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26
Maintenance
Low Voltage Arc Resistant Switchgear (LVSWGR-AR
®
)
Equipped with Magnum DS Circuit Breakers
01.4IB.26263B
12) Breaker Maintenance Cover
When the breaker is temporarily removed
from the compartment for service, install
the removable breaker maintenance
cover to block the opening in the
door. The breaker maintenance cover
must be installed from the inside of the
compartment.
a. Open circuit breaker compartment
door.
b. Unlatch the (4) snap-down arm latches
on the removable breaker maintenance
cover.
c. Insert the removable breaker
maintenance cover from inside of
the compartment door through the
escutcheon seal with metal side of cover
facing toward inside of compartment.
d. Fasten the (4) snap-down arm latches to
secure cover to compartment door.
e. Close and latch compartment door.
The arc resistant rating is only valid when
all doors are closed and properly latched or
bolted, and components are installed and
working properly. In addition, removal of
any breaker from its compartment without
reinstalling a breaker maintenance cover will
void the arc resistant rating.
!
DANGER
13) Records
The condition of each switchgear unit at
the time of inspection should be listed in
a permanent record to become a guide
for anticipating the need for replacements
or for special attention between the
regularly maintenance periods. Insulation
resistance tests are suggested for checking
the insulation. A series of these tests will
indicate any tendency toward a reduction
in dielectric strength of the insulation.
Insulation resistance readings should
be taken before and after cleaning the
equipment and, insofar as possible, under
similar conditions at successive periods.
Records should include the insulation
resistance reading, the temperature, and
the humidity, either by definite reading or
description. Acceptable limits vary with
the extent and design of the bus structure.
In contrast to a small installation, the
longer switchgear assemblies have a more
extensive bus structure with a greater
number of insulators. Therefore, there
are a larger number of parallel insulation
resistance paths to ground, which tends
to decrease insulation resistance readings.
This variation in insulation resistance
between different switchgear assemblies
emphasizes the value of a series of readings
which can be charted to establish a
normal insulation level so that progressive
weakening of the insulation can be
recognized.
