Solar and EV chargers, in brief

An interest area only. Nothing on Jeffrey’s resume says he has installed solar or an EV charger.

Photovoltaic systems are covered in NEC Article 690. The pieces an electrician meets are modules, racking and its grounding, DC conductors, a DC disconnect, an inverter, and an AC connection to the service. Rapid shutdown (690.12 in recent editions) is there so firefighters are not facing a live array on the roof. Utilities have their own interconnection rules. A permit and an inspection are normal, and the utility can refuse to turn the system on if the paperwork is wrong.

EV supply equipment is Article 625. A charger is usually a continuous load, so the branch circuit is sized at 125 percent of the charge current. The 2023 NEC added 220.57, which tells the service calculation to count the EVSE at 7,200 volt-amperes or the nameplate, whichever is larger. Earlier code cycles treated it as a continuous load without that specific section. The adopted cycle decides. A charger also adds a nonlinear load, which is one reason the power-factor page mentions harmonics when capacitor banks and EV equipment share a system.

Both kinds of work fail in the same boring ways: undersized conductors, a bond in the wrong place, no working space, and a label nobody can read. They are not a weekend project on a live service.

Code section numbers, energy-code rules, and utility practices change by edition and by city. The authority having jurisdiction, and the employer’s written program, decide what applies on a given job.