GE 889 - Page 501

CHAPTER 4: SETPOINTS CONTROL
889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL 4–371
Figure 4-154: VT Fuse Failure logic diagram
894151A1.CDR
COMPARATORS
V_2
SETPOINT
FUNCTION: Disabled Alarm
OR
OR
AND
Latched Alarm
V_2 > 0.10 p.u.
RUN
LED: ALARM /
LATCHED ALARM
RESET
Command
AND
S R
LATCH # 1
Set-
Dominant
Configurable
FlexLogic Operands
VT Fuse Fail 1 OP VT Fuse 1 V Loss
TIMER
2 cyc
20 cyc
SETPOINTS
Do Not Operate, Operate OUTPUT RELAYS 3 to 7
V_1 < 0.05 p.u.
RUN
I_1 > 0.075 p.u.
RUN
V_1 < 0.80 p.u.
RUN
I_1 < 0.05 p.u.
RUN
V_1 I_1
AND
OR
AND
AND
OR
S R S R
LATCH # 2
Reset-
Dominant
LATCH # 3
Reset-
Dominant
AND AND AND
OR
J1 50DD OP
ANDANDAND
OR
FUSE
FAILURE
FAULT
FlexLogic Operand