TRIP (DTT) TESTSThe 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.TEST PROCEDURE:1. Ensure that relay will not issue any undesired signals to other equipment and all previous tests have been completedsuccessfully.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 both relays:SETTINGS / GROUPED ELEMENTS / LINE DIFFERENTIAL ELEMENTS / CURRENT DIFFERENTIAL / FUNCTION: Enabled5. Verify and record that both relays have established communications by performing the following status check:ACTUAL VALUES / STATUS / CHANNEL TESTS / CHANNEL 1(2) STATUS: OK6. At the remote relay, make the following setting change:SETTINGS / GROUPED ELEMENTS / LINE DIFFERENTIAL ELEMENTS / CURRENT DIFFERENTIAL DTT: Enabled7. At the Local relay set"SETTINGS / INPUTS/OUTPUTS / CONTACT OUTPUT N1 to operand 87L DIFF RECVD DTT A.SETTINGS / INPUTS/OUTPUTS / CONTACT OUTPUT N2 to operand 87L DIFF RECVD DTT B.SETTINGS / INPUTS/OUTPUTS / CONTACT OUTPUT N3 to operand 87L DIFF RECVD DTT C.8. At the Local relay, observe 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 both relays:SETTINGS / GROUPED ELEMENTS / CURRENT DIFFERENTIAL / FUNCTION: "Disabled"14. At the Remote relay, set SETTINGS / INPUTS/OUTPUTS / CONTACT INPUT N1 to operand CURRENT DIFF KEY DTT.15. At the Local relay, observe under ACTUAL VALUES / STATUS / CONTACT OUTPUTS that CONTACT OUTPUT N1, N2 and N3 are“Off”.16. At the Remote relay, set SETTINGS / TESTING / FORCE CONTACT INPUTS / FORCE CONTACT INPUT N1 to “Closed”.17. At the Local relay, observe under ACTUAL VALUES / STATUS / CONTACT OUTPUTS that CONTACT OUTPUT N1, N2 and N3 arenow “On”.18. At both the Local and Remote relays, return all settings to normal.b) FINAL TESTSAs 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 andvoltage phasors are made at all line terminals. These phasors and differential currents can be monitored at the ACTUALVALUES / METERING / 87L DIFFERENTIAL CURRENT menu where all current magnitudes and angles can be observed and con-clusions of proper relay interconnections can be made.NOTE