GE 339

CHAPTER 6: SETPOINTS S4 CONTROLS
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 6–141
Figure 6-57: Fuse Fail Protection logic diagram
896837A1.cdr
Set Dominant
LATCH
S
R
AND
LOGIC OPERAND
Fuse Fail Inhibit
Fuse Fail Trip OP
LOGIC OPERAND
AND
LOGIC OPERAND
Fuse Fail
OR
Running
MOTOR STATUS
AND
OR
1s
0
LOGIC OPERAND
Fuse Fail Alarm OP
AND
SETTING
= Disabled
= Trip
Fuse Fail Function
= Alarm
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
Fuse Fail Alarm
State: Operate
Fuse Fail Trip
State: Operate
Any Alarm OP
Any Trip OP
Any Start Inhibit
VOLTAGE INPUTS
VOLTAGE INPUTS
< 70%V
a
V
ab
( )
< 70%V
b
V
bc
( )
< 70%V
c
V
ca
( )
>85%V
a
V
ab
( )
>85%V
b
V
bc
( )
>85%V
c
V
ca
( )
V
a
NOTE: The VTFF uses phase to neutral voltages , and when “Wye” VT type is selected under Voltage Sensing/VT connection setpoint, and uses
phase-phase voltages , and when “Delta” type is selected comparators.
V
b
V
c
V
ab
V
bc
V
ca