GE 339

CHAPTER 6: SETPOINTS S3 PROTECTION
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 6–93
Phase reversal (47)
The 339 can detect the phase rotation of the three phase voltages. When all three Phase to
Phase Voltages (Vab, Vbc and Vca) are greater than 50% of the Motor Rated Voltage, if the
phase rotation of the three phase voltages is not the same as the Supply Rotation setpoint,
and there is no fuse failure, either an alarm or a trip and a Start Inhibit will occur within
100ms.
PATH:
SETPOINTS > S3 PROTECTION > PHASE REVERSAL
PHASE REVERSAL FUNCTION
Range: Disabled, Alarm, Trip
Default: Disabled
For details see Common setpoints
.
Figure 6-40: Phase Reversal Protection logic diagram
Set Dominant
LATCH
S
R
AND
LOGIC OPERAND
PH Rvrsl Inhibit
PH Reversal Trip
LOGIC OPERAND
AND
0.1 s
0
LOGIC OPERAND
PH Reversal Alarm
AND
SETTING
= Disabled
= Trip
Phase Reversal
= Alarm
Fuse Fail
LOGIC OPERAND
Phase Reversed
Vbc
SETTING
Supply Rotation
Vca
Vab
AND
AND
AND
INPUTS
Emergency Restart Input
Lockout Reset Input
SETTINGS
Off=0
Lockout Reset
Off=0
Emergency Restart
S4 CONTROLS
Reset Input
Reset
Off=0
AND
OR
KEYPAD RESET
TARGET MESSAGE
PH Reversal Alarm
State: Operate
PH Reversal Trip
State: Operate
896838.cdr
ACTUAL VALUE
Vab > 50% x Rated
Vbc > 50% x Rated
Vca > 50% x Rated
AND
Running
MOTOR STATUS
Any Alarm Op
Any Trip Op
Any Start Inhibit