10-38
Testing and Troubleshooting
Date Code 20020129
SEL-387E Instruction Manual
Step 5.
Purpose: Verify the Level 1 volts/hertz delay setting.
Method: Execute
the
SHOWSET
command via the relay front panel or serial port
and verify the setting (i.e.,
SHO 24D1D<ENTER>
).
Step 6.
Purpose: Display the appropriate Relay Word bit on the front-panel LEDs.
Method: Execute
the
TARGET
command (i.e.,
TAR F 24DT<ENTER>
). The
SEL-387E Relay now displays the state of the volts/hertz elements on the
bottom row of front-panel LEDs.
Step 7.
Purpose: Apply balanced three-phase voltage and change the voltage until the
appropriate LED illuminates.
Method: Apply balanced three-phase voltages as shown in Figure 10.5. Change the
voltage to a value above the
24D1P
setting. The
24D1T
LED should
illuminate
24D1D
seconds later, ±0.1% of setting ±4.2 ms (at 60 Hz).
Step 8.
Purpose: Verify the Level 2 volts/hertz pickup setting,
24D2P1
.
Method: Execute
the
SHOWSET
command via the relay front panel or serial port
and verify the setting (i.e.,
SHO 24D2P1<ENTER>
).
Step 9.
Purpose: Display the appropriate Relay Word bit on the front-panel LEDs.
Method: Execute
the
TARGET
command (i.e.,
TAR F 24C2<ENTER>
). The
SEL-387E Relay now displays the state of the volts/hertz elements on the
bottom row of front-panel LEDs.
Step 10.
Purpose: Apply balanced three-phase voltage and change the voltage until the
appropriate LED illuminates.
Method: Apply balanced three-phase voltages as shown in Figure 10.5. Change the
voltage to a value above the
24D2P1
setting until the
24C2
LED
illuminates. The
24C2
pickup should be ±1% of setting.
Calculate
pickup voltage as:
NFREQ
•
PTR
•
3
V
•
freq
•
1
P
2
D
24
•
10
V
nom
sec
=
V
sec
= Secondary Voltage (applied)
PTR
= Potential transformer ratio (Setting)
freq
= Frequency (applied)
NFREQ= Nominal Frequency (Setting)
V
nom
= Nominal Voltage in kV (Setting)