Section 5: inspection and
maintenance
5-1 General
WARNING
FAILURE TO INSPECT, CLEAN AND MAINTAIN CIRCUIT BREAk-
ERS 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.
CAUTION
INSPECTION AND MAINTENANCE PROCEDURES SHOULD BE CAR-
RIED 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 DSII CIRCUIT BREAkERS AS
PRESENT IN THIS INSTRUCTION BOOk.
Type DSII 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 interchange-
ability. Design tests and actual installation experience show
them to have durability well beyond minimum standards
requirements. All of these factors give the DSII line of break-
ers high reliability. However, because of the variability of ap-
plication conditions 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.
Since maintenance of these breakers consists mainly of
keeping them clean, the frequency of scheduled inspection
and maintenance depends to some degree on the cleanli-
ness of the surroundings. Cleaning and preventive measures
are a part of any good program. Plant operating and local
conditions can vary to such an extent that the actual sched-
ule should be tailored to the conditions. When the equip-
ment is subject to a clean and dry environment, cleaning is
not required as frequently as if the environment is humid
with a significant amount of dust and other foreign matter.
It is recommended that maintenance record sheets be com-
pleted for the equipment. Careful and accurate documenta-
tion of all maintenance activities provides a valuable histori-
cal 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
removed from external surfaces using an industrial qual-
ity 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.
5-3 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 compart-
ment door is opened, and especially when a circuit breaker
is withdrawn on its compartment extension rails. This pre-
ventive 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 Paragraph 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.
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 eco-
nomical 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. Re-
move it barriers and arc chutes. If there is a deposit of dust,
use a vacuum, as previously mentioned, to remove it from
the circuit breaker. Clean compressed air, if available, can
be used to blow dust and dirt away from the arc chutes and
barriers, as long as it is done out of the immediate vicinity of
Effective July 2010
Instructional Book
IB694C694-03
51
eaton corporation
www.eaton.com
