IEEE C2-2023

Switchgear assemblies
A. General requirements for all switchgear
To minimize movement, all switchgear shall be secured in a manner consistent with conditions
of service and applicable manufacturer’s instructions.
Cable routed to switchgear shall be supported to minimize forces applied to conductor
terminals.
Piping containing liquids, or corrosive or hazardous gases, shall not be routed in the vicinity of
switchgear unless suitable barriers are installed to protect the switchgear from damage in the
event of a pipe failure.
Switchgear shall not be located where foreign flammable or corrosive gases or liquids routinely
and normally are discharged. Companion equipment such as transformers and switchgear are
not considered foreign.
Switchgear should not be installed in a location that is still specifically under active
construction, especially where welding and burning are required directly overhead. Special
precautions should be observed to minimize impingement of slag, metal filings, moisture, dust,
or hot particles.
EXCEPTION: Switchgear may be installed in a general construction area if suitable temporary protection
is provided to minimize the risks associated with general construction activities.
Precautions shall be taken to protect energized switchgear from damage when maintenance is
performed in the area.
Switchgear enclosure surfaces shall not be used as physical support for any item unless
specifically designed for that purpose.
Enclosure interiors shall not be used as storage areas unless specifically designed for that
purpose.
Metal instrument cases shall be effectively grounded and enclosed in covers that are metal and
effectively grounded, or are of insulating material.
B. Metal-enclosed power switchgear
Switchgear shall not be located within 25 ft (7.6 m) horizontally indoors or 10 ft (3.0 m)
outdoors of storage containers, vessels, utilization equipment, or devices containing flammable
liquids or gases.
EXCEPTION: If an intervening barrier, designed to mitigate the potential effects of flammable liquids or
gases, is installed, the distances listed above do not apply.
NOTE: Rule 180B1 is not intended to apply to the power transformer(s) supplying the switchgear.
Enclosed switchgear rooms shall have at least two means of egress, one at each extreme of the
area, not necessarily in opposite walls. Doors shall swing out and be equipped with panic bars,
pressure plates, or other devices that are normally latched but open under simple pressure.
EXCEPTION: One door may be used when required by physical limitations if means are provided for
unhampered exit during emergencies.
Space shall be maintained in front of switchgear to allow breakers to be removed and turned
without obstruction.
Space shall be maintained in the rear of the switchgear to allow for door opening to at least
90 degrees open, or a minimum of 3 ft (900 mm) without obstruction when removable panels
are used.
Permanently mounted devices, panelboards, etc., located on the walls shall not encroach on the
space requirements in Rule 180B4.
180 180B5
Part 1: Safety Rules for Electric Supply Stations
69
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6. Where columns extend into the room beyond the wall surface, the face of the column shall not
encroach on the space requirements in Rule 180B4.
7. Low-voltage cables or conductors, except those to be connected to equipment within the
compartments rated greater than 1000 V, shall not be routed through the divisions of
switchgear unless installed in rigid metal duct, conduit or isolated by rigid metal barriers.
8. Low-voltage conductors routed from sections rated greater than 1000 V of switchgear shall
terminate in a low-voltage section before being routed external to the switchgear.
9. Conductors entering switchgear shall be insulated for the highest operating voltage in that
compartment or be separated from insulated conductors of other voltage ratings.
10. Switchgear enclosures shall be suitable for the environment in which they are installed.
11. A safety sign shall be placed in each cubicle containing more than one source (greater than
1000 V).
NOTE: ANSI Z535.1-2011, ANSI Z535.2-2011, ANSI Z535.3-2011, ANSI Z535.4-2011, and ANSI
Z535.5-2011 contain information regarding safety signs.
12. The location of control devices shall be readily accessible to personnel. Instruments, relays, and
other devices requiring reading or adjustments should be so placed that work can readily be
performed from the working space.
C. Dead-front power switchboards
Dead-front power switchboards with uninsulated rear connections shall be installed in rooms or
spaces that are capable of being locked, with access limited to qualified personnel.
D. Motor control centers
Motor control centers shall not be connected to systems having higher short-circuit capability
than the bus bracing can withstand. Where current-limiting fuses are employed on the source
side of the bus, the bus bracing and breaker-interrupting rating are determined by the peak

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