M3 Breaker Maintenance; Trip Coil - GE 339 Instruction Manual

CHAPTER 7: MAINTENANCE

M3 Breaker maintenance

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Trip coil

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339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
M3 Breaker Maintenance and associated functions are available only when the switching
device is set to BREAKER.
Figure 7-3: Breaker maintenance menu
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.
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.
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).
M3 BKR MAINTENANCE
TRIP COIL
CLOSE COIL
BKR TRIP COUNTER
BREAKER HEALTH
RESET COUNTERS
896860A1.cdr
M3 BREAKER MAINTENANCE
7–5