I.
B.
694C694-02
SECTION
5:
INSPECTION AND
MAINTENANCE
5-1
GENERAL
A
WARNING
FAILURE TO INSPECT, CLEAN AND MAINTAIN CIR-
CUIT BREAKERS CAN REDUCE EQUIPMENT LIFE
OR CAUSE THE EQUIPMENT NOT TO OPERATE
PROPERLY UNDER FAULT CONDITIONS, WHICH
COULD RESULT IN EQUIPMENT DAMAGE AND/OR
BODILY INJURY.
A
CAUTION
INSPECTION AND MAINTENANCE PROCEDURES
SHOULD BE CARRIED OUT ONLY BY PERSONNEL
FAMILIAR WITH THE HAZARDS ASSOCIATED WITH
WORKING ON POWER CIRCUIT BREAKERS. ADDI-
TIONALLY, THEY SHOULD BECOME FAMILIAR
WITH THE SPECIFICS ASSOCIATED WITH TYPE
DSll CIRCUIT BREAKERS AS PRESENT IN THIS
INSTRUCTION BOOK.
Type
DS~I
Circuit Breakers are "Top of the Line" equip-
ment. This means they are manufactured under a high
degree of quality control, with the best available materi-
als
a~d
with a high
~~gree
of tooling for accuracy and
parts interchangeability. Design tests and actual installa-
tion experience show them to have durability well
beyond minimum standards requirements. All of these
factors give the DSll line of breakers high reliability.
However, because of the variability of application condi-
tions and the great dependence placed upon these
breakers for protection and the assurance of service
continuity, inspection and maintenance activities should
take place on a regularly scheduled basis.
Sine~
maintenance of these breakers consists mainly of
keeping them clean, the frequency of scheduled inspec-
tion
a~d
maintenance depends to some degree on the
~leanhness
of the surroundings. Cleaning and preven-
tive
m~asures
are a part of any good 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 fre-
quently as if the environment is humid with a significant
amount of dust and other foreign matter.
Effective
07
/97
Page
45
It is recommended that maintenance record sheets be
completed for the equipment. Careful and accurate doc-
umentation of all maintenance activities provides a valu-
able historical reference on equipment condition over
time.
5-2 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
~emoved
from external surfaces using an industrial qual-
ity vacuum cleaner and/or lint free cloth. Unless other-
wise indicated, never use high pressure 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.
5-3 WHEN TO INSPECT
~o
not wait for
~pecific
scheduled periods to visually
inspec~
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 recom-
mend a general inspection and lubrication after the
number of operations listed
in
Paragraph 6.1 of this sec-
tion. This should also be conducted at the end of the
first six months of service, if the number of operations
has not been reached.
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.
5-4 WHAT TO INSPECT
First withdraw the circuit breaker from its compartment.
Remove it barriers and arc chutes. If there is a deposit
of dust, use a vacuum, as previously mentioned, to
r~m?ve
it.
from the circuit breaker. Clean compressed
air,
1f
available, can be used to blow dust and dirt away
Courtesy of NationalSwitchgear.com
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