14
M N S - MCC
LO W VO LTAG E M OTO R CO N T R O L C EN T ER
Withdrawable units
These units are designed to allow quick insertion
and removal of feeders, starters and other special
control units without requiring the connection or
disconnection of power or control wiring.
Withdrawable units have special self-connecting
terminal blocks for incoming and outgoing power
and control wiring, eliminating the need to
manually disconnect control and especially power
load terminations when removing a unit from the
MCC. See Fig. 12 (Withdrawable Unit).
Custom control unit
MCC sections may also include custom control
units, whether empty (including a back plate only)
or to be fitted / filled per customer requirement.
Multi-function wall
Made from Ultramid® A3X2G5 (Nylon 66), the multi-
function wall provides IP20 (Ingress Protection)
protection against solid foreign objects 12.5 mm
(0.5 in) and larger. It is an insulating, non-
flammable and non-hygroscopic housing for
the vertical bus. This design provides a degree
of protection from unintended contact. It
encapsulates the vertical bus and acts as an IP20
barrier between the front accessible areas of the
MCC and the horizontal bus bar compartment
behind. It isolates the vertical busses from the
outside and, also, in between. The multi-function
wall has no moving parts, such as moving shutters,
and is maintenance-free.
Removable units are fed through the multi-function
wall. Its design creates a chamber where each of
the unit input plugs reaches the embedded vertical
bus.
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12 Withdrawable unit
A reinforcement, non-insulated bussing system
could be added to the back of the multi-function
wall to increase its rating to 1600A (100kA at 600V).
Wireways
Vertical wireway
The vertical wireway is provided in all sections that
house removable units. The wireway is located on
the right side of the section, extending the full
height of the structure. It is used for top or bottom
incoming power and control wires terminating into
the individual units within the section.
The standard width of the vertical wireway is 100
mm (3.94 in). An optional 200 mm (7.87 in) wide
wireway is available to provide additional working
space. It increases the overall width of the section
from 500 mm (19.7 in) to 600 mm (23.6 in).
The overall depth of a standard vertical wireway is
292 mm (11.5 in). The wireway includes connection
points on the walls to support and secure wiring
and cables.
The wireway has a full-height, hinged, 14-gauge
steel door secured by three, quarter-turn latches.
The vertical wireway door swings open 105°
opposite of the unit doors for maximum
accessibility (hinge on the right-hand side
of the section frame).
To facilitate cable installation and improve
accessibility in the wireway, the adjacent unit
can be withdrawn from the cubical. If units are
removed, ensure that they are properly marked,
handled and stored. See 2.3.4. Section - Temporary
Storage in this manual.
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12
Rotary handle
inside mechanism
Rotary handle
Unit locking wheel
Unit input plug
Control terminal
block plug part
Control terminal
block socket part
Power cable
connection
socket part
Door‘s interlock
shaft
Unit mechanical
latch
Unit pull handle
