59
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
Section 6: Inspection And Maintenance
General
WARNING
FAILURE TO INSPECT, CLEAN AND MAINTAIN CIRCUIT BREAKERS
CAN REDUCE EQUIPMENT LIFE OR CAUSE THE EQUIPMENT NOT
TO OPERATE PROPERLY UNDER FAULT CONDITIONS. THIS COULD
RESULT IN EQUIPMENT DAMAGE, BODILY INJURY OR EVEN DEATH.
WARNING
INSPECTION AND MAINTENANCE PROCEDURES SHOULD BE
CARRIED OUT ONLY BY PERSONNEL FAMILIAR WITH THE HAZARDS
ASSOCIATED WITH WORKING ON POWER CIRCUIT BREAKERS.
ADDITIONALLY, THEY SHOULD BECOME FAMILIAR WITH THE
SPECIFICS ASSOCIATED WITH TYPE MAGNUM DS CIRCUIT
BREAKERS AS PRESENTED IN THIS INSTRUCTION BOOK.
Magnum circuit breakers are “Top of the Line” equipment . This
means they are manufactured under a high degree of qual-
ity control, with the best available materials and with a high
degree of tooling for accuracy and parts interchangeability .
Design tests and actual installation experience show them to
have durability well beyond minimum standards requirements .
However, because of the variability of application conditions
and the great dependence placed upon these circuit breakers
for protection and the assurance of service continuity, inspec-
tion and maintenance activities should take place on a regularly
scheduled basis .
Since maintenance of these circuit breakers consists mainly of
keeping them clean, the frequency of scheduled inspection and
maintenance depends to some degree on the cleanliness of
the surroundings . Cleaning and preventive measures are a part
of any good maintenance program . Plant operating and local
conditions can vary to such an extent that the actual schedule
should be tailored to the conditions . When the equipment is
subject to a clean and dry environment, cleaning is not required
as frequently as when the environment is humid with a signifi-
cant amount of dust and other foreign matter .
It is recommended that maintenance record sheets be com-
pleted for the equipment . Careful and accurate documentation
of all maintenance activities provides a valuable historical refer-
ence on equipment condition over time .
General Cleaning Recommendations
Circuit breaker cleaning activities should be a part of an overall
activity that includes the assembly in which the circuit breaker
is installed . Loose dust and dirt can be removed from external
surfaces using an industrial quality vacuum cleaner and/or lint
free cloth . Unless otherwise indicated, never use high pres-
sure blowing air, since dirt or foreign objects can be driven into
areas, such as the breaker mechanism, where additional fric-
tion sources could create problems . Never use a wire brush to
clean any part of the circuit breaker .
When To Inspect
Do not wait for specific scheduled periods to visually inspect
the equipment, if there are earlier opportunities . If possible,
make a visual inspection each time a circuit breaker compart-
ment door is opened, and especially when a circuit breaker is
withdrawn on its compartment extension rails . This preventive
measure could help to avoid future problems .
Industry standards for this type of equipment recommend a
general inspection and lubrication after the number of opera-
tions listed in
Table 12
of this section . This should also be
conducted at the end of the first six months of service, if the
number of operations has not been reached .
Table 12. Inspection Frequency
Breaker Frame Size
Interval
j
(Breaker Cycles)
800 amperes and below
1750
Between 800 and 3000 amperes
500
3000 amperes and above
250
j
Breaker Cycle = one no load open/close operation
After the first inspection, inspect at least once a year . If these
recommended inspections show no maintenance require-
ments, the period may be extended to a more economical
point . Conversely, if the recommended inspection shows, for
instance, a heavy accumulation of dirt or other foreign mat-
ter that might cause mechanical, insulation or other electrical
damage, the inspection and maintenance interval should be
decreased .