Section 3: Circuit Breaker Description And Operation; Introduction - Eaton IZM32 Instruction Manual

Section 3: Circuit breaker description and
operation

3-1 Introduction

IZM32 / IN32 circuit breakers are available in two physical
frame sizes (3 & 4 poles) in both drawout and fixed
mounting configurations (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 4000A.
3
11
1 Baffled arc chute cover
Secondary disconnects (contacts)
2
Faceplate (front cover)
3
Drawout rail supports
4
5 Integral lifting handle
Figure 3-1 Typical drawout circuit breaker features (front and rear views)
1
5
8
4
9
10
IZM32 / IN32 low voltage air circuit breaker MN013017EN May 2022 www.eaton.com

Section 3: Circuit breaker description and operation

3-2 Basic circuit breaker assembly
Primary disconnect finger cluster
6
Arc chamber
7
Tripper bar
8
9 Levering device bearing plate
Padlockable levering device access door
10
11 Circuit breaker nameplate
2
1
5
7
6
4
6
9
15