NEMA - ANSI/NEMA MG 1
Motors and Generators
|Publication Date:||1 January 2006|
This Standard applies to the classification of degrees of protection provided by enclosures for rotating electrical machines. It defines the requirements for protective enclosures that are in all other respects suitable for their intended use and which, from the point of view of materials and workmanship, ensure that the properties dealt with in this standard are maintained under normal conditions of use.
This standard does not specify:
• degrees of protection against mechanical damage of the machine, or conditions such as moisture (produced for example by condensation), corrosive vapours, fungus or vermin;
• types of protection of machines for use in an explosive atmosphere;
• the requirements for barriers external to the enclosure which have to be provided solely for the safety of personnel.
In certain applications (such as agricultural or domestic appliances), more extensive precautions against accidental or deliberate contact may be specified.
This standard gives definitions for standard degrees of protection provided by enclosures applicable to rotating electrical machines as regards the:
protection of persons against contacts with or approach to live parts and against contact with moving parts (other than smooth rotating shafts and the like) inside the enclosure and protection of the machine against ingress of solid foreign objects;
protection of machines against the harmful effects due to ingress of water.
It gives designations for these protective degrees and tests to be performed to check that the machines meet the requirements of this standard.