NEMA Enclosure Types

NEMA Enclosure Types
National Electrical Manufacturers Association Approved by NEMA Enclosures Section
1300 N. 17
th
Street, Suite 1752 November 2005
Rosslyn, VA 22209
Comparison Between NEMA Enclosure Type Numbers and IEC
Enclosure Classification Designations
IEC Publication 60529 Classification of Degrees of Protection Provided by Enclosures
provides a system for specifying the enclosures of electrical equipment on the basis of the
degree of protection provided by the enclosure. IEC 60529 does not specify degrees of
protection against mechanical damage of equipment, risk of explosions, or conditions
such as moisture (produced for example by condensation), corrosive vapors, fungus, or
vermin. The NEMA Standard for Enclosures for Electrical Equipment does test for
environmental conditions such as corrosion, rust, icing, oil, and coolants. For this reason,
and because the test and evaluations for other characteristics are not identical, the IEC
Enclosure Classification Designations cannot be exactly equated with the enclosure Type
numbers in this Standard.
The IEC designation consists of the letters IP followed by two numerals. The first
characteristic numeral indicates the degree of protection provided by the enclosure with
respect to persons and solid foreign objects entering the enclosure. The second
characteristic numeral indicates the degree of protection provided by the enclosure with
respect to the harmful ingress of water.
Table A-1 provides an equivalent conversion from the enclosure Type numbers in this
Standard to the IEC Enclosure Classification Designations. The enclosure type numbers
meet or exceed the test requirements for the associated IEC Classification; for this reason
Table A-1 cannot be used to convert from IEC Classifications to enclosure Type numbers.