15
IZM63 / IN63 low voltage air circuit breaker
MN013014EN May 2021 www.eaton.com.cn
Section 3: Circuit breaker description and operation
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Primary disconnect finger cluster
Arc chamber
Tripper bar
Levering device bearing plate
Padlockable levering device access door
Circuit breaker nameplate
Baffled arc chute cover
Secondary disconnects (contacts)
Faceplate (front cover)
Drawout rail supports
Integral lifting handle
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Figure 3-1 Typical double-wide drawout circuit breaker features (front and rear views)
Section 3: Circuit breaker description and
operation
3-1 Introduction
IZM63 / IN63 circuit breakers are available in two physical
frame sizes and in both drawout and fixed mounting config-
urations (Figure 3-1 and Figure 3-2). A majority of features
are common to both configurations, and will be discussed
in this section. The mounting features unique to the drawout
and the fixed configurations will be covered individually in
Sections 4 and 5 respectively.
Controls and indicators for both drawout and fixed circuit
breakers are functionally grouped on the front of the circuit
breaker. The front escutcheon (faceplate) covers all
continuous current ratings through 6300A.
Double-wide frame circuit breakers use six (or eight) sets of
rear primary connections; these circuit breakers are available
from the factory with several different phase sequences.
The phase sequence is also labeled on the rear of the circuit
breaker (Figure 3-3). For drawout breakers, phase sequence
labels are also supplied with the cassette and must be
applied by the switchgear builder. Circuit breakers with dif-
ferent phase sequences are not interchangeable. Drawout
breakers with differing phase sequence are prevented from
insertion into the cassette by properly assembled rejection
key plates (see Section 2-6.1).