3.78
SEL-400 Series Relays Instruction Manual Date Code 20171006
Basic Relay Operations
Readying the Relay for Field Application
This procedure is a guide to help you ready the relay for field application. If you
are unfamiliar with the steps in this procedure, see the many relay usage exam-
ples presented in this section. This is a suggested procedure; modify the proce-
dure as necessary to conform to your standard company practices.
Step 1. Open the appropriate low-voltage breaker(s) and remove fuses to ver-
ify removal of control power and ac signals from the relay.
Step 2. Isolate the relay TRIP control output.
Step 3. Perform point-to-point continuity checks on the circuits associated
with the relay to verify the accuracy and correctness of the ac and dc
connections.
Step 4. Apply power to the relay.
The green ENABLED LED on the front panel will illuminate.
Step 5. Use an SEL-C234A cable to connect a serial terminal to the relay.
Step 6. Start the terminal (usually a PC with terminal emulation software).
Step 7. Establish communication with the relay at Access Level 0.
Step 8. Proceed to Access Level 2 (see Changing the Default Passwords in
the Terminal on page 3.10).
Step 9. Change the default passwords (see Changing the Default Passwords
in the Terminal on page 3.10).
Step 10. Set the DATE and TIME (see Making Simple Settings Changes on
page 3.15).
Step 11. Use test sources to verify relay ac connections (see Examining
Metering Quantities on page 3.35).
Step 12. Verify control input connections.
Step 13. Verify control output connections.
Step 14. Perform protection element tests.
Step 15. Set the relay (see Making Simple Settings Changes on page 3.15,
Section 12: Settings, and Section 6: Protection and Protection Appli-
cation Examples in the product-specific instruction manual.
Step 16. Connect the relay for tripping/closing duty.
Step 17. From Access Level 2, use a communications terminal to issue appli-
cable commands (listed in Ta ble 3.9) to clear the relay data buffers.
Step 18. Connect the secondary voltage and current inputs.
Step 19. Use the MET command or the QuickSet HMI to view relay metering
to confirm secondary connections (see Examining Metering
Quantities on page 3.35).
Table 3.9 Communications Port Commands That Clear Relay Buffers
Communications Port Command Task P e rf ormed
MET RD Reset demand meter data
MET RP Reset peak demand meter data
MET RE Reset energy meter data
MET RM Reset maximum/minimum meter data
HIS CA Reset event report and history buffers
SER CA Reset Sequential Events Recorder data
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