501.10(B)(1) Wiring Methods. Class I, Division 2.

This area directly adjacent to this fuel dispenser is a Class I Division 2 location. RMC or IMC with listed threadless fittings could be used here and would be code compliant.
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This area directly adjacent to this fuel dispenser is a Class I Division 2 location. RMC or IMC with listed threadless fittings could be used here and would be code compliant.

Code Change Summary: Changes were made to the allowable wiring methods used in a Class I Division 2 location.

Article 501 is all about Class I hazardous locations. The Class represents the type of flammable material, whereas the Division represents the conditions where the flammable materials are used or stored and the likelihood of the flammable material being present.

Examples of Class I locations include fuel dispensing, spray booths where volatile flammable solvents are used, gas generator rooms and other portions of gas manufacturing plants where flammable gas may escape.

Section 501.10(A) specifies all of the types of wiring methods permitted to be used in a Class I Division 1 hazardous location. Those methods are also permitted to be used in a Class I Division 2 location which is less restrictive than a Division 1 location. Two of the allowable wiring methods for a Class I Division 1 location are threaded rigid metal conduit (RMC) and threaded steel intermediate metal conduit (IMC).

In the 2017 NEC, revisions were made to 501.10(B), pertaining to Class I Division 2 locations, to allow RMC and IMC with listed threadless fittings. Requiring only threaded fittings as in 501.10(A) was too restrictive since many cable types permitted in Class I Division 2 locations were only required to use listed fittings. Many listed cable fittings are threadless and permitted in Class I Division 2 locations.

Another change was the addition of Cablebus to the permitted wiring methods in a Class I Division 2 location. Cablebus is similar to cable tray with spacers between the conductors. Since tray cable is allowed in a Class I, Division 2 location, there is no reason a cablebus with insulated cables shouldnt also be allowed.

Below is a preview of the NEC. See the actual NEC text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2017 NEC edition of NFPA 70.

2014 Code Language:

501.10(B) Class I, Division 2.

(1) General. In Class I, Division 2 locations, the following wiring methods shall be permitted:

(1) All wiring methods permitted in 501.10(A).

(2) Enclosed gasketed busways and enclosed gasketed wireways.

(3) Type PLTC and Type PLTC-ER cable (see NEC text for remainder).

(4) Type ITC and Type ITC-ER cable as permitted in 727.4 and terminated with listed fittings.

(5) Type MC, MV, TC, or TC-ER cable (see NEC text for remainder).

(6) In industrial establishments with restricted public access (see NEC text for remainder).

(7) Optical fiber cable Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC (see NEC text for remainder).

2017 Code Language:

501.10(B) Class I, Division 2.

(1) General. In Class I, Division 2 locations, all wiring methods permitted in 501.10(A) and the following wiring methods shall be permitted:

(1) Rigid metal conduit (RMC) and intermediate metal conduit (IMC) with listed threadless fittings.

(2) Enclosed gasketed busways and enclosed gasketed wireways.

(3) Type PLTC and Type PLTC-ER cable in accordance with the provisions of Article 725, including installation in cable tray systems. The cable shall be terminated with listed fittings.

(4) Type ITC and Type ITC-ER cable as permitted in 727.4 and terminated with listed fittings.

(5) Type MC, MV, TC, or TC-ER cable, including installation in cable tray systems. The cable shall be terminated with listed fittings.

(6) In industrial establishments with restricted public access (see NEC text for remainder).

(7) Optical fiber cable Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC (see NEC text for remainder).

(8) Cablebus.

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501.10(B)(1) Wiring Methods. Class I, Division 2.

Below is a Real Question from our Electrical Continuing Education Courses for Electrical License Renewal:

Which of the following is permitted to be used in a Class I Division 2 location?

A: RMC with listed threadless fittings.
B: Electrical metallic tubing.
C: Nonmetallic sheathed cable.
D: Flat conductor cable.
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