Circuit Breaker Alarm Indicator; Alarm Relay Contacts; Alarm Contact Connection - ADC PowerWorx Select Series User Manual

1.9

Circuit Breaker Alarm Indicator

For each bus, the circuit breaker panel has one visual circuit breaker alarm indicator (red LED)
mounted on the front of the panel. The circuit breaker alarm indicator lights if any circuit
breaker on the corresponding bus fails. The circuit breaker alarm indicator stays off if all circuit
breakers on the corresponding bus are operational. Loss of power to either bus will cause the
circuit breaker alarm indicator for the corresponding bus to be off.

1.10 Alarm Relay Contacts

Warning: Use of one bus only on a dual bus panel will result in false alarms for the unused bus.
Power is required on both buses on a dual bus panel for normal operation.
Each bus contains circuitry that operates a set of Form C alarm relay contacts when any circuit
breaker on the bus trips or when input power to the bus is lost. The alarm contacts may be used
to open or close a loop connected to an external alarm system.
Alarm connections are provided though a screw-down barrier terminal strip or a wire wrap pin
terminal block located on the rear side of the circuit breaker panel. During normal operation, the
normally open (NO) contacts remain open and the normally closed (NC) contacts remain
closed. When a circuit breaker trips or power is lost, the NO contacts close creating a
connection from NO to common (C), and the NC contacts open creating an open circuit
between the NC and C contacts. The maximum current rating for each set of alarm relay
contacts (three sets are provided) is 1.0 Amp.

1.11 Alarm Contact Connection

The fuse panel is available with either a screw-down terminal block or wire wrap pin terminal
block for the alarm contact connections.
The screw-down terminal block consists of six 3-48 screw terminals mounted in a barrier type
terminal block (see
centers with a maximum distance between barriers (maximum connecting terminal width) of
0.200 inch (5.080 mm). Two sets of three terminals (labeled NO, C, and NC) are provided for
connection with external alarm systems. The screw-down terminals will accept #16 to #30
AWG copper wire.
The wire wrap pin terminal block consists of nine wire wrap pins mounted in a terminal block.
Three sets of three wire wrap pins (NO, C, NC) are provided for connection with external alarm
systems. The wire wrap pins will accept #22 to #26 AWG copper wire.
Figure 2). The screw terminals are mounted on 0.250 inch (6.350 mm)
ADCP-80-531 • Issue 4 •July 2004
Page 11
© 2006, ADC Telecommunications, Inc.