Power Calculator Calculator for Utah
NEC 2023 power calculator math for EV charger installers working in Utah.
Converting between kW and amps is the entry point for nearly every Utah EV install spec — manufacturers publish kW, but the panel, breaker, and feeder live in amps.
Worked example for Utah
A 150 kW EVSE draws roughly 625 A at 240 V single-phase, or 180 A at 480 V three-phase. Apply the NEC 2023 125% continuous-load multiplier before sizing the OCPD or feeder. Rocky Mountain Power typically meters DCFC sites at the 480 V three-phase service in Utah.
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
For three-phase math, always confirm the actual nameplate power factor — DCFC equipment is usually 0.95+ but older site-rated equipment can be lower, which changes the apparent power and the conductor pick.