GE 845 - Page 342

4–214 845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
PROTECTION CHAPTER 4: SETPOINTS
Figure 4-78: Neutral Overvoltage Protection logic diagram
SETPOINTS
3_V0
SETPOINT
FUNCTION: Disabled
Trip
PICKUP:
AND
Operate Output Relay 1 (TRIP)
LED: PICKUP
LED: TRIP
Alarm
OR
OR
AND
Latched Alarm
AND
SETPOINTS
BLOCK : Off = 0
LED: ALARM /
LATCHED ALARM
RESET
Command
AND
S R
LATCH
Configurable
FlexLogic Operands
Neutral OV 1 OP: Neutral OV 1 PKP:
SETPOINTS
PICK-UP DELAY: DROP-OUT DELAY:
t PKP
t RST
Van > 0.85 x VT Vbn > 0.85 x VT Vcn > 0.85 x VT
OR
3_Vo > PICKUP
RUN
CURVE:
SETPOINTS
Do Not Operate, Operate OUTPUT RELAYS 3 to 7
Phase A Voltage (Va) Phase B Voltage (Vb) Phase C Voltage (Vc)
Phase Voltages
SETPOINTS
SIGNAL INPUT:
Ph VT Bank 1-J2
USED ONLY IN 850
894050A2.cdr