GE Industrial Solutions AKD-20 Low Voltage Switchgear - Manuel (Page 54)

AKD-20 Low-voltage Switchgear
Chapter 7. Operating the Switchgear
54 ©2012 General Electric All Rights Reserved
Circuit Breaker Key Interlock
General
A circuit breaker key interlock is available to provide protection
against unauthorized operation. See Fig. 7-5. The key interlock is
mounted on the right of escutcheon of the cassette below the
breaker.
The typical interlock system is designed so that the key may be
removed from the lock only when the breaker is tripped. The key
actuates a cam that elevates the trip bar on the cassette and the
breaker is rendered trip free.
Key Interlock Operation Check
The operation of the key interlock should be checked as follows:
1. With the breaker in the CONNECT position, manually trip the
breaker. This then allows the key interlock to elevate the trip
bar. When the trip bar is elevated, the breaker cannot be
closed but the key can be removed. The breaker will remain
trip free until the key is returned and the trip bar is lowered.
Fig. 7-5. View showing circuit breaker key interlock to
provide protection against unauthorized operation
2. If desired, the breaker may be moved to either the TEST or
DISCONNECT position while the key is removed from the
lock. In these positions, the breaker cannot be operated for
checking or maintenance.
Padlocking the Cassette Racking Door (See Fig. 7-6)
The cassette racking door can be padlocked to prevent access to
the racking door. The cassette can be padlocked with the breaker
in any position or without the breaker installed. Up to three
padlocks can be placed on a cassette. A padlock with a hasp
thickness of at least 0.120” should be used to padlock the racking
shaft door. To padlock cassette racking door, pull out the racking
door locking tab and insert padlock, see Fig 7-6.
Fig. 7-6. Cassette Racking door padlock device
Fig. 7-7. Compartment padlock device
Padlocking the Entelliguard G Cassette (See Fig. 7-7.)
1. The circuit breaker compartment door must be opened to
put the padlock on; however, there is no interference with
the door after the padlock has been placed in position.
2. Padlocks will prevent the acceptance of breakers in the
cassette.
3. The padlock device on the cassette will accept up to three
padlocks on both the left and right sides of the cassette.