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5.1 MEASURING UNIT TESTS
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
to 0 Amps.
op
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.
<
V
V
op
nominal
5
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
to zero Amps.
op
The overvoltage function is a positive-sequence overvoltage detector with adjustable time delay such that:
RATEDVOLTS
V
=
--------------------------------------- -
op
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.
5-
8
⋅
0.75
=
50.0 V
×
PHOVPICKUP
1.732
LPS-O Line Protection System
5 FUNCTIONAL TESTS (FACTORY SETTINGS)
5.1.10 T9 – UNDERVOLTAGE TEST
5.1.11 T10 – OVERVOLTAGE TEST
115 V
×
1.10 p.u. V
73.0 V
=
--------------- -
=
1.732
GE Power Management
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