IEEE 303-2023

This recommended practice is limited to auxiliary devices associated with rotating electrical machines operating in Class I, Division 2 or Zone 2 areas or Class II, Division 2 areas or Zone 22 areas under the practice of NFPA 70, National Electrical Code® (NEC®) and CSA C22.1, Canadian Electric Code (CE Code).6 This recommended practice is not an attempt to rewrite or otherwise supersede applicable sections or clauses of these noted documents or any other codes or ordinances. Rather, it is intended to serve as a supplement to existing codes that in this area may not be sufficiently specific to serve as a guide to good engineering practice.

The following information is intended to bring together a brief description of basic electrical practices with regard to the application and installation of auxiliary devices to rotating electrical machines operating in Class I, Division 2 or Zone 2 or Class II, Division 2 or Zone 22 locations using the NEC and the CE Code. It should be understood that this information is only a recommended practice to promote consistent application of such devices and must be used with sound engineering judgment.

Revision Standard - Active. This recommended practice applies to the application and installation procedures of auxiliary devices in or on electric rotating machines that are employed in hazardous locations classified as Class I, Division 2 and Zone 2 and Class II, Division 2 and Zone 22 under commonly used worldwide regulations. These regulations are: the National Electrical Code® (NEC®); the Canadian Electrical Code (CE Code); and combined practices of the International Electrotechnical Commission (IEC). Included is a list of source documents, definitions and nomenclature. Devices include terminal housings, heaters, surge protection, power factor correction capacitors, shaft bonding (shaft grounding), and enclosures. Special marking requirements are also discussed.