(a) Electrical installations in hazardous locations, where necessary for operational purposes, must be located in the least hazardous location practicable.

(b) Electrical installations in hazardous locations must comply with paragraphs (b)(1), (2), or (3) of this section.

(1) NFPA 70 Articles 500 through 504 (incorporated by reference, see §110.10-1 of this chapter). Equipment required to be identified for Class I locations must meet the provisions of Sections 500.7 and 500.8 of NFPA 70 and must be tested and listed by an independent laboratory to any of the following standards:

(i) ANSI/UL 674 (2013), ANSI/UL 823, ANSI/UL 844 (2012), ANSI/UL 913, ANSI/UL 1203, UL 1604 (replaced by ANSI/ISA 12.12.01) or ANSI/UL 2225 (2011) (incorporated by reference, see §110.10-1 of this chapter).

(ii) FM Approvals Class Number 3600, Class Number 3610, Class Number 3611, Class Number 3615, or Class Number 3620 (incorporated by reference, see §110.10-1 of this chapter).

(iii) CSA C22.2 Nos. 0-M91, 30-M1986, 157-92, or 213-M1987 (incorporated by reference, see §110.10-1 of this chapter).

Note to §111.108-3(b)(1): See Article 501.5 of NFPA 70 (incorporated by reference, see §110.10-1 of this chapter) for use of Zone equipment in Division designated spaces.

(2) NFPA 70 Article 505 (incorporated by reference, see §110.10-1 of this chapter). Equipment required to be identified for Class I locations must meet the provisions of Sections 505.7 and 505.9 of NFPA 70 and must be tested and listed by an independent laboratory to one or more of the types of protection in ANSI/ISA Series of standards incorporated in NFPA 70.

Note to paragraph (b)(2). See Article 505.9(c)(1) of the NFPA 70 (incorporated by reference, see §110.10-1 of this chapter) for use of Division equipment in Zone designated spaces.

(3) Clause 6 of IEC 61892-7:2007 (incorporated by reference, see §110.10-1 of this chapter) for all U.S. and foreign floating OCS facilities and vessels on the U.S. OCS or on the waters adjacent thereto; chapter 6 of 2009 IMO MODU Code (incorporated by reference, see §110.10-1) for all U.S. and foreign MODUs; or clause 6 of IEC 60092-502 (incorporated by reference, see §110.10-1) for U.S. tank vessels that carry flammable and combustible cargoes. Electrical apparatus in hazardous locations must be tested to IEC 60079-1:2007, IEC 60079-2:2007, IEC 60079-5:2007, IEC 60079-6:2007, IEC 60079-7:2006, IEC 60079-11:2011, IEC 60079-13:2010, IEC 60079-15:2010, IEC 60079-18:2009 or IEC 60079-25:2010 (incorporated by reference, see §110.10-1) and certified by an independent laboratory under the IECEx System.

(c) System components that are listed or certified under paragraph (b)(1), (2), or (3) of this section must not be combined in a manner that would compromise system integrity or safety.

(d) As an alternative to paragraph (b)(1) of this section, electrical equipment that complies with the provisions of NFPA 496 (2013) (incorporated by reference, see §110.10-1 of this chapter) is acceptable for installation in Class I, Divisions 1 and 2. When equipment meeting this standard is used, it does not need to be identified and marked by an independent laboratory. The Commanding Officer, MSC, will evaluate equipment complying with this standard during plan review.

Note to paragraph (d). The Commanding Officer, MSC, will generally consider it acceptable if a manufacturer's certification of compliance is indicated on a material list or plan.

(e) Equipment listed or certified to ANSI/ISA 60079-18 (2012) or IEC 60079-18:2009, respectively, (incorporated by reference, see §110.10-1 of this chapter) is not permitted in Class I, Special Division 1, or Zone 0 hazardous locations unless the encapsulating compound of Ex “ma” protected equipment is not exposed to, or has been determined to be compatible with, the liquid or cargo in the storage tank.

(f) Submerged pump motors that do not meet the requirements of §111.105-31(d), installed in tanks carrying flammable or combustible liquids with closed-cup flashpoints not exceeding 60 °C (140 °F), must receive concept approval by the Commandant (CG-ENG) and plan approval by the Commanding Officer, MSC.

(g) Internal combustion engines installed in Class I, Divisions 1 and 2 (Class I and IEC, Zones 1 and 2) must meet the provisions of ASTM F2876-10 (incorporated by reference, see §110.10-1 of this chapter).