6
Operation and maintenance of
IZM low voltage air circuit breakers
MOELLER
www.moeller.net/de/support
10/09 AWB1230-1605
Effective October 2009
Section 1: Introduction
General information
The IZM air circuit breaker is a fixed or drawout air circuit breaker
design using an electronic tripping system. It is designed and tested
for use at nominal voltages of 380–440 Vac and 500–690 Vac.
IZM circuit breakers are available in physical frame sizes with
continuous current ratings from 800–6300A and interrupting
capacities from 42–150 kA. The physical frame sizes have common
height and depth dimensions, differing only in width (
).
The circuit breaker nameplate provides complete rating information.
All IZM circuit breakers are 100 percent rated, and are built and
tested in an ISO
T
9002 certified facility to applicable IEC standards
(
). In addition, the IZM circuit breaker
carries a full third-party KEMA certification for both short circuit and
endurance test requirements.
IZM circuit breakers use a rigid frame housing of engineered
thermoset composite resins that has high-strength structural
properties, excellent dielectric characteristics, and arc-tracking
resistance.
The drawout IZM circuit breaker is a through-the-door design
having three breaker positions with the compartment door closed
(CONNECT, TEST, DISCONNECT) and one position out of its
compartment on extension rails (REMOVE). The operating
mechanism is a two-step stored energy mechanism, either
manually or electrically operated.
When withdrawn on captive compartment cassette extension rails,
IZM circuit breakers can be inspected, accessory items added, and
minor maintenance performed. The inside of the compartment can
also be inspected with the circuit breaker on its extension rails.
nOTiCE
PLEaSE rEaD anD UnDErSTanD THESE inSTrUCTiOnS BEFOrE
aTTEMPTing TO UnPaCk, inSTaLL, OPEraTE, Or MainTain THiS
EQUiPMEnT. STUDY THE BrEakEr anD iTS MECHaniSM CarEFULLY
BEFOrE aTTEMPTing TO OPEraTE iT On an EnErgiZED CirCUiT.
Warning
iZM CirCUiT BrEakErS SHOULD nOT UnDEr anY CirCUMSTanCES BE
aPPLiED OUTSiDE THEir naMEPLaTE raTingS. OPEraTiOn OUTSiDE OF
THESE raTingS COULD rESULT in DEaTH, BODiLY inJUrY, Or PrOPErTY
DaMagE.
Safety features
IZM circuit breakers and associated drawout equipment are
manufactured with built-in interlocks and safety-related features.
They are provided to reduce hazards to operating personnel and
provide proper operating sequences.
Figure 1. Family of IZM Low Voltage Air Fixed and Drawout Circuit Breakers (800–6300A)
IZM40
IZM97, IZM32, IZME40
IZM93, IZM20
