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R E LI AG E A R LV MCC
LO W VO LTAG E M OTO R CO N T R O L C EN T ER
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Typical top entry of main
cables to the incoming
-line lug compartment
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Typical bottom entry
or main cables to
the incoming-line
lug compartment
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Lorem ipsum
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High heat loss components, including certain solid
state power devices, may require removal of excess
heat to the MCC exterior environment. This is
accomplished by the utilization of exhaust fans
mounted on unit doors along with filters. These
fans and filters are factory installed.
Main incoming power cables
Refer to the motor control center drawings for the
location of the main disconnect or incoming line
terminals and the direction (top or bottom) of
cable entry. Cable-bending room provided within
the vertical section will meet or exceed National
Electrical Code requirements.Incoming line
sections are provided with cable supports.
Incoming cables must be firmly secured to
withstand the significant forces that may
be generated during a short circuit.
Cables secured at each support, as illustrated in
Figure 15B (600A example), will adequately brace
cables for faults of 100K RMS symmetrical
amperes, based on horizontal bus bracing.
However, cables should always be secured at
the first support inside the enclosure and at
the support nearest to the incoming terminals.
Insulated bushings are also recommended at
conduit terminations.
Warning:
The equipment must be adequately
grounded so that all parts of the equipment, other
than live parts, are at ground potential. Failure to
observe this precaution can result in serious injury
or death.
During and after the cable installation, observe the
following rules:
• To prevent heating, avoid closed loops of steel
around a single conductor or group of conductors
that does not include all the conductors of the
circuit, including the neutral.
• If the conductors must pass through separate
holes in a piece of steel, cut slots between the
holes.
• Do not allow cables carrying high currrents to
come near instruments or meters, as this may
affect their accuracy
• Use the minimum length of cable necessary to
make the connections. The increased resistance
of longer cables generaters unnecessary heat
Note:
In addition to using Type 12 exhaust fans and
filters, arc-resistant design will also have a vented
fan shield on the exterior of the door (Figure 13C).
For details on inlet filter maintenance, see Filter
Maintenance on page 33.
NOTICE
WARNING
18/24”
9”
8”
1½”
8”
18/24”
5 wraps
5 wraps (x3)
10 perimeter wraps
Cable lugs
6.0"
max
5 wraps (x2)