GE LPS-O Instruction Manual page 148

5.4 MOB TESTING
5.4 MOB TESTING
1. Record the pre-test values of the Protection Settings used for this test.
2. Settings:
OS BLOCKING
(1601) MOBZONE = 0 (Zone 2)
(1603) BLOCKWHAT = 0 (BLKALL)
Z1DISTANCE
(101) Z1PHASE = NO
Z2DISTANCE
(201) Z2PHASE = YES
(205) Z2P_TIME = 1.0 sec.
Z3DISTANCE
(301) Z3PHASE = NO
Z4DISTANCE
(401) Z4PHASE = NO
3. Connect the relay as shown in Figure 5–1: PHASE-TO-PHASE TEST CONNECTIONS on page 5–7 for
5
the appropriate phase under test.
4. Set the relay to test mode 24 (Out of Step Block). The LUI displays the following:
OUT OF STEP BLK ON
5. Set the voltage inputs to the following values:
VA: 75 volts rms ∠0°,
VB: 75 volts rms ∠–120°,
VC: 75 volts rms ∠+120°.
6. Set the fault current, I
TINGS FOR TEST T17. Note that the leading phase angle is 180° out of phase with the line to which it is
shorted.
Table 5–6: FAULT CURRENT PHASE SETTINGS FOR TEST T17
∠I Degrees
–25
–85
7. Set the currents in the faulted phases to 6.7 (1.4) Amps rms. Reduce the voltages of the faulted phases
and check that the A1 contact closes when the voltages are within the limits shown in Table 5–6: FAULT
CURRENT PHASE SETTINGS FOR TEST T17.
8. Reduce the current in the faulted phase to zero.
9. Repeat the test for phases BC and CA
10. If not continuing with out-of-step trip testing, return settings to their pretest values.
5-
20
, to the phase-angle value listed in Table 5–6: FAULT CURRENT PHASE SET-
op
Volts rms
57 to 63
57 to 63
LPS-O Line Protection System
5 FUNCTIONAL TESTS (FACTORY SETTINGS)
5.4.1 T17 – OUT-OF-STEP BLOCK
GE Power Management