National Electrical Installation Standards

Standards as High as Your Own

Friday, December 15, 2023


Hello Code friends, we are wiring a diesel fuel pump at a private business to serve the company’s truck fleet. Looking at the installation spec’s I am not seeing any classified hazardous locations. There are no other pumps gasoline, diesel, or otherwise, being installed. Does this mean that normal Chapter 3 wiring methods can be utilized? It does not seem correct to me. Thanks, Ralph M.


Hi Ralph, thanks for your question. Generally, diesel fuel dispensing areas not considered classified locations.

Section 514.3(A) provides guidance on when a motor fuel dispensing area is considered an “Unclassified Location”. In areas where flammable liquids with a flash point below 38ºC (100ºF) are not handled, the area shall not be considered classified.

Conventional diesel fuel has a flash point greater than 38ºC (100ºF), as such it would not meet the criteria requiring a classified area per Section 514.3(C). The AHJ may request documentation on the type of diesel fuel being used to confirm the flash point and verify compliance. Also see the NEC® definition in Article 100 of Volatile Flammable Liquid. Hope this helps.

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