Inspection And Maintenance; General; General Cleaning Recommendations; When To Inspect - Eaton Magnum Air MWN-408 User Manual

Magnum

6 INSPECTION AND MAINTENANCE

6.1

General

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.
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 quality 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,
inspection 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.
46
WARNING
CAUTION
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 significant amount
of dust and other foreign matter.
It is recommended that maintenance record sheets be
completed for the equipment. Careful and accurate
documentation of all maintenance activities provides a
valuable historical reference on equipment condition over
time.
6.2

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 pressure blowing air, since dirt
or foreign objects can be driven into areas, such as the
breaker mechanism, where additional friction sources
could create problems. Never use a wire brush to clean
any part of the circuit breaker.
6.3

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 compartment 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
operations listed in Table 6-1 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 6-1: Inspection Frequency
Breaker Frame Size
800 amperes and below
Between 800 and 3000 amperes
3000 amperes and above
1
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
requirements, 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 matter that might cause mechanical,
insulation or other electrical damage, the inspection and
maintenance interval should be decreased.
1
Interval (Breaker
Cycles)
1750
500
250
1812.900A