GE 239 Instruction Manual page 23

2 INSTALLATION
d) OUTPUT RELAYS
There are 4 output relays each with form C contacts (normally open (NO), normally closed (NC), and
common (COM)). Contact ratings for each relay are identical and are listed in Section 1.4: SPECIFI-
CATIONS. Figure 2–3: TYPICAL WIRING DIAGRAM on page 2–4 shows the state of the relay con-
tacts with no control power applied; that is, the relays are not energized. Relay contact wiring will
depend on how the relay operation is programmed in 6 287387 5(/$<6 (see Section 4.4: S3: OUT-
PUT RELAYS on page 4–13).
Relay contacts must be considered unsafe to touch when the system is energized. If
the relay contacts are required for low voltage accessible applications, it is the cus-
tomer's responsibility to ensure proper insulation levels.
WARNING
• TRIP RELAY (23/24/25): Wiring of the trip relay contacts will depend on whether a breaker or
contactor is the motor tripping device and if failsafe or non-failsafe operation is desired. See pro-
gramming considerations for the trip relay in Section 4.4a) TRIP RELAY on page 4–14.
Contactor: For maximum motor protection, program the trip relay to be failsafe and wire the
contactor to the NO/COM trip relay terminals. When control power is lost to the 239, the con-
tactor will trip to ensure maximum protection. If process considerations are more important
than protection, program non-failsafe and wire the contactor to the NC/COM trip relay termi-
nals. When control power to the 239 is lost, no protection is available and the motor will con-
tinue to run. This has the advantage that the process will not shut down, however the motor
may be damaged if a fault develops under these conditions.
Breaker: Wire the breaker trip coil to the NO/COM trip relay terminals. The breaker auxiliary
52a contact (closed when the breaker is closed) should be wired in series with the trip relay to
break the current to the trip coil as soon as the breaker opens. Program the trip relay as non-
failsafe. Breaker close coil control is not provided by the 239 as it is a protection device. Con-
trol for closing the breaker must be provided externally.
• ALARM RELAY (26/27/28): A selected alarm condition will cause the alarm relay to activate.
Alarms can be disabled for each feature so that only desired conditions cause an alarm. Alarm
conditions that can be programmed to activate the alarm relay are: ground fault, undercurrent,
phase unbalance, overload, RTD 1-3, thermistor, option switch 1, option switch 2, test and loss of
control power (failsafe mode). If an alarm is required when control power is not present, indicat-
ing that protection is not available, select )$,/6$)( operation for the alarm relay using 6 287387
5(/$<6?$/$50 5(/$<?$/$50 23(5$7,21 . Contacts NC/COM will be normally open going to a closed
state on an alarm. Since the service relay gives a fault indication for loss of control power, it may
be preferable to have no alarm on loss of control power and use the service relay for this indica-
tion to distinguish it from a process problem. In this case, wire the external alarm to the NO/COM
terminals which will be normally open going to a closed state on an alarm condition. If 81/$7&+('
mode is selected using setpoint 6 287387 5(/$<6?$/$50 5(/$<?$/$50 $&7,9$7,21 the alarm relay
automatically resets when the alarm condition disappears. For /$7&+(' mode, the
must be pressed (or serial port reset command received) to reset the alarm relay.
• AUXILIARY RELAY (29/30/31): An additional output relay is provided which can be configured
for:
short circuit/ground trip: Contactors are not rated to open under a short circuit. Use this
output to trip the main feeder breaker in the event of a short circuit at the motor. See setpoint
6 3527(&7,21?3+$6( &855(17?3+$6( 6&?3+$6( 6& 75,3 
GE Multilin
Courtesy of NationalSwitchgear.com
239 Motor Protection Relay
2 INSTALLATION
2
RESET key
2-7