Fixed Circuit Breaker; Circuit Breaker Operation - Eaton Magnum Air MWN-408 User Manual

Figure 2-10: Levering Position Indication
2.8

Fixed circuit breaker

The Magnum fixed type circuit breaker differs from the
drawout version in that it has no levering device, primary
disconnects and secondary disconnects (Figure 2-11). 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 (which is mounted
through the front panel) or with optional cable interlocks
which 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 which are used to bolt the circuit breaker
securely in place. Use either M10 or 3/8" bolts for this
purpose. Refer to the dimensional drawings refered to in
Section 5 (Fixed Circuit Breakers) for circuit breaker and
bus stab dimensions.
1812.900A
Figure 2-11: Typical Fixed Magnum Circuit Breaker
1. Mounting Foot
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 start-up. To check circuit breaker operation,
follow the operational procedures outlined in Section 3 for
both manually operated and electrically operated circuit
breakers.
Magnum
NOTICE
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