NEC paves the way for safe consumer interface with electric vehicle supply equipment
NFPA Journal®, January/February 2012
For years, the automotive industry has tantalized the American public with the promise of a viable electric vehicle (EV). From the Baker Model V Electric Victoria, introduced in 1899, to later EVs such as the Citicar EV, the GM Impact, and the GM EV1, carmakers have dabbled with alternatives to the internal combustion engine.
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However, technological and political barriers, coupled with consumer allegiance to fossil-fuel-powered vehicles, have all played a part in delaying EVs from becoming a real option for reliable travel.
Until now. Suddenly, it seems as if many of those obstacles have been overcome, and EVs have become a viable consumer choice, making their way into commercial fleets as well. As more EVs hit the road, NFPA is there to greet them with codes designed to ensure their safe operation.
In the 1990s, as federal clean air legislation pushed for a solution to fossil-fuel emissions, it looked as though the EV would finally achieve its long-sought breakthrough. A flurry of electric vehicle activity on the part of several automobile manufacturers necessitated the creation of a new article for NFPA 70®, National Electrical Code®. Recognizing the need for requirements covering the safe interface between electrically powered vehicles and charging equipment powered by the premises wiring system, the Society of Automotive Engineers (SAE) sponsored a proposal containing a draft of the new NEC article on EVs. This proposal, modified by code-making panel actions, became the new Article 625, which was introduced in the 1996 edition of the NEC. It seemed that everything was in place for EVs to make their way onto American highways.
But the introduction of all-electric vehicles in the late 1990s was a flop with consumers. Carmakers regrouped and introduced hybrid vehicles, which combined electric and internal-combustion technologies and were able to achieve many of the energy-saving objectives of EVs.
With the recent escalation in oil prices, though, came renewed interest in all-electric vehicles. Once again, the NEC was ready. During the 2011 NEC revision cycle, a renewed focus was placed on Article 625, which was revised to accommodate the new EV technology, including new terminology and provisions for using the EV as a power source for the premises wiring system.
The number of EVs available to consumers has exploded over the past couple of years, and many electrical equipment manufacturers have introduced electric vehicle supply equipment. Prudent code creation in the 1996 Article 625 established product listing/certification requirements for this supply equipment, ensuring safe user interface. Public and private initiatives are building EV charging stations around the country at a breakneck pace. These stations provide facilities that, at a minimum, will accommodate ac Level 1 and Level 2 vehicle charging, and at some locations, dc Level 2 (“quick charge”) equipment is available.
NFPA’s Standards Council recently issued two Tentative Interim Amendments to Article 625 in the 2011 NEC. You can view these TIAs, which address the certification of charging equipment and the electrical load associated with charging equipment, at nfpa.org. Issuance of these TIAs exemplifies NFPA’s commitment to making sure the NEC keeps pace with the EV revolution and, most importantly, that the consumer interface is free from electrical hazards — the mission of the NEC.
Jeffrey Sargent is a regional electrical code specialist for NFPA.