GE MI-869 - Page 289

CHAPTER 4: SETPOINTS PROTECTION
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 4–171
Figure 4-57: Undercurrent logic diagram
8940$1.cdr
Three Phase Currents
from J1-CT bank
Ia Ib
Ic
SETPOINT
Configurable Trip Function
Disabled Trip
Motor Stopped
FLEXLOGIC OPERAND
SETPOINT
Block
Off=0
AND
Start Block Delay
SETPOINT
t
BLK
0
SETPOINT
Latched Alarm Alarm Function
Disabled
Alarm
OR
AND
RUN
Trip Pickup
SETPOINT
Trip Pickup Delay
SETPOINTS
Trip Dropout Delay
t
PKP
t
RST
Alarm Pickup Delay
SETPOINTS
Alarm Dropout Delay
t
PKP
t
RST
AND
Operate Output
Relay 1(TRIP)
LED: TRIP
LED: Alarm
AND AND
OR
LATCH
S R
RESET
Command
Spd2 U/C Alm PKP
FLEXLOGIC OPERANDS
Spd2 U/C Alm OP
SETPOINT
Trip Output Relay X
Do Not Operate, Operate
SETPOINT
Alarm Output Relay X
Do Not Operate, Operate
OR
I
c
< Trip Pickup
I
b
< Trip Pickup
I
a
< Trip Pickup
OR
RUN
Alarm Pickup
SETPOINT
I
c
< Alarm Pickup
I
b
< Alarm Pickup
I
a
< Alarm Pickup
OR
Setpoints/System/Motor 2-Speed Motor Protection
Disabled = 0
FLEXLOGIC OPERAND
Speed2 Motor Switch
AND
From Setpoint > Protection > Motor > Undercurrent From Setpoint > System > Motor > Setup From Setpoint > Protection > Motor > Undercurrent
Programmed under Setpoint > Protection > Motor > Undercurrent Programmed under Setpoint > Protection > Motor > Undercurrent
Spd2 U/C PKP
FLEXLOGIC OPERANDS
Spd2 U/C OP