5-
8
LPS-O Line Protection System GE Power Management
5.1 MEASURING UNIT TESTS 5 FUNCTIONAL TESTS (FACTORY SETTINGS)
5
5.1.10 T9 – UNDERVOLTAGE TEST
1. The undervoltage function has a fixed pickup setting of 75% of nominal.
2. Connect the relay as shown in Figure 5–1: PHASE-TO-PHASE TEST CONNECTIONS on page 5–7.
3. Set the relay into test mode 32. The LUI displays
UNDERVOLTAGE ON
4. Set the voltage inputs to the following values:
VA: 67 volts rms
∠
0°
VB: 67 volts rms
∠
–120°
VC: 67 volts rms
∠
+120°
5. Set
I
op
to 0 Amps.
6. Set phase A voltage to 40 V and check that contact A1 closed. Set phase A voltage back to 67 V and
check that contact A1 opens. Repeat for phase B and C.
5.1.11 T10 – OVERVOLTAGE TEST
1. Record the pre-test values for Protection Settings 701, 702, 703, and 704.
2. Connect the relay as shown in Figure 5–1: PHASE-TO-PHASE TEST CONNECTIONS on page 5–7.
3. Protection settings:
VOLTAGE
(701)
RATEDVOLTS
= 115 V rms
(702)
PHASEOVER
= YES
(703)
PHOVPICKUP
= 1.10 p.u. V
(704)
PHOVTMDLY
= 0.5 sec.
4. Set the relay into test mode 31. The LUI displays
OVERVOLTAGE ON
5. Set the voltage inputs to the following values:
VA: 67 volts rms
∠
0°
VB: 67 volts rms
∠
–120°
VC: 67 volts rms
∠
+120°.
6. Set
I
op
to zero Amps.
The overvoltage function is a positive-sequence overvoltage detector with adjustable time delay such that:
7. Set phase A voltage to 76 V and check that contact A1 is closed. Set phase A voltage back to 67 V and
check that contact A1 opens. Repeat for phases B and C.
8. Restore these Protection Settings to the values recorded in Step 1.
V
op
V
nominal
0.75
⋅<
50.0 V=
V
op
RATEDVOLTS
1.732
----------------------------------------
PHOVPICKUP
×
115 V
1.732
----------------
1.10 p.u. V
×
73.0 V===