NEMA code designations for electrical enclosures.
This is a very brief guide only - no responsibility
..... etc.!
The information on this page was downloaded a while ago as a text file,
the page layout is by Roger Greenwood. See the end for credits.
Type 1 - General Purpose
A General purpose enclosure is intended primarily to prevent accidental
contact with the enclosed apparatus. It is suitable for general purpose
applications indoors where it is not exposed to unusual service conditions.
Type 2 - Drip-Tight
A drip-tight enclosure is intended primarily to prevent accidental contact
with the enclosed apparatus and, in addition, is so constructed as to exclude
falling moisture or dirt.
Type 3 - Weatherproof (Weather-Resistant)
A weatherproof enclosure is intended to provide suitable protection against
specified weather hazards. It is suitable for use outdoors.
Type 3R - Rain tight
A rain tight enclosure is intended primarily to meet the requirements for
rain tight (definition No. 7 of appended list) apparatus. It is suitable
for general applications outdoors where sleet-proof construction is not
required.
Type 4 - Watertight
A watertight enclosure is designed to exclude water applied in the form
of a hose stream. It is suitable for application where the apparatus may
be subjected to a stream of water during cleaning operations and the like.
Type 4X - Watertight and Corrosion resistant
Similar to Type 4, but suitable for service in an environment which is
likely to cause corrosion, such as exposure to harsh cleaning agents or
salt water.
Type 5 - Dust-Tight
A dust-tight enclosure is so constructed as to exclude dust.
Type 6 - Submersible
A submersible enclosure is intended to permit the enclosed apparatus to
operate successfully when submerged in water under specified conditions
of pressure and time.
Type 7 (A, B, C, or D)* Hazardous Locations, Class I-Air Break
These enclosures are designed to meet the application requirements of the
National Electrical Code for Class I Hazardous Locations which may be in
effect from time to time. In this type of equipment, the circuit interruption
occurs in air. *The letter or letters following the type number indicates
the particular group or groups of hazardous locations (as defined in the
National Electrical Code) for which the enclosure is designed. The type
designation is incomplete without a suffix letter or letters.
Type 8 (A, B, C, or D)* Hazardous Locations, Class I-Oil Immersed
These enclosures are designed to meet the application requirements of the
National Electrical Code for Class I Hazardous Locations which may be in
effect from time to time. The apparatus is immersed in oil. *The letter
or letters following the type number indicates the particular group or
groups of hazardous locations (as defined in the National Electrical code)
for which the enclosure is designed. The type designation is incomplete
without a suffix letter or letters.
Type 9 (E, F, or G)* Hazardous Locations, Class II
These enclosures are designed to meet the application requirements of the
National Electrical Code for Class II Hazardous Locations which may be
in effect from time to time. *The letter or letters following the type
number indicates the particular group or groups of hazardous locations
(as define in the National Electrical Code) for which the enclosure is
designed. The designation is incomplete without a suffix letter or letters.
Type 10 - Bureau of Mines-Explosion-proof
This enclosure is designed to meet the explosion proof requirements of
the U.S. Bureau of Mines which may be in effect from time to time. It is
suitable for use in gassy coal mines.
Type 11 - Acid- or Fume-Resistant-Oil Immersed
This enclosure provides for the immersion of the apparatus in oil such
that it is suitable for application where the equipment is subject to acid
or other corrosive fumes.
Type 12 - Industrial Use
An industrial use enclosure is designed for use in those industries where
it is desired to exclude such materials as dust, lint, fibers and flyings,
oil seepage or coolant seepage.
Type 13 - Dust-Proof
A dust-proof enclosure is intended primarily to prevent accidental contact
with the enclosed apparatus and, in addition, is so constructed that dust
which may enter will not interfere with the operation of the apparatus.
The construction of the enclosure can be defined only in relation to the
apparatus and to the amount and kind of dust present.
Definitions
Acid-resistant
Acid-resistant means so constructed that it will not be injured readily
by exposure to acid fumes.
Dustproof
Dustproof means so constructed or protected that dust will not interfere
with its successful operation.
Dust-tight
Dust-tight means so constructed that dust will not enter the enclosing
case.
Fume-resistant
Fume-resistant means so constructed that it will not be injured readily
by exposure to the specified fumes.
Moisture-resistant
Moisture-resistant means so constructed or treated that it will not be
injured readily by exposure to a moist atmosphere.
Oil-tight
Oil-tight means so constructed that oil will not enter the enclosing case.
Rain-tight
Rain-tight means so constructed or protected that exposure to a beating
rain will not result in the entrance of water.
Sleetproof
Sleetproof means so constructed or protected that the accumulation of sleet
will not interfere with its successful operation.
Splashproof
Splashproof means so constructed and protected that external splashing
will not interfere with its successful operation.
Submersible
Submersible means so constructed that it will operate successfully when
submerged in water under specified conditions of pressure and time.
Watertight
Water-tight means provided with an enclosing case which will exclude water
applied in the form of a hose stream under specified conditions.
Weatherproof (Outside Exposure)
Weatherproof means so constructed or protected that exposure to the weather
will not interfere with its successful operation.
Thanks to The Graybar Electric Company for the information
upon which this article is based.
Author: Roy A. Anderson,
President The Roy Anderson Company, Inc. (TRACo, Inc.)
1049 Red Bird Rd.
Loveland,
Ohio 45140
Phone: 513-683-7657
Fax: 513-683-7657
E-Mail address: isis@iac.net
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