The modular design of motor control centers
allows for easy expansion to keep pace with an
expanding electrical system.
When space is available in the existing motor
control center, starter units can easily be added
When no more unit mounting space Is available,
additional vertical sections can be used to provide
Starter units may be rearranged or replaced with
larger units In most cases, a Size I starter unit may
be replaced with a Size 2 starter with no change in
mounting space requirements.
When ordering additional motor control center
equipment, the following information should be
A Type of equipment being supplied
B Supply voltage
C EEMAC enclosure type
D Enclosure finish
E Control circuit voltage
F Optional control circuit components required
(control transformers, push buttons, pilot
lights, selector switches, etc.).
G Any special features
ALWAYS SUPPLY THE SQUARE D FACTORY
ORDER NUMBER OF THE ORIGINAL MOTOR
TROUGH DOOR THE UNIT LABEL INSIDE
EACH CONTROL UNIT ALSO CONTAINS THE
FACTORY ORDER NUMBER.
When new vertical sections are to be supplied,
H Horizontal and vertical bus capacity
I Bus bracing (or available fault current)
J Enclosure dimensions
K Enclosure arrangements
1.Units mounted front only
2 Units mounted front and rear
3 7 space factor construction
4 61 space factor construction.
Installing Additional Motor Control Center Units
WARNING: There is a hazard of electrical shock
or burn whenever working in or around electrical
equipment before working on it.
The following procedure should be followed when
adding units to an existing motor control center E-4
Remove blank cover plate(s) to make room for the
Install unit support pan in structure This will require
partial removal of any unit located directly below
the new units location See unit lockout Procedure
M-12 (padlocking not required), page 17 Disregard
if support pan is already in place.
Install self-retaining door screws into new unit door