The development of electric vehicle charging infrastructure is without a doubt a huge undertaking that will advance incrementally. There are a few concerns the industry is figuring out about managing this growth. In many areas, one big concern is grid capacity. Another is the anxiety surrounding vehicle range between charging. A third is the continuing advancement of EV battery technology and the progress to autonomous EVs. All are tremendous challenges and significant opportunities.

A big question is where to locate EV charging facilities for optimum service and accessibility for the public. Motor fuel dispensing facilities, where vehicles are currently fueled with traditional fossil fuels, seem like the most logical and practical locations for installing public electric vehicle supply equipment (EVSE) and EV chargers. 

This article takes a closer look at important National Electrical Code considerations relative to using motor fuel dispensing facilities for EV charging facilities.

It is important to consider that many of these EV charging facilities will be installed at existing fueling stations or repair garages. This means that hazardous (classified) locations are already determined, and the existing wiring methods and equipment are approved and operational. The NEC effectively addresses wiring and equipment installed within or adjacent to locations that are classified as hazardous because of fuels used at these facilities. Important Code elements are the locations’ classifications. This must be known first to determine suitable and compliant locations for EV charging equipment at these properties.

Code rules

As a quick review, the use and application of the NEC requires a good working knowledge of how the Code shall be applied to these installations and systems. Section 90.3 provides a road map and clear direction, and chapters 1–4 have general application to all installations. Chapters 5–7 modify or amend the general rules in chapters 1–4. 

In this type of Code application, rules for EVSE and EV chargers are specifically covered by Article 625, and requirements for installations of wiring and equipment in motor fuel dispensing facilities are in Chapter 5, and specifically in Article 514.

Two important conditions must be considered: the capacity of the existing electric service or source to power the equipment, and where the EV charging equipment will be located. 

Section 514.3 clearly addresses the extent of the Class I locations (Divisions 1 and 2) by referencing Table 514.3(B)(1) and (2), including those classifications for aboveground fuel storage tanks. Therefore, the area classification is readily determined. 

Hazardous locations

When dealing with any hazardous (classified) location, exercising ingenuity in the system design and installation are essential. It’s always best to locate any electrical equipment or wiring outside the classified area. This reduces the possibilities of the equipment creating an arc that could ignite any explosive atmospheres present during normal operation of the fueling facility.

For EV charging equipment, this means locating the equipment so the cables and cords cannot extend into the predetermined hazardous locations as indicated in tables 514.3(B)(1) and (2). If any of this equipment is located within the hazardous location, it must be suitable for use in such locations as required by Section 514.4. 

Additionally, all wiring to such EVSE and EV chargers is required to be suitable for installation in and above such locations, which is specified in Section 514.7. Underground wiring at motor fuel dispensing facilities must comply with Section 514.8.

Section 514.11 includes rules for providing emergency electrical disconnects and where they must be located for attended and unattended fueling facilities. It’s important to understand that these emergency disconnects apply only to the fueling systems, not the EVSE or charging equipment. 

The purpose of the emergency disconnects is to remove any electrical arc possibilities in the event of a spill or unexpected breach of the fueling system. Basically, remove the arcing component of the fire triangle to prevent fuel vapor explosions during a rupture or leak.

A heightened level of awareness and diligence is necessary when considering installation of EVSE or EV chargers at fueling sites. The equipment selected, wiring and locations all play a critical role in establishing and maintaining safe operations. It’s far more than just capacity for carrying the additional continuous duty loads of this equipment.