11
IZM32 / IN32 low voltage air circuit breaker
MN013017EN May 2022 www.eaton.com
Section 2: Receiving, handling, and installation
Horizontal
connection
Vertical
connection
Mounting
foot
Figure 2-12 Levering position indication
Figure 2-13 Typical fixed circuit breaker
Figure 2-14 Fixed circuit breaker with available vertical
adapter
2-8 Fixed circuit breaker
The fixed-type circuit breaker differs from the drawout
version in that it has no levering device, primary
disconnects, and secondary disconnects (Figure 2-13). In
addition, a fixed circuit breaker does not have a standard
feature to hold the breaker in a trip-free position. Fixed
circuit breakers can be mechanically interlocked using either
the optional key interlock (that is mounted through the front
panel) or with optional cable interlocks that operate on the
tripper bar (Figure 3-1).
Circuit breaker terminals have holes for making bolted
horizontal primary bus connections. Adapters are available
for making vertical primary bus connections. Secondary
connections can be made through standard terminal blocks
or a special connector compatible with the drawout circuit
breaker’s type secondary connector. Both secondary
connection devices are mounted at the top front of the
circuit breaker.
The fixed circuit breaker frame has two mounting feet,
one on each side, to permit the fixed circuit breaker to be
securely mounted. Each mounting foot has two slotted
mounting holes that are used to bolt the circuit breaker
securely in place. Use either M10 or 3/8-inch bolts for this
purpose. Refer to the dimensional drawings referred to in
Section 4 “Fixed circuit breakers” for circuit breaker and bus
stab dimensions.
NOTICE
Refer to the circuit breaker weights in table 2-1 to ensure
that the panel on which a fixed circuit breaker is to be
mounted is capable of supporting the weight.
2-9 Circuit breaker operation
Circuit breakers should be operated manually and/or
electrically before they are put into service. This can be
done during the installation process or some later date
prior to startup. To check circuit breaker operation, follow
the operational procedures outlined in Section 3 for both
manually operated and electrically operated circuit breakers.
Fixed circuit breaker dimensions
The standard fixed circuit breaker is supplied with
horizontally mounted primary connections (Figure 2-14).
Optional vertical primary adapters are available for different
bus configurations.
NOTICE
