ABB MNS-MCC, Инструкция по установке, эксплуатации и обслуживанию

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6
M N S - MCC
LO W VO LTAG E M OTO R CO N T R O L C EN T ER
System overview
The MNS-MCC motor control center consists
of one or more vertical metal cabinets referred
to as “sections.” Each section contains one or
more modular units - fixed, modular fixed or
withdrawable - that are employed to distribute
power to discrete loads, such as motors and other
loads. All MCC sections include top and bottom
horizontal wireways. Sections that house
withdrawable and modular fixed units include
vertical bussing and a vertical wireway on the
right-hand side of the section.
The vertical bus system is rated to 800A (standard)
or up to 1,600A (optional). It´s used to provide
power over the vertical height of the bus. The
vertical bus is embedded in the multi- function wall
(see 1.7. Section - Bus Bar Compartments), which
separates the unit compartments at the front of
the MCC from the horizontal bus at the rear of the
MCC sections. The multi-function wall is provided
with multiple tap points, which are IP20.
Each unit may house a wide variety of power and
logic devices. Units may be either door-closed
withdrawable, modular fixed or fixed-mounted
types. Units feature hinged doors held closed
by one or more quarter-turn latches. If the unit
contains a circuit protective device, such as
a molded-case circuit breaker, motor circuit
protector or fused disconnect switch, a rotary
operating handle on the outside of the unit door
will allow operation of the disconnecting means
from outside of the unit.
Fixed and modular fixed units feature operating
handles that may be padlocked with up to three
padlocks. The operating handle is interlocked
with the disconnecting means within the unit,
preventing the unit door from being opened if the
handle is in the ON position (may be defeated with
the use of a tool), or prevent the door from being
opened if the handle is padlocked in the OFF
position.
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General information and system
description
Withdrawable units feature a multi-position handle
that controls the disconnecting means as well as a
mechanical interlock, preventing the unit from
being withdrawn from the MCC unless the
operating handle is in the Move position and the
disconnecting means is OFF.
A continuous horizontal bus rated from 800 to
4,000 amps, distributes incoming power to all MCC
sections. The horizontal bus is located, usually, in
the top half of each section and may be additionally
paralleled with another bus system installed in the
bottom half of the section for higher current rating.
Component names
This manual uses the following naming standards:
• Compartment:
Sections are typically divided in
Equipment Compartment, Vertical Wireway
Compartment and Bus Compartment (See 1.8.
Section - Equipment Compartment).
• Cubicle (or bucket, drawer, module):
The
equipment compartment is sometimes divided
into smaller areas to accommodate units of
different height. One section may be divided into
as many as 12 cubicles.
• Lineup:
The arrangement of several vertical
sections, joined side- by-side, to create a
complete MCC with a continuous horizontal bus.
• Section (or vertical section):
An enclosed vertical
“cabinet” that supports and contains units,
wireways and other internal constructions.
Several sections are typically combined next to
one to another to form a lineup.
• Shipping split:
MCC lineups that include several
vertical sections may be joined side-by-side at
the factory into one or more “shipping splits.”
This facilitates shipping, handling and
installation. Up to three sections may be
combined in a shipping split.
• Unit:
A fixed, modular fixed or withdrawable
electromechanical assembly that is mounted
within a cubicle, e.g. a motor starter or feeder.
• Vertical section:
See 1.9. Section - Wireways.