GE Multilin G650 Manual page 181

5.4 PROTECTION ELEMENTS
5.4.2.5 I2T CURVES
The following formulas define this type of curves:
where:
t = Operation time in seconds
Dial = multiplier setting
I = Input current
Itap = Current pickup value
T = reset time in seconds
RESET
Table 5–37: TRIPPING TIME IN SECONDS FOR I2T CURVES
DIAL CURRENT (I/ITAP)
1.5
5
0.01 0.444
0.10 4.444
1.00 44.444
10.00 444.444
100.00 4444.444
600.00 26666.667 15000.000 6666.667
5.4.2.6 DEFINITE TIME CURVES
The definite time makes the element trip when the current value is maintained beyond the pickup value during a longer time
period than the set value. The Dial setting allows modifying this time frame from instantaneous to 900 seconds in steps of
10 ms.
5.4.2.7 RECTIFIER TIME CURVES
Rectifier curves are generated from the following formulas:
where:
T = Operation time (in seconds).
TDM = Multiplying factor
I = Input current
I = Pickup current
pickup
T = Reset time (in seconds) assuming a 100% of power capacity and that the reset is activated
reset
5-38
2.0 3.0 4.0
0.250 0.111 0.063
2.500 1.111 0.625
25.000 11.111 6.250
250.000 111.111 62.500
2500.000 1111.111 625.000
3750.000
G650 Generator Protection & Control System
5.0 6.0 7.0
0.040 0.028 0.020
0.400 0.278 0.204
4.000 2.778 2.041
40.000 27.778 20.408
400.000 277.778 204.082
2400.000 1666.667 1224.490
5 SETTINGS
8.0 9.0 10.0
0.016 0.012 0.010
0.156 0.123 0.100
1.563 1.235 1.000
15.625 12.346 10.000
156.250 123.457 100.000
937.500 740.741 600.000
GEK-113285A