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

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13 I N S TA L L AT I O N , O P ER AT I O N S A N D M A I N T EN A N C E M A N UA L
Each vertical section accommodates up to 12 X 6E
(480V) or 6 X 12E (600V) total unit height.
The combination of the numeric section code (1, 2,
3 etc.) with the alphabetic 2E height code (A, B, C,
etc.) uniquely describes each unit’s location in the
MCC. For example, the unit mounted in the top of
the first section of a lineup would be coded 1-A. A
unit mounted 750 mm (29.52 in) from the top of
the first section would by 1-R.
Fixed units
Fixed units are directly connected to the horizontal
bus bars by bolted connections. These units do not
fit in sections equipped with vertical bus (multi-
function wall). Their connections could be made
using either power cables or rigid bus bars.
Each unit is covered by a hinged door attached to
the section frame and secured for quarter-turn
latches.
The unit may include an operating handle on the
door that is interlocked to the unit door, preventing
the door from being opened unless the circuit
protective device is in the OFF position.
On main incoming fixed units, a barrier is provided
behind the unit door to prevent unintended contact
with live parts. MCC´s equipped with main lugs
only also are provided with a barrier behind the
door to prevent unintended contact with live parts.
Modular fixed units
Incoming main circuit breakers and incoming main
lug-only units may be Modular Fixed type. These
units tap and back feed the vertical bus within the
multi-function wall.
These units are fastened directly to the section
frame and are not readily removable. Modular fixed
units, including motor starter and feeder units, also
tap the multi-function wall via input plugs on the
back of these units. Similar to fixed units, Modular
Fixed units are covered by a hinged door attached
directly to the section frame. Most of these units
are equipped with circuit protective devices, such
as circuit breakers or fused disconnect switches,
and include operating handles interlocked to the
front doors. A barrier behind the door will be
provided where needed to provide protection
from live parts when the door is open.
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10
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11
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10 Fixed-type unit
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11 Modular fixed type