GE DGP Series Instruction Manual page 141

4 ACCEPTANCE TESTS
1. Make the following Settings changes:
DIG INP
(2501) SELBKDI1 = NO BLK (0)
VTFF
(2601) VTFF = DISABLE (0) – set for TEST mode only
2. Connect relay as shown in Figure 4–8: STANDARD FUNCTIONAL TEST CONNECTIONS on page 4–26.
3. Set up relay in test mode for the VTFF function; VTFF ON will be displayed on the MMI.
4. Set the voltage inputs to:
VA = 70 V rms ∠0°,
VB = 70 V rms ∠–120°,
VC = 70 V rms ∠–240°.
5. Set the current inputs to:
IAS = 0.5 A rms ∠90°,
IBS = 0.5 A rms ∠–30°,
ICS = 0.5 A rms ∠–150°.
6. Verify that neither the test pickup nor the test trip operates.
7. Decrease the voltage in all three phases to 49 V rms. Verify that test pickup and test trip operate in 12.4 to
13.0 seconds.
Skip this test if your DGP model does not include this function. This function is not available
on DGP***AAA model relays.
NOTE
1. Make the following Settings changes:
51GN
(2803) PICKUP = 0.5 (0.1)
(2804) TIME FAC = 1.0
2. Connect as shown in Figure 4–6: GENERATOR DIFFERENTIAL TEST CONNECTIONS on page 4–19.
3. Set up relay in test mode for the 51GN function; 51GN ON will be displayed on the MMI.
4. Set the current input to: IAR = 0.45 (0.09) A rms. Set the voltage inputs to:
VA = 70 V rms ∠0°,
VB = 70 V rms ∠–120°,
VC = 70V rms ∠–240°.
5. Verify that neither the test pickup nor the test trip operates.
6. Increase the current input to: IAR = 1.5 (0.3) A rms. Verify that test pickup operates immediately, and test
trip operates in 1.30 to 1.45 seconds.
7. Repeat steps 4 and 5, but use 20 (4.0) A rms in step 4, and verify that test pickup operates immediately
and test trip operates in 184 to 204 ms.
GE Power Management
4.7.24 T27: VOLTAGE TRANSFORMER FUSE FAILURE VTFF
4.7.25 T28: TOC GROUND OVERCURRENT 51GN
DGP Digital Generator Protection System
4.7 PROTECTION TESTS
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