EV Charger Circuits (NEC 625): Sizing a Level 2 Circuit at 125%, GFCI and the Load You Add to the Service

Tsai Electro is an independent learning site. Not affiliated with TDLR, PSI or NFPA. We explain the ideas in our own words and do not reproduce NEC text. Check every rule and table value in your own 2026 NEC, and follow the charger’s installation instructions.

The rules that decide the circuit

• Continuous load. The overcurrent protection and the conductors for EV charging equipment are sized at not less than 125% of the maximum load (NEC 625.41).
• Individual branch circuit. Each charger outlet is generally supplied by an individual branch circuit with no other outlets (NEC 625.40). The NEC has limited exceptions, such as certain multiple-charger installations; check them in your 2026 book.
• GFCI. Receptacles installed for EV charging need GFCI protection for personnel. The application of GFCI requirements to permanently connected EV charging equipment has also been debated through proposed TIA 1892. Check the applicable adopted NEC text, issued amendments and other relevant GFCI provisions before determining whether additional supply-side protection is required. The protection built into listed EV charging equipment does not automatically satisfy a GFCI requirement for the supply circuit.
• Disconnect. EV charging equipment needs a disconnecting means (NEC 625.43). For qualifying cord-and-plug-connected equipment, the attachment plug and receptacle may serve as the disconnect. Check the exact current and voltage limits in your 2026 NEC rather than assuming every plug-in charger qualifies. For permanently connected equipment, the disconnect generally has to be readily accessible and capable of being locked in the open position; if the disconnect is not at the equipment, check the 2026 rules for marking where it is. This equipment disconnect is separate from any emergency shutoff requirement.
• Emergency shutoff. In buildings other than one- and two-family dwellings, the 2026 NEC adds an emergency shutoff for permanently connected EV charging equipment. It goes in a readily accessible location within sight of the equipment, no closer than 20 ft and no farther than 100 ft, and it disconnects all ungrounded conductors at once and removes power from all the EV charging equipment it is required to cover (NEC 625.43). The rule also covers identification, warning markings and how the shutoff is reset, so check the complete 2026 provision before you choose or locate the shutoff.
• Adjustable chargers. Some listed chargers let a qualified installer set a lower maximum current. Where the listing, the manufacturer’s instructions and the NEC permit that adjustment, the branch circuit can be sized from the configured current, and that setting must be field marked on the equipment (NEC 625.42(B)). A charging preference the user can change in an app is not automatically an approved sizing limit.

Common Level 2 sizes

Charger rated current	Minimum circuit at 125%	Breaker	Minimum copper conductor (75 °C ampacity permitted, no adjustment or correction)
16 A	20 A	20 A	12 AWG
24 A	30 A	30 A	10 AWG
32 A	40 A	40 A	8 AWG
40 A	50 A	50 A	8 AWG
48 A	60 A	60 A	6 AWG

The conductor column assumes copper conductors that are permitted to use the 75 °C ampacity column, 75 °C-rated terminations at both ends, and no adjustment or correction factors. These values do not automatically apply to NM cable or other wiring methods with a lower ampacity limit. Check the wiring method, the insulation and the termination ratings before you pick a conductor. High attic temperatures can reduce allowable conductor ampacity, while a long run may need a larger conductor to limit voltage drop. Check both before selecting the wire size; see our conductor ampacity guide. Check each value against the ampacity table in your 2026 NEC (NEC Table 310.16).

Worked example 1: a 48 A wall charger

1. Circuit rating: 48 × 1.25 = 60 A, so a 60 A breaker.
2. Conductor: at least 60 A. Under the stated assumptions, 6 AWG copper is 65 A in the 75 °C column, so 6 AWG copper meets the requirement with 75 °C terminals. Check the wiring method, its ampacity limits and any adjustment or correction factors before you pick the conductor.
3. Check: 60 ÷ 1.25 = 48 A, the charger’s rating.

Worked example 2: what the charger adds to the service

In the 2026 NEC, a charger goes into the load calculation at its nameplate rating when that rating is available; 7,200 VA is used only when no nameplate rating is available (NEC 120.57). In the 2023 standard method, the rule used the larger of 7,200 VA or the nameplate rating, so do not mix up the editions or the methods. Under the 2026 NEC standard dwelling load calculation, use the EV charger’s nameplate load at 100%, without adding the 125% branch-circuit sizing factor. The 125% factor applies to the charger’s branch-circuit conductors and overcurrent protection. Service and feeder conductors and overcurrent protection must still be evaluated under their applicable sizing requirements. Keep the EV load calculation separate from the final equipment and conductor sizing checks. In the optional dwelling method the EV load also goes in at 100% of its nameplate, with no demand factor. Existing dwellings have a separate optional calculation in Article 120 with its own demand factors for the existing load and for new loads such as an EV charger, so look up that table instead of applying the new-dwelling optional method to an existing home. The 2026 NEC moved the load calculation rules from Article 220 to a new Article 120, so find the EV line there before exam day.

1. Nameplate load: for this example, assume the charger’s nameplate input rating is 48 A at 240 V, so 48 A × 240 V = 11,520 VA. On a real job, use the nameplate rating, not a selected charging current.
2. In the 2026 standard dwelling calculation, the charger’s 11,520 VA nameplate load goes in at 100%, with no extra 125% continuous-load multiplier. The existing-dwelling calculation applies its own demand factors instead. This is the charger’s share only, not the dwelling’s total service load; to see whether an existing service can carry it, finish the full dwelling calculation with the other loads.
3. Check: 11,520 ÷ 240 = 48 A, the charger’s rating, not the 60 A breaker.

In the standard method, that 11,520 VA joins the rest of the dwelling load to check whether the service is big enough. For an existing home, also check the existing-dwelling calculation and any permitted load management system, since either can change the result. If the applicable calculation still exceeds the service rating, look at a code-compliant load management system, a permitted alternative calculation method or a service upgrade.

Check yourself

1. A charger is rated 32 A. What breaker do you install? 40 A (32 × 1.25).
2. Can an EV charger share its branch circuit with a garage receptacle? No. A typical EV charger needs an individual branch circuit, so a general-use garage receptacle cannot share it.
3. An EV charger has a nameplate input rating of 48 A at 240 V. What load goes into the 2026 standard dwelling calculation? 11,520 VA (48 × 240), 100% of its nameplate input rating.

FAQ

Sources checked October 2026

• PSI Candidate Information Bulletin, Texas electrician examinations (updated September 15, 2026): https://test-takers.psiexams.com/api/content/bulletin/1682
• NFPA 70, National Electrical Code, 2026 Edition, Articles 120, 310 and 625