Evolution Series E9000 User Manual
4
General Description –
Arc Resistant
The Arc Resistant sections are built with increased
structural capacity. The main enhancements are thicker
gage of steel, latches, hinges, and metallic PD brackets.
In addition, there are two versions available with and
without a plenum. The plenum option adds 12" to the
top of the 90" section. The plenumless option should
have a 4' clearance on top of the MCC. The top (12"
high) horizontal wireway door and the bottom (6" high)
wireway door utilize multi-turn latches to secure the
doors. The remaining latches are ¼ turn (with options
for closed status indication). There is no variation in the
units between Arc Resistant and standard E9000 other
than the unit door. Additionally, the Arc Flash Mitigation
units are compatible in Arc Resistant design with
Arc Resistant/Arc Flash Mitigation door.
General Description –
Motor Control Center Buses
The main horizontal power bus is located at the top of
the vertical section. The bus bolted joints are accessible
from the front by loosening the barrier mounting screws
and sliding the Lexan
®
bus barrier up and forward from
the main bus. Figure 2 shows a horizontal power bus
with its Lexan barrier. For Arc Resistant design, uses
this same Lexan barrier with additional Metallic dead
front barrier.
The vertical bus, either 300A or 600/850 A, is connected
with two bolts per phase to the main bus. The phase
relationship is A–B–C from top to bottom and left to
right, as viewed from the front.
A continuous horizontal ground bus, sized in accordance
with the National Electrical Code, is provided near the
bottom of all motor control centers.
An optional vertical ground bus can be provided in each
section providing additional grounding. A neutral bus is
provided, when specified, in the bottom of the incoming
section or in the bottom of all enclosure(s) as specified.
As shown in Figure 3, the Arc Resistant MCC will include
a metallic main bus barrier in addition to the standard
Lexan barrier.
General Description –
Motor Control Center Units
Consult Publication DET-291 for detailed listings of
Evolution MCC units.
Plug-in units are supplied with stabs rated at either
250 A or 600 A. Arc Flash Mitigation (AFM) units are
supplied with retractable stabs, mechanical interlocks,
racking screw, and visual stab and shutter indicators. AFM
units are available in plug-in or stab-bolt configuration.
Installation and operation of units, both standard and
AFM, are described on page 14 of this guide.
Figure 3. Metallic horizontal bus barrier for Arc Resistant design
Figure 2. Horizontal bus with Lexan barrier
