Motor enclosures weather-protected

Motor enclosures for outdoor use are NEMA weather-protected Type II, totally enclosed, fan-cooled, or drip-proof with weather protection. Motors of the latter type are widely used. Not only are they less expensive than the other types, but they also have a service factor of 1,15. The above enclosure types are all suitable for the Class I, Group D, Division 2 classifications usually encountered. 

FIG. 29-4 Examples of open dripproof, totally enclosed fan-cooled, and weather-protected motor enclosures. Photo courtesy of Reliance Electric Company, Cleveland, Ohio.)... 

Enclosures. In chemical plants and refineries, motors may need to be resistant to the weather or to corrosive and hazardous locations. The kind of housing that must be provided in particular situations is laid out in detail in the National Electrical Code, Article 500. Some of the classes of protection recognized there are in this table of differential costs. 

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