15
Instructional Leaflet
IB2C12063H03
Effective March 2012
Instructions for Installation, Operation and
Maintenance of Magnum SB Insulated Case
Low Voltage Power Circuit Breakers
EATON CORPORATION
www.eaton.com
CONNECT
TEST
DISCONNECT
CONNECT
TEST
DISCONNECT
Figure 15. Levering Position Indication
CAUTION
THE CIRCUIT BREAKER MECHANISM IS INTERLOCKED SUCH THAT
CHARGED CLOSING SPRINGS ARE AUTOMATICALLY DISCHARGED
IF THE CIRCUIT BREAKER IS LEVERED INTO OR OUT OF THE CELL.
DISCHARGE TAKES PLACE BETWEEN THE DISCONNECT AND TEST
POSITION.
Fixed Circuit Breaker
Magnum SB fixed type circuit breakers differ from the drawout
version in that it has no levering device, primary disconnects
and secondary contact connector (
Figure 16
) . In addition,
a fixed circuit breaker does not have a standard feature to
hold the breaker in a trip free position . To ensure the proper
sequence of operation between two or more circuit breakers,
an optional key interlock is mounted through the front panel
(
Figure 70
) .
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 .
Mounting Foot
Figure 16. Typical Fixed Magnum SB 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 referred to in
Section 5 (Fixed Circuit
Breakers)
for circuit breaker and bus stab dimensions .
CAUTION
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.
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 at 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 .