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

Atmospheres Typically Containing

Enclosure Types 7 and

8, Class I Groups **

Enclosure Type 9,

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,

acetone, toluene, isoprene

I ... ... ... X ... ... ... ...

Metal dust II ... ... ... ... X ... ... ...

Carbon black, coal dust, coke dust II ... ... ... ... ... X ... ...

Flour, starch, grain dust II ... ... ... ... ... ... X ...

Fibers, flyings * III ... ... ... ... ... ... X ...

Methane with or without coal dust MSHA ... ... ... ... ... ... ... X

* For Class III type ignitable fibers or combustible flyings see the National Electrical Code, Article 500.

** Due to the characteristics of the gas, vapor, or dust, a product suitable for one Class or Group may not be suitable

for another Class or Group unless marked on the product.

National Electrical Manufacturers Association Approved by NEMA Enclosures Section

1300 N. 17

Street, Suite 1752 November 2005

Rosslyn, VA 22209