Publication 2100-IN012B-EN-P - April 2005
Final Checklist Before Energizing 3-3
4. Check the integrity of the bus splice connections. Recommended torque
values can be found on the information label located on the interior of
the vertical wireway door or on the interior right-hand side plate of
frame mounted units. See publication 2100-IN010x-EN-P, Joining and
Splicing Vertical Sections, for splicing information.
NOTE: The factory-made power bus connections are tightened by a
computer-controlled torquing system. The following connections do not
require re-torquing: vertical to horizontal bus connections and power
conductor to horizontal bus connections. These factory-made horizontal to
vertical bus connections do not require servicing for the life of the MCC.
5. Check and verify that all ground connections are made properly, based
on local standards. If ground bus is not provided or has been removed,
ensure the MCC sections are connected to provide a continuous ground
path.
6. Field Wiring
A. Check the field wiring for proper conductor sizing. MCC field
conductors should be sized using the National Electrical Code
(NEC) 167
o
F (75
o
C) wire tables.
B. Removal of barrier(s) may have been required for field wiring.
Check and ensure that all barriers and parts that may have
been removed during installation have been reinstalled. It is
recommended that a barrier checklist is developed including such
items as, unit location, barrier location, etc. This checklist should be
saved for future reference.
C. Make certain all incoming and outgoing power wiring is secure and
braced to withstand the effects of a fault current as detailed in
Chapter 4. Make sure that conduit and/or cabling are well
supported. For incoming line compartments, 2.0 space factors (26”
[660.4 mm]) or less, the incoming cables should be firmly secured
halfway between the top of the section and the incoming line
compartment terminals. In a full section (6.0 space factor) incoming
line compartments the cables should be braced every 12” (305 mm);
if the system’s available short circuit current is above 42,000 amperes
but less then 65,000 amperes rms symmetrical. Above 65,000
amperes rms symmetrical available current bracing should occur
every 6.5” (165 mm). This bracing is in accordance with the
Underwirters Laboratories (UL) listing and is necessary to withstand
forces resulting from high fault currents. For information on cable
bracing methods, see Chapter 4 of this publication.
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