EV Charger Load Calculator for Ohio
NEC 2017 ev charger load math for EV charger installers working in Ohio.
Sizing an EV charger circuit in Ohio starts with NEC 2017 Article 625 — the EVSE branch must be sized to 125% of the continuous load. Hot-climate warm-band states like Ohio (89°F design ambient) also force a 0.88× ampacity correction at 75°C terminations.
Worked example for Ohio
For a 80 A Level 2 charger on a 240 V single-phase circuit, the OCPD is sized to 100 A (80 × 1.25 = 100.0 A, rounded up to the next standard breaker). The conductor must carry 100 A after Ohio's 0.88× correction — that typically lands at #6 AWG copper THWN-2 for a residential garage run, with conduit fill checked separately if you're stacking multiple home runs.
Code & Utilities
Ohio currently enforces the NEC 2017 edition, adopted in 2020. That includes Article 625 EVSE rules and the 125% continuous-load factor on charging branch circuits, though some 2020-cycle changes (like expanded EMS provisions) are not yet enforced statewide.
Ohio's primary EV-relevant utilities are AEP Ohio, Duke Energy Ohio, FirstEnergy, DP&L. Each has its own service-upgrade timeline, EV rebate availability, and metering rules — confirm them before quoting commercial work.
Climate & Ampacity
Ohio's representative summer design ambient is around 89°F, which yields a 0.88× ampacity correction factor at 75°C terminations per NEC 310.15(B)(1). Because the correction is below 0.9, conductors that "look fine" on a 30°C ampacity table will not carry their nameplate current here — always derate explicitly.
Ohio takeaway
Always cross-check the EVSE manufacturer's listed maximum overcurrent rating; AEP Ohio may also have specific service-upgrade or load-management requirements you'll need to coordinate before final inspection.