GE 339

CHAPTER 7: MAINTENANCE M3 BREAKER MAINTENANCE
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 7–5
M3 Breaker maintenance
NOTE
NOTE:
M3 Breaker Maintenance and associated functions are available only when the switching
device is set to BREAKER.
Figure 7-3: Breaker maintenance menu
Trip coil
The Trip coil monitoring is performed by a built-in voltage monitor on the Form A output
relay: #1 Trip. The voltage monitor is connected across the Form A contact, and effectively
the relay detects healthy current through the circuit. To do that, an external jumper must
be made between terminals “A2” and “A3” for Trip coil monitoring.
As long as the current through the Voltage Monitor is above the threshold of the trickle
currents (see Technical Specification for Form A output relays), the circuit integrity for the
Trip coil is effectively normal. If the Trip coil circuit gets disconnected, or if in general a high
resistance is detected in the circuitry, a Trip alarm will be set and the “ALARM” and
“MAINTENANCE” LEDs will be on.
NOTE
NOTE:
The Coil Monitor feature is not available with 339 INPUT/OUTPUT option ‘R’. Refer to the
Order Codes section to determine if this feature is supported.
.
Example 1: The figure below shows the connections of the breaker trip coil to the relay’s
trip output relay for voltage monitoring of the trip circuit.
NOTE
NOTE:
To monitor the trip coil circuit integrity, use the relay terminals “A2” and “B3” to connect
the Trip coil, and provide a jumper between terminals “A2” and “A3” (voltage monitor).
896860A1.cdr
M3 BKR MAINTENANCE
TRIP COIL
CLOSE COIL
BKR TRIP COUNTER
BREAKER HEALTH
RESET COUNTERS
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