Does your EV charger need a disconnect?

Section 625.43 requires a disconnecting means for EV supply equipment rated more than 60 amperes or more than 150 volts to ground, installed in a readily accessible location and capable of being locked in the open position. Both parts of that sentence matter and people usually only remember the first.Volts to ground is the part that gets misread. On a normal residential 120/240-volt service, the 240 volts your charger uses is 120 volts to ground on each leg, because the system is centre-tapped and grounded at the neutral. So a residential charger is 120 volts to ground regardless of the fact that it says 240 on the label. The 150-volt test is aimed at systems that are configured differently, which in practice means certain commercial services, not houses.That leaves the amperage test, and 60 amperes is the equipment rating, not the breaker. A 48-amp charger is rated 48 amps. It sits on a 60-amp breaker because of the continuous-load rule, and that 60 does not push it over the line. An 80-amp unit does, comfortably, and that is the residential case where the answer flips to yes.

The National Electrical Code is a model document. It has no force anywhere until a state, county or city adopts it, and adoption is neither uniform nor prompt. Some jurisdictions are on the current edition. Plenty are one or two cycles behind. A few states leave adoption to individual municipalities, which is how two towns that share a border end up enforcing different books.On top of that, jurisdictions amend. Local amendments are ordinary and they usually exist for a reason: a fire department that wants an exterior means of isolation, a utility with its own service rules, a history of a particular failure locally. An amendment requiring a disconnect for all EV supply equipment regardless of rating is not an inspector being difficult. It is the law where you live.There is also a judgement call inside the code itself. Where a disconnect is required, it must be readily accessible, and what counts as readily accessible is decided by the authority having jurisdiction. A panel in a locked utility room, behind a stored bicycle, or two floors below the charger invites a conversation you would rather have before the work than after.

Article 225, Part II covers buildings and structures supplied by a feeder or a branch circuit from somewhere else. It requires a means to disconnect all ungrounded conductors supplying the structure, located at the structure. That applies whether you ran a feeder to a subpanel or a single branch circuit to a charger, and it applies at any amperage.This catches people out constantly, because they have correctly worked out that a 48-amp charger needs no 625.43 disconnect and concluded there is no disconnect in the job. Then the inspector asks where the disconnect for the garage is. Both readings of the code are right; they are answering different questions.It is also one more reason a subpanel usually beats a single home-run circuit when you are crossing a yard. If you are installing a disconnecting means at the structure regardless, the marginal cost of making it a small panel with spare spaces is modest, and you never trench again.

Call the office that issues electrical permits and ask three things. Which edition of the NEC is currently adopted here. Are there local amendments affecting EV supply equipment. And do you require a disconnecting means for a hardwired 48-amp residential charger. Those three answers settle the whole subject for your address in about four minutes.Your electrician should already know, and in a market where they do EV work weekly they will. Ask anyway if the run is long, if the charger is going outdoors or on a detached structure, or if you have been quoted by someone from the next county over. A disconnect added at rough-in is a small line item. A disconnect added after a failed inspection is a return visit, a re-inspection fee and a delay.If it turns out you need one, it is not an expensive part. A non-fused disconnect rated for the circuit, mounted within sight of the charger, in an enclosure appropriate to where it lives. It is worth having even where it is optional, honestly, because it means anyone who ever has to work on that equipment can isolate it standing next to it.