scope:

This standard provides requirements for the construction and testing of electrical apparatus, or parts of such apparatus, whose circuits are incapable of causing ignition in:

Classes I, II & III, Division 1 hazardous (classified) locations as defined in Article 500 of the National Electrical Code^®, ANSI/NFPA-70 (NEC^®).

This standard is intended to be used in conjunction with FM Approval Standard 3600 which includes the general requirements that apply to all types of classified location protection methods.

Intrinsically Safe Equipment and/or circuits for use in Class I, Division 1, Groups A, B, C and/or D Hazardous (Classified) Locations shall comply with all applicable requirements in ANSI/ISA-60079-11 2009 for Category ''ia'', Group IIC, IIB and/or IIA.

Exception: Marking of the equipment shall meet the requirements contained in Clause 5.

Purpose

This standard serves as the basis for Approval of intrinsically safe apparatus and associated apparatus.