Sel 751A, Instruction Manual

Page: 396 / 640

10.4
SEL-751A Relay Instruction Manual Date Code 20100129
Testing and Troubleshooting
Commissioning Tests
Figure 10.2 Three-Phase Open-Delta AC Connections
Step 12. Apply rated current (1 A or 5 A).
Step 13. If the relay is equipped with voltage inputs, apply rated voltage
for your application.
Step 14. Use the front-panel
METER > Fundamental
function or serial
port METER command to verify that the relay is measuring
the magnitude and phase angle of both voltage and current
correctly, taking into account the relay PTR and CTR settings
and the fact that the quantities are displayed in primary units.
Step 15. If you are using a core-balance current transformer, apply a
single-phase current to the IN terminals. Do not apply voltage.
Step 16. Verify that the relay is measuring the magnitude and phase
angle correctly.
The expected magnitude is (applied current) • (CTRN). The
expected phase angle is zero (0).
Step 17. Verify control input connections. Using the front-panel
MAIN > Targets > Row 17
function, check the control input
status in the relay.
As you apply rated voltage to each input, the position in Row
17 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.
60˚
V
AB
V
CB
PHROT := ABC
60˚
V
AB
V
CB
PHROT := ACB
When setting PHROT := ABC, set angle I
A
= 0˚
set angle I
B
= —120˚
set angle I
C
= 120˚
set angle V
AB
= +30˚
set angle V
CB
= +90˚
When setting PHROT := ACB, set angle I
A
= 0˚
set angle I
B
= 120˚
set angle I
C
= —120˚
set angle V
AB
= —30˚
set angle V
CB
= —90˚