GE Industrial Solutions AKD-20 Low Voltage Switchgear - Manuel (Page 47)

AKD-20 Low Voltage Switchgear
Chapter 5. Installing and Removing Circuit Breakers
47 ©2012 General Electric All Rights Reserved
5-1 General
Inspection and Preparation of Circuit
Breakers
Before installing, operating, or removing a circuit breaker, refer to
the breaker instruction manual for preparation, inspection, and test.
Check thoroughly for damaged or loose parts and for any dirt or
foreign matter which may be in the breaker. Be sure that a thin film
of GE lubricating grease D6A15A2 is present on primary disconnects
of the switchgear before installing the breaker.
Circuit Breaker Installation
To install a circuit breaker, proceed as follows:
1. Before installing check the contact areas on each primary
disconnect bar or cluster of fingers for foreign matter that may
have accumulated. Clean these areas if necessary. Be sure
that a thin film of GE lubricating grease D6A15A2 covers the
contact areas before putting a breaker in the compartment.
2. Check to see that the breakers match their respective
compartments. Each breaker is assigned a part or mark
number. This number is shown on the breaker sheets of the
summary, the front view drawings, and on the identification
card on the breaker shipping carton. The breaker may also be
identified using the 20 digit catalog number.
3. To locate the breaker in the proper compartment, refer to the
breaker location list on the front view drawing. Find the
proper breaker by the identification card on the breaker
carton. All identical breakers will have the same mark and
catalog number.
Fig. 5-1. Rejection pin mounting used in cassette
Rejection Feature
Drawout breakers of the same type and rating are interchangeable
in their equipment compartments. Drawout breakers of different
frame size, type, or short-circuit rating are intentionally made non-
interchangeable to prevent inserting the wrong type breaker into a
drawout compartment; Unique "rejection hardware" is affixed to
each breaker and its cassette. When the wrong type breaker is
inserted into a compartment, the pins on the breaker and the pins in
the cassette interfere, thus preventing the wrong breaker from being
racked onto the primary stabs.
EXCEPTION: A breaker with a higher short-circuit rating will fit into
a compartment keyed for a lower short-circuit rating. For example,
a GA08H* breaker can be inserted into an GA08N* compartment. A
GA08N* breaker, however, will be rejected by a GA08H*
compartment.
EXCEPTION: Un disjoncteur ayant un calibrage éléve de court-
circuit accomodera un compartiment classifié d’un calibrage
moindre de court-circuit. Par exemple, un disjoncteur GA08H* peut
être inséré dans un comparitment GA08N*. Cependant un
disjoncteur GA08N* sera rejeté d’un compartiment GA08H*.
Figures 5-1 and 5-2 illustrate the rejection pin mounting used in
Entelliguard G cassettes.
Fig. 5-2. Rejection pins used in Entelliguard G compartments