Electric vehicle (EV) charging is not new, as Article 625 was introduced to the National Electrical Code with the 1996 edition. The following year, the Toyota Prius became the first mass-produced (hybrid) electric vehicle. More followed, including Tesla, Nissan, and Chevrolet. Until recently, however, the only viable method for charging an electric or hybrid vehicle was via a direct connection to a power supply, either from premises wiring or at a charging station.
For the 2017 Code cycle, both definitions and requirements have been added to Article 625 for the purpose of regulating another type of EV charging: wireless power transfer, or wireless charging. Before we examine the Code requirements, let’s answer a couple of important questions. First, how does wireless charging work? Second, how efficient is this technology?