32
M N S - MCC
LO W VO LTAG E M OTO R CO N T R O L C EN T ER
Locate conduit approximately 50 mm (2 in) above
floor level.
Caution:
Make sure all conduit stubs will
clear the ground bus.
For approximate section base dimensions and
ground bus locations, refer to the elevation and
floor plan drawings shipped with the MCC.
Direct connections to main sections, fixed and
modular fixed units
For main sections, as well as fixed and Modular
fixed units, entry space for connections is provided
at the top or bottom of the MCC sections. The
top plates (and bottom plates, if present) are
removable to facilitate installing conduit or making
other modifications. (See section above for more
information).
For modular fixed units, the hinged wireway door
at top and bottom of the wireway allow direct
access to the unit incoming or outgoing lugs.
If present, the horizontal wire railway must be
removed to make connections.
The top and bottom horizontal wireway and the
vertical wireway are dedicated to incoming lines,
load and control wires. The horizontal wireway
enables running control and power wires between
sections. The control cables run vertically in the
vertical wireway at the right side of the vertical
sections and are connected directly to the control
terminal block.
Avoid corners, sharp turns and edges when forming
cables for termination within the MCC. This
reduces the risk of damage to equipment or
weakening of the cable insulation. The cable
manufacturer’s instructions should be followed
in determining the minimum bending radius of
the cables. This will vary with the size and type
of cable involved.
Cable connections to withdrawable units
Warning:
Failure to support cables can cause
potentially hazardous mechanical deformation
of terminals. Use the wire tie retainer holes
provided in the enclosure to secure the cables.
Outgoing power connections and all control wire
connections for withdrawable units are made in the
vertical wireway, and can enter from either the top
or bottom.
Control Terminal Blocks (CTB):
- Each pole on the control terminal block has
three terminals. Two of them are spade-type
connectors and the third is a screw-type termi-
nal.
- Wire range: 18 - 14 AWG stranded copper wire,
rated 10 A/300 V. Ferrules are recommended for
fine-strand wire.
- All control circuits must be connected to the
withdrawable unit through this CTB.
- Torque: 0.8 Nm/7 lbs-in
Power Cable Connection Unit (CCU 40):
- Rated 50 A/600 V.
- Wire range: 14 – 6 AWG, Cu only. 75° C.
- Torque: 6 Nm/52 lbs-in
- Strip length: 12 mm (1/2 in), (tool required: flat-
blade screwdriver).
Power Cable Connection Unit (CCU 300):
- Rated 400 A/600 V.
- Wire range: Accepts ring tongue terminals.
- Torque: 34 Nm/300 lbs-in
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53
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53 Control terminal block
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54 CCU40 & CCU300
power cable
connection unit
CCU40
Plug-In Part
Plug-In Part
CCU300
Socket part
Socket part
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54
