GE DGP Series, Instruction Manual

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DGP Digital Generator Protection System GE Power Management
4.7 PROTECTION TESTS 4 ACCEPTANCE TESTS
4
4.7.26 T29: UNDERVOLTAGE 27
Skip this test if your DGP model does not include this function. This function is not available
on DGP***AAA model relays.
1. Make the following Settings changes:
27
(2903) PICKUP = 100
(2904) TIME FAC = 1.0
(2905) CURVE # = 1
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 27 function; 27 ON will be displayed on the MMI.
4. Set the voltage inputs to: VA = 70 V rms
∠
0°, VB = 70 V rms
∠
–120°, and VC = 70 V rms
∠
–240°. Verify
that neither the test pickup nor the test trip operates.
5. Decrease the voltage inputs to: VA = 30 V rms
∠
0°, VB = 30 V rms
∠
–120°, and VC = 30 V rms
∠
–240°.
Verify that test pickup operates immediately, and test trip operates in 1.03 to 1.15 seconds.
4.7.27 T30: THIRD HARMONIC NEUTRAL UNDERVOLTAGE 27TN
Skip this test if your DGP model does not include this function. This function is not available
on DGP***AAA and DGP***ABA model relays.
1. Settings:
27TN
(3003) PICKUP = 0.9
(3004) TL20 = 2.0
(3005) FORPWR-L = 10
(3006) FORPWR-H = 20
2. Connect relay as shown in Figure 4–10: STATOR GROUND TEST FOR 27TN FUNCTION on page 4–39.
3. Set up relay in test mode for the 27TN function; 27TN ON will be displayed on the MMI.
4. Set the voltage and current (rms) inputs to:
VA = 80 V
∠
0°, 60 Hz
VN = 1 V
∠
0°, 180 Hz
IAS = 0.1 A
∠
0°, 60 Hz
5. Verify that neither the test pickup nor the test trip operates.
6. Reduce VN to 0 V. Verify that test pickup operates immediately and test trip operates in 2.0 to 2.1 seconds.
7. Change IAS to 0.2 A
∠
0°, 60Hz. Verify that test pickup and test trip do not operate.
8. Change IAS to 0.3 A
∠
0°, 60Hz. Verify that test pickup operates immediately, and test trip operates in 2.0
to 2.1 seconds.
NOTE
NOTE