10.3
Date Code 20150130 Instruction Manual SEL-787 Relay
Testing and Troubleshooting
Commissioning Tests
Step 6. Remove the 1 ACI/3 AVI board or 1 ACI board from Slot E.
Step 7. Locate jumper JMP1 and change it from Pin 1-2 (normal
position) to Pin 2-3 (low-level test position)
Step 8. Locate connector J3 and connect low-level signal connector
(e.g., ribbon cable connector of SEL-RTS Test System).
Step 9. Insert the board back into Slot E.
Refer to the SEL-RTS Instruction Manual for additional detail.
When simulating a delta PT connection, DELTA_Y := DELTA, with the low-
level test interface referenced in Figure 10.1, apply the following signals:
➤ Apply low-level test signal VAB to Pin VA.
➤ Apply low-level test signal –VBC (equivalent to VCB) to
Pin VC.
➤ Do not apply any signal to pin VB.
Commissioning Tests
SEL performs a complete functional check and calibration of each SEL-787
before it is shipped. This helps to ensure that you receive a relay that operates
correctly and accurately. Commissioning tests confirm that the relay is
properly connected including the control signal inputs and outputs.
The following connection tests help you enter settings into the SEL-787 and
verify that the relay is properly connected. Brief functional tests ensure that
the relay settings are correct. It is unnecessary to test every element, timer, and
function in these tests. Modify the procedure as necessary to conform to your
standard practices. Use the procedure at initial relay installation; you should not need
to repeat it unless major changes are made to the relay electrical connections.
Required Equipment
➤ The SEL-787, installed and connected according to your
protection design
➤ A PC with serial port, terminal emulation software, and serial
communications cable
➤ SEL-787 Settings Sheets with settings appropriate to your
application and protection design
➤ The ac and dc elementary schematics and wiring diagrams for
this relay installation
➤ A continuity tester
➤ A protective relay ac test source
➢ Minimum: single-phase voltage and current with phase
angle control
➢ Preferred: three-phase voltage and current with phase
angle control
Connection Tests
Step 1. Remove control voltage and ac signals from the SEL-787 by
opening the appropriate breaker(s) or removing fuses.
Step 2. Isolate the relay contact assigned to be the TRIP output.
NOTE: The 14-pin connectors of the
SEL-RTS ribbon cable C750A can be
used. The connectors are not keyed;
make sure Pin 1 is connected to the
IAW1/VA channel on the 6 ACI and
1 ACI/3 AVI boards, respectively.
To Next Page
Loading...
