Sel SEL-787 - Table 10.2 Serial Port Commands that Clear Relay Data Buffers

10.6
SEL-787 Relay Instruction Manual Date Code 20150130
Testing and Troubleshooting
Commissioning Tests
Step 15. If you are using a current transformer for the neutral, apply a
single-phase current to the IN1 terminal. Do not apply voltage.
Step 16. Verify that the relay is measuring the magnitude and phase
angle correctly.
The expected magnitude is (applied current) •
(CTRN1). The
expected phase angle is zero (0).
Step 17. Verify control input connections. Using the front-panel
MAIN > Targets > Row 21 function, check the control input
status in the relay (IN101 or IN102).
As you apply rated voltage to each input, the position in
Row 21 corresponding to that input should change from zero
(0) to one (1).
Step 18. Verify output contact operation:
a. For each output contact, set the input to logical 1. This
causes the output contact to close. For example, setting
OUT101 = 1 causes the output OUT101 contact to close.
b. Repeat the process for all contact outputs.
Make sure that each contact closure does what you
want it to do in the annunciation, control, or trip circuit
associated with that contact closure.
Step 19. Perform any desired protection element tests. Perform only
enough tests to prove that the relay operates as intended;
exhaustive element performance testing is not necessary for
commissioning.
Step 20. Connect the relay for tripping duty.
Step 21. Verify that any settings changed during the tests performed in
Step 18 and Step 19 are changed back to the correct values for
your application.
Step 22. Use the serial port commands in Table 10.2 to clear the relay
data buffers and prepare the relay for operation.
This prevents data generated during commissioning testing
from being confused with operational data collected later.
Step 23. When it is safe to do so, energize the transformer.
Step 24. Verify the following ac quantities by using the front-panel
METER > Fundamental or serial port METER command.
➢ Phase current magnitudes should be nearly equal.
➢ Phase current angles should be balanced, have proper
phase rotation, and have the appropriate phase
relationship to the phase voltages.
Table 10.2 Serial Port Commands That Clear Relay Data Buffers
Serial Port Command
Task Per fo r m ed
LDP C
Clears Load Profile Data
SER R
Resets Sequential Events Record buffer
SUM R
Resets Event Report and Summary Command buffers