Eaton IZM32 User Manual

53IZM32 / IN32 low voltage air circuit breaker MN013017EN May 2022 www.eaton.com
Section 7: Inspection and maintenance
Figure 7-3 Primary contacts with circuit breaker
open(not used for contact wear inspection)
Figure 7-4 Contact inspection area with circuit breaker
open
Arc chutes fit inside the arc chambers and down over the
primary contacts. Each arc chute is held in place by one top-
inserted screw (Figure 7-1). Begin by removing the arc chute
screws and all three arc chutes. Turn each arc chute upside
down to visually inspect the inside (Figure 7-2).
WARNING
Arc chutes must always be secured properly in place
before a circuit breaker is installed in a circuit breaker
compartment. Failure to do this could result in
equipment damage, bodily injury, or even death.
When the inspections are complete, position each arc
chute down over its respective set of primary contacts, and
secure in place with the screw removed earlier. Torque the
arc chute screws to 4–5 Nm.
7-4.3 Primary contact inspection
With the arc chutes removed, visually inspect each primary
contact structure for signs of wear and/or damage. The
primary contacts with the circuit breaker open can be
viewed by looking directly down into the arc chamber
(Figure 7-3 and Figure 7-4). A contact wear indicator is
provided for each primary contact and indicates whether
or not the contact should be replaced. Inspection of the
contacts using the contact wear indicators is conducted
only with the circuit breaker closed (Figure 7-5).
NOTICE
When making a contact wear inspection, always make the
inspection by looking straight down into the arc chamber for
the proper perspective. Viewing the contact wear area from
an angle could distort the view.
The contact wear indicator is the relative position of the
individual contact fingers to a narrow, side-to-side ledge
inside the arc chamber. The ledge is actually part of the
arc chamber. When the circuit breaker is closed and the
contacts are in good condition, the narrow ledge is covered
by the back end of the contacts. If the back end of the
contacts do not totally cover the ledge, the contacts should
be replaced.
WARNING
Arc chutes must always be secured properly in place
before a circuit breaker is installed in a circuit breaker
compartment. Failure to do this could result in
equipment damage, bodily injury, or even death.
Once the inspection is completed, be sure to put the arc
chutes back to its original place.
Arcing
contact
(Toe)
Integral
arc runner
Stationary
main contact
Moving main
contact
(Side view)
NOTICE
WARNING
WARNING

Eaton IZM32 Specifications

General

Brand	Eaton
Model	IZM32
Category	Circuit breakers
Language	English