3.2 Operating Environment
The motor control center conforms with the provisions of
NEMA Standard ICS1-108, Altitude Class 2KM which defines
the usual service condition for electromagnetic control. It is
designed for indoor use where the temperature inside the con-
trol center is higher than the ambient temperature. The con-
trol center is capable of carrying its rated load when the ambi-
ent temperature does not exceed 40°C and the altitude does
not exceed 6600 feet above sea level. Where unusual service
conditions exist or where temperature or altitude limitations
are exceeded, the control center construction, ratings, or pro-
tection may require alteration. Some examples of unusual ser-
vice conditions are excessive moisture, vibration, or dust.
3.3 Site Preparation
Installation shall be in accordance with the National Electrical
Code, ANSI, and NFPA 70 Standards. Unless the motor control
center has been designed for unusual service conditions, it
should not be located where it will be exposed to ambient
temperatures above 40°C (104°F), corrosive or explosive
fumes, dust, vapors, dripping or standing water, abnormal
vibration, shock or tilting, or other unusual operating condi-
tions.
The motor control center should be installed in a clean, dry,
heated place with good ventilation and it should be readily
accessible for scheduled maintenance. A flat, level, concrete
surface should be prepared for the mounting site. If the
mounting site is not flat and level, the motor control center
must be shimmed where necessary to prevent distortion of the
structure.
All conduit entering from the bottom should be in place and
stubbed up about two inches above the finished floor level
before installing the control center. Refer to the MCC lead
sheet plan view located in the information packet for specific
conduit area dimensions.
Note:
Conduit should not extend more than 21/2 inches
above the floor surface.
Siemens Energy & Automation, Inc.
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