EV Charger Load Calculator for Utah
NEC 2023 ev charger load math for EV charger installers working in Utah.
Sizing an EV charger circuit in Utah starts with NEC 2023 Article 625 — the EVSE branch must be sized to 125% of the continuous load. Hot-climate hot-band states like Utah (99°F design ambient) also force a 0.82× ampacity correction at 75°C terminations.
Worked example for Utah
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 Utah's 0.82× 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
Utah currently enforces the NEC 2023 edition, adopted in 2024. That includes Article 625 (Electric Vehicle Power Transfer System) requirements: 125% continuous-load sizing on EVSE branch circuits, GFCI protection at outdoor receptacles, and provisions for energy management systems on shared circuits.
Utah's primary EV-relevant utilities are Rocky Mountain Power, Murray City Power, Logan Light & Power. Their make-ready, time-of-use, and demand-charge structures vary widely; pull the specific tariff before sizing service equipment.
Climate & Ampacity
Utah's representative summer design ambient is around 99°F, which yields a 0.82× 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.
Utah takeaway
Always cross-check the EVSE manufacturer's listed maximum overcurrent rating; Rocky Mountain Power may also have specific service-upgrade or load-management requirements you'll need to coordinate before final inspection.