The scope of this Recommended Practice is limited to auxiliary devices associated with motors operating in Division 2 areas, classified as Class I, Groups A, B, C, and D locations. This Recommended Practice is not an attempt to rewrite or otherwise supersede applicable sections of the National Electrical Code (NEC) or any other codes or ordinances. It is intended, rather, to serve as a supplement to existing codes that in this area are not sufficiently specific to serve as a guide to good engineering practice. The guidance contained herein, therefore, is in addition to the NEC requirements for wiring systems for hazardous areas

The following information is intended to bring together a brief description of basic electrical practices in regard to the application and installation of auxiliary devices to motors operating in Class I, Groups A, B, C, and D, Division 2 areas. It shall be understood that this information is only a guide to promote consistent application of such devices but must be used with sound engineering judgment.