GE 345 Quick Start Manual page 38

ELECTRICAL INSTALLATION
NOTE:
OTE
NOTE:
OTE
NOTE:
OTE
32
Breaker monitoring (Trip coil monitoring) is performed by a built-in voltage monitor on
Form A output relays: #1 Trip, and #2 Trip. The voltage monitor is connected across each of
the two Form A contacts, and the relay effectively detects healthy current through the
circuit. In order to do this, an external jumper must be connected between terminals A2
and A3 for #1 Trip coil monitoring, or/and B4, and B5 for #2 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.
Example 1: The figures below show the two different connections of the breaker Trip coil to
the relay's trip output #1 terminals (output #2 Trip coil monitoring) for both no voltage
monitoring and voltage monitoring of the trip circuit integrity.
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 (optional voltage) and A3.
To monitor the Trip coil circuit integrity, use the relay terminals B4 and A4 to connect the
Trip coil, and provide a jumper between terminals B4 (optional voltage) and B5.
Figure 2-20: Relay #1 Trip and Relay #2 Trip circuits with no voltage monitoring
Output Relay 1 (TRIP)
A2
B3
V
A3
897785.cdr
All AUX contacts are shown when the breaker is open.
DC +
Output Relay 2 (TRIP)
52a
contact
Trip
Coil
DC -
345 TRANSFORMER PROTECTION SYSTEM – QUICKSTART GUIDE
CHAPTER 2: INSTALLATION
DC +
B4
A4
V
B5
52a
contact
Trip
Coil
DC -