NEMA classifications

Table 3-7 shows the NEMA classification of motors and their typical applications. These can have greatly different torque characteristics, as illustrated by Figure 3-15. 

NEMA Classification of Electrical Enclosures (adapted from Reference 2, Table 17.4)... 

There are many ways to classify motors. But whichever one might choose, a familiarity with NEMA classifications and standards will at some point be necessary. Thus NEMA standards are as good a basis as any on which to organize a discussion of motors for the plant engineer. 

National Electrical Manufacturers Association (NEMA) Classifications... 

Appendix B-3 National Electrical Manufaaures Association (NEMA) NEMA Classifications 423... 

The force-ventilated type is preferred when a Division 1 classification is necessary. The standard drip-proof enclosure is preferred in Division 2 or in safe locations. For an outdoor installation, serious consideration should be given to using NEMA Type 2 weather-protected enclosures rather than the completely enclosed types. 

NEMA motor classifications from Reference 31 for usual chemical and petrochemical applications are as indicated in Figure 14-3. 

Table 14-1 IB is useful in comparing motor temperature rise versus class of insulation. See section NEMA MG-1, Rev. 1, Part 1, Section 1, p. 15, Classification of Insulation Systems. ...

Energy Efficient (EE) Motor Designs, 628 NEMA Design Classifications, 630 Classification According to Size, 630 Hazard Classifications Fire and Explosion, 631 Electrical Classification for Safety in Plant Layout, 647 Motor Enclosures, 649 ... 

There are a number of electric motor types available. These motors are classified by the National Electrical Manufacturers Association (NEMA). These electric motor classifications are presented in the NEMA standards [7]. 

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. 

One of the first classifications of base materials for printed drcnits (and other electrical components) was completed by the National Electrical Manufacturers Association (NEMA). NEMA s industrial laminating thermosetting products standard documents many of the materials used in printed circuits as well as specifications for some of their properties. Historical NEMA grades are outlined in Table 6.1 and cross-referenced with IPC-4101 in Table 6.2. Some of the commonly used materials have been FR-2, CEM-1, CEM-3, and, of course, FR-4. 

NEMA has published separate standards publications in a number of classifications. A considerable amount of NEMA standardization activity is in cooperation with other organizations engaged in standardization, such as ASTM, Edison Electrical Institute, NFPA, Underwriters Laboratories, IEEE, and other associations, laboratories, or Government bodies. 

Three-phase, squirrel-cage, IHP motors are the most widely used ac induction motors in industry. Classification of performance requirements has results in NEMA standardized designs that... 

Design B motors are the most popular in industry. As the classification general purpose imphes, the NEMA design B motors can be used to drive most loads such as pumps, fans, and conveyors. 

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