Date Code 20020129
Testing and Troubleshooting
10-35
SEL-387E Instruction Manual
Step 4.
Purpose: Apply balanced three-phase voltage above the setting and reduce one
phase voltage until the appropriate LED illuminates.
Method: Apply balanced three-phase voltages as shown in Figure 10.5, adjusted to
a value above the
27P1P
setting. Reduce one phase voltage until the
27P1
LED illuminates. The voltage should equal the
27P1P
setting
±2 V
and ±5% of setting. Repeat the test for the other two phases.
Step 5.
Purpose: Repeat the test for each phase undervoltage element.
Method: Repeat Steps 1–4 for the
27P2
undervoltage element.
Step 6.
Purpose: Verify the expected phase-to-phase undervoltage pickup setting.
Method: Execute
the
SHOWSET
command via the relay front panel or serial port
and verify the setting (i.e.,
SHO 27PP1<ENTER>
).
Step 7.
Purpose: Display the appropriate Relay Word bit on the front-panel LEDs.
Method: Execute
the
TARGET
command (i.e.,
TAR F 27PP1<ENTER>
). The
SEL-387E Relay now displays the state of the undervoltage elements on
the bottom row of front-panel LEDs.
Step 8.
Purpose: Apply balanced three-phase voltage above the setting and reduce one
phase voltage until the appropriate LED illuminates.
Method: Apply balanced three-phase voltages as shown in Figure 10.5, adjusted to
a value above the
27PP1
setting. Reduce one phase voltage until the
27PP1
LED illuminates. The phase-to-phase voltage should equal the
27PP1
setting ±2 V and ±5% of setting. Repeat the test for the other two
phase-to-phase voltages.
Step 9.
Purpose: Repeat the test for each phase-to-phase undervoltage element.
Method: Repeat Steps 6–8 for the
27PP2
undervoltage element.
Step 10.
Purpose: Verify the expected positive sequence undervoltage pickup setting.
Method: Execute
the
SHOWSET
command via the relay front panel or serial port
and verify the setting (i.e.,
SHO 27V1P<ENTER>
).
Step 11.
Purpose: Display the appropriate Relay Word bit on the front-panel LEDs.
Method: Execute
the
TARGET
command (i.e.,
TAR F 27V1<ENTER>
). The
SEL-387E Relay now displays the state of the undervoltage elements on
the bottom row of front-panel LEDs.