10.6
Testing and Troubleshooting
Commissioning Tests
SEL-787 Relay
correctly, taking into account the relay PTR, CTR1, and CTR2
settings and the fact that the quantities are displayed in primary
units.
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
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
your application.
Step 22. Use the serial port commands in
data buffers and prepare the relay for operation.
This prevents data generated during commissioning testing
from being confused with operational data collected later.
Table 10.2 Serial Port Commands That Clear Relay Data Buffers
Serial Port Command
Task Performed
LDP C
Clears Load Profile Data
SER R
Resets Sequential Events Record buffer
SUM R
Resets Event Report and Summary Command buffers
Instruction Manual
function, check the control input
are changed back to the correct values for
Table 10.2
to clear the relay
Date Code 20081022
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