GE 745 Instruction Manual page 167

CHAPTER 5: SETPOINTS
5.6.7.3 Ground Instantaneous Overcurrent
 
W1 GND [
INST OC 1
Note
NOTE
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
FIGURE 5–20: Ground time overcurrent scheme logic
PATH: SETPOINTS S4 ELEMENTS

] W1 GROUND INST OC 1
FUNCTION: Disabled
W1 GROUND INST OC 1
MESSAGE
RLYS (1-8): --------
W1 GROUND INST OC 1
MESSAGE
TARGET: Latched
W1 GROUND INST OC 1
MESSAGE
PICKUP: 10.00 x CT
W1 GROUND INST OC 1
MESSAGE
DELAY:
W1 GROUND INST OC 1
MESSAGE
BLOCK: Disabled
• W1(3) GROUND INST OC 1(2) PICKUP: Enter the level of ground current (in units of
relay nominal current) above which the winding 1(3) ground instantaneous
overcurrent 1 element will pickup and start the delay timer.
• W1(3) GROUND INST OC 1(2) DELAY: Enter the time that the ground current must
remain above the pickup level before the element operates.
The messages above and scheme logic below are identical for windings 2 and 3 of
ground instantaneous overcurrent 1 and all windings on the ground instantaneous
overcurrent 2 element.
GROUND OC W1(3) GROUND INST OC 1(2)
 
Range:
Range:
Range:
Range:
Range:
0 ms
Range:
S4 ELEMENTS
Enabled, Disabled
1 to 8
Self-Reset, Latched, None
0.05 to 20.00 x CT in steps of
0.01
0 to 60000 ms in steps of 1
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
5–71