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NEMA_Enclosure_Types

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NEMA_Enclosure_Types

    NEMA Enclosure Types

The purpose of this document is to provide general information on the definitions of

    NEMA Enclosure Types to architects, engineers, installers, inspectors and other

    interested parties. [For more detailed and complete information, NEMA Standards

    Publication 250-2003, “Enclosures for Electrical Equipment (1000 Volts Maximum)

    should be consulted. This Standards Publication as well as all other NEMA

    publications are available from IHS @ 800 854-7179 or http://www.global.ihs.com]

    Definitions

    [from NEMA 250-2003]

    In Non-Hazardous Locations, the specific enclosure Types, their applications, and the environmental conditions they are designed to protect against, when completely and

    properly installed, are as follows:

Type 1 Enclosures constructed for indoor use to provide a degree of protection to

    personnel against access to hazardous parts and to provide a degree of protection of

    the equipment inside the enclosure against ingress of solid foreign objects (falling dirt).

Type 2 Enclosures constructed for indoor use to provide a degree of protection to

    personnel against access to hazardous parts; to provide a degree of protection of the

    equipment inside the enclosure against ingress of solid foreign objects (falling dirt); and

    to provide a degree of protection with respect to harmful effects on the equipment due

    to the ingress of water (dripping and light splashing).

Type 3 Enclosures constructed for either indoor or outdoor use to provide a degree

    of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt and windblown dust); to provide a degree of protection with respect to

    harmful effects on the equipment due to the ingress of water (rain, sleet, snow); and

    that will be undamaged by the external formation of ice on the enclosure.

Type 3R Enclosures constructed for either indoor or outdoor use to provide a degree

    of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt); to provide a degree of protection with respect to harmful effects on the

    equipment due to the ingress of water (rain, sleet, snow); and that will be undamaged

    by the external formation of ice on the enclosure.

    National Electrical Manufacturers Association Approved by NEMA Enclosures Section th1300 N. 17 Street, Suite 1752 Nov 2005

    Rosslyn, VA 22209 Page 1 of 9

    NEMA Enclosure Types

    Type 3S Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt and windblown dust); to provide a degree of protection with respect to

    harmful effects on the equipment due to the ingress of water (rain, sleet, snow); and for

    which the external mechanism(s) remain operable when ice laden.

    Type 3X Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt and windblown dust); to provide a degree of protection with respect to

    harmful effects on the equipment due to the ingress of water (rain, sleet, snow); that

    provides an additional level of protection against corrosion and that will be undamaged

    by the external formation of ice on the enclosure.

    Type 3RX Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt); to provide a degree of protection with respect to harmful effects on the

    equipment due to the ingress of water (rain, sleet, snow); that will be undamaged by the

    external formation of ice on the enclosure that provides an additional level of protection

    against corrosion; and that will be undamaged by the external formation of ice on the

    enclosure.

    Type 3SX Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt and windblown dust); to provide a degree of protection with respect to

    harmful effects on the equipment due to the ingress of water (rain, sleet, snow); that

    provides an additional level of protection against corrosion; and for which the external

    mechanism(s) remain operable when ice laden.

    Type 4 Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt and windblown dust); to provide a degree of protection with respect to

    harmful effects on the equipment due to the ingress of water (rain, sleet, snow,

    splashing water, and hose directed water); and that will be undamaged by the external

    formation of ice on the enclosure.

National Electrical Manufacturers Association Approved by NEMA Enclosures Section

    1300 N. 17th Street, Suite 1752 November 2005

    Rosslyn, VA 22209

    NEMA Enclosure Types

    Type 4X Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (windblown dust); to provide a degree of protection with respect to harmful effects on

    the equipment due to the ingress of water (rain, sleet, snow, splashing water, and hose

    directed water); that provides an additional level of protection against corrosion; and

    that will be undamaged by the external formation of ice on the enclosure.

    Type 5 Enclosures constructed for indoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the

    equipment inside the enclosure against ingress of solid foreign objects (falling dirt and

    settling airborne dust, lint, fibers, and flyings); and to provide a degree of protection

    with respect to harmful effects on the equipment due to the ingress of water (dripping

    and light splashing).

    Type 6 Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt); to provide a degree of protection with respect to harmful effects on the

    equipment due to the ingress of water (hose directed water and the entry of water

    during occasional temporary submersion at a limited depth); and that will be

    undamaged by the external formation of ice on the enclosure.

    Type 6P Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt); to provide a degree of protection with respect to harmful effects on the

    equipment due to the ingress of water (hose directed water and the entry of water

    during prolonged submersion at a limited depth); that provides an additional level of

    protection against corrosion and that will be undamaged by the external formation of

    ice on the enclosure.

    Type 12 Enclosures constructed (without knockouts) for indoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a

    degree of protection of the equipment inside the enclosure against ingress of solid

    foreign objects (falling dirt and circulating dust, lint, fibers, and flyings); and to provide a

    degree of protection with respect to harmful effects on the equipment due to the ingress

    of water (dripping and light splashing).

    Type 12K Enclosures constructed (with knockouts) for indoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of

    protection of the equipment inside the enclosure against ingress of solid foreign objects

    (falling dirt and circulating dust, lint, fibers, and flyings); and to provide a degree of

    National Electrical Manufacturers Association Approved by NEMA Enclosures Section

    1300 N. 17th Street, Suite 1752 November 2005

    Rosslyn, VA 22209

    NEMA Enclosure Types protection with respect to harmful effects on the equipment due to the ingress of water

    (dripping and light splashing).

Type 13 Enclosures constructed for indoor use to provide a degree of protection to

    personnel against access to hazardous parts; to provide a degree of protection of the

    equipment inside the enclosure against ingress of solid foreign objects (falling dirt and

    circulating dust, lint, fibers, and flyings); to provide a degree of protection with respect

    to harmful effects on the equipment due to the ingress of water (dripping and light

    splashing); and to provide a degree of protection against the spraying, splashing, and

    seepage of oil and non-corrosive coolants.

    Table 1

     [From NEMA 250-2003]

    Comparison of Specific Applications of Enclosures

     for Indoor Nonhazardous Locations

     Type of Enclosure Provides a Degree of Protection Against the 1 * 2 * 4 4X 5 6 6P 12 12K 13 Following Conditions

    Access to hazardous parts X X X X X X X X X X Ingress of solid foreign objects (falling dirt) X X X X X X X X X X Ingress of water (Dripping and light splashing) ... X X X X X X X X X Ingress of solid foreign objects (Circulating dust, ... ... X X ... X X X X X lint, fibers, and flyings **)

    Ingress of solid foreign objects (Settling airborne ... ... X X X X X X X X dust, lint, fibers, and flyings **)

    Ingress of water (Hosedown and splashing water) ... ... X X ... X X ... ... ... Oil and coolant seepage ... ... ... .. ... ... ... X X X Oil or coolant spraying and splashing ... ... ... ... ... ... ... ... ... X Corrosive agents ... ... ... X ... ... X ... ... ... Ingress of water (Occasional temporary ... ... ... ... ... X X ... ... ... submersion)

    Ingress of water (Occasional prolonged ... ... ... ... ... ... X ... ... ... submersion)

     * These enclosures may be ventilated. ** These fibers and flyings are nonhazardous materials and are not considered Class III type ignitable fibers or combustible flyings. For Class III type ignitable fibers or combustible flyings see the National Electrical Code, Article 500.

National Electrical Manufacturers Association Approved by NEMA Enclosures Section

    1300 N. 17th Street, Suite 1752 November 2005

    Rosslyn, VA 22209

    NEMA Enclosure Types

    Table 2

     [From NEMA 250-2003]

    Comparison of Specific Applications of Enclosures

     for Outdoor Nonhazardous Locations

    Type of Enclosure Provides a Degree of Protection Against

    the Following Conditions 3 3X 3R* 3RX* 3S 3SX 4 4X 6 6P Access to hazardous parts X X X X X X X X X X

    X X X X X X X X X X Ingress of water (Rain, snow, and sleet **)

    ... ... ... ... X X ... ... ... ... Sleet ***

    Ingress of solid foreign objects (Windblown X X ... ... X X X X X X dust, lint, fibers, and flyings)

    Ingress of water (Hosedown) ... ... ... ... ... ... X X X X Corrosive agents ... X ... X ... X ... X ... X Ingress of water (Occasional temporary ... ... ... ... ... ... ... ... X X submersion)

    Ingress of water (Occasional prolonged ... ... ... ... ... ... ... ... ... X submersion)

    * These enclosures may be ventilated. ** External operating mechanisms are not required to be operable when the enclosure is ice covered. *** External operating mechanisms are operable when the enclosure is ice covered.

    In Hazardous Locations, when completely and properly installed and maintained, Type 7 and 10 enclosures are designed to contain an internal explosion without

    causing an external hazard. Type 8 enclosures are designed to prevent combustion

    through the use of oil-immersed equipment. Type 9 enclosures are designed to

    prevent the ignition of combustible dust.

Type 7 Enclosures constructed for indoor use in hazardous (classified) locations

    classified as Class I, Division 1, Groups A, B, C, or D as defined in NFPA 70.

Type 8 Enclosures constructed for either indoor or outdoor use in hazardous

    (classified) locations classified as Class I, Division 1, Groups A, B, C, and D as defined

    in NFPA 70.

Type 9 Enclosures constructed for indoor use in hazardous (classified) locations

    classified as Class II, Division 1, Groups E, F, or G as defined in NFPA 70.

Type 10 Enclosures constructed to meet the requirements of the Mine Safety and

    Health Administration, 30 CFR, Part 18.

National Electrical Manufacturers Association Approved by NEMA Enclosures Section

    1300 N. 17th Street, Suite 1752 November 2005

    Rosslyn, VA 22209

    NEMA Enclosure Types

    Table B-1

    [From NEMA 250-2003]

    Comparison of Specific Applications of Enclosures

     for Indoor Hazardous Locations

    (If the installation is outdoors and/or additional protection is required by

    Table 1 and Table 2, a combination-type enclosure is required.)

    Provides a Degree of Protection Against Enclosure Types 7 and Enclosure Type 9, Atmospheres Typically Containing8, Class I Groups ** Class II Groups

    (See NFPA 497M for Complete Listing) Class A B C D E F G 10 Acetylene I X ... ... ... ... ... ... ... Hydrogen, manufactured gas I ... X ... ... ... ... ... ... Diethyl ether, ethylene, cyclopropane I ... ... X ... ... ... ... ... Gasoline, hexane, butane, naphtha, propane, I ... ... ... X ... ... ... ... acetone, toluene, isoprene