GE 339

CHAPTER 6: SETPOINTS S3 PROTECTION
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 6–89
Figure 6-38: Overfrequency logic diagram
SETTING
OVERFREQ FUNC Disabled = 0
Latched Alarm Alarm
Trip
SETTING
BLOCK 1: Off = 0 BLOCK 2: Off = 0 BLOCK 3: Off = 0
OVERFREQ ALARM PKP
S R
LATCH
LOGIC OPERAND
OVERFREQ ALARM OP
LOGIC OPERAND
OR
OR
AND
AND
AND
AND
OR
AND
AND
INPUTS
Emergency Restart Input Lockout Reset Input
SETTINGS
Off = 0 Lockout Reset Off = 0
Emergency Restart
S4 CONTROLS
OVERFREQ State: Operate
Alarm
TARGET MESSAGE
ANY ALARM OP
OVERFREQ TRIP OP
ANY TRIP OP
S R
LATCH
OVERFREQ Trip State: Operate
TARGET MESSAGE
ANY ALARM PKP OVERFREQ TRIP PKP ANY TRIP PKP
AND AND
OR
S3 OVERFREQUENCY
S3 OVERFREQUENCY
OR
Reset Input
Reset Off = 0
AND
OR
KEYPAD RESET
ANY LATCHED ALARM OP
OVERFREQ State: Pickup
Alarm
TARGET MESSAGE
OVERFREQ State: Pickup
Trip
S3 OVERFREQUENCY
Vab
OVERFREQ PICKUP:
RUN
Van
f > PICKUP
DeltaWye
896836A1.cdr
SETTING
Phase Voltage Inputs (associated setpoints)
SETTING
OVERFREQ DELAY
t
PKP
S3 OVERFREQUENCY
Van < 0.3 x VT
Frequency Measurement
Wye-connected VT: Van Delta-connected VT: Vab
OUTPUT RELAY X
SETTING
Do Not Operate, Operate