10-26
Testing and Troubleshooting
Date Code 20020129
SEL-387E Instruction Manual
Step 7.
Purpose: Repeat the test for each phase for each winding if desired.
Method: Repeat Steps 1 through 6 for each phase. Remember to view the
appropriate TARGET and apply currents to the appropriate windings.
The computer terminal will display the LED labels from left to right when
the
TAR F
command is issued.
Note:
IRS1 must be greater than
P
087
•
1
SLP
100
if SLP2 is not set to OFF.
SLP2 Restrained Differential Threshold
Step 1.
Purpose: Verify the differential characteristic settings and set winding
compensation.
Method: Execute
the
SHO TAP1<ENTER>
command via the relay front panel or
serial port and verify the (TAPn) settings, the Restraint Slope 1
Percentage (SLP1) setting, the Restraint Slope 2 Percentage (SLP2)
setting, and the restraint current slope 1 limit (IRS1) setting.
Execute the
SET W1CTC<ENTER>
command and set the WnCTC
settings for the two windings to be used to the same value. Save the
settings.
Note:
For this test, use only WnCTC=0 or WnCTC= an odd numbered setting
(1, 3, 5, 7, 9, 11). Depending on the value of IRT selected in Step 3
below, the even-numbered settings may produce 87R outputs from 87R-2
and 87R-3 before the calculated slope 2 current (below) reaches the curve
value for 87R-1. This could lead to erroneous conclusions about the
accuracy of the 87R elements.
Step 2.
Purpose: Display the appropriate Relay Word bit on the front-panel LEDs.
Method: Execute
the
TARGET
command (i.e.,
TAR F 87R<ENTER>
). The
SEL-387E Relay now displays the state of several differential elements in
the second row of the front-panel LEDs. The 87R bit is the right-most
LED.