Voltage Drop Calculator for Utah
NEC 2023 voltage drop math for EV charger installers working in Utah.
Utah EV installs frequently push past 100 ft of conductor — detached garages, parking-lot DCFC pedestals, and multifamily carport runs all add distance. NEC 2023 recommends a 3% branch / 5% total voltage-drop ceiling.
Worked example for Utah
A 40 A Level 2 charger at 120 ft on 240 V single-phase #6 Cu shows roughly 2.0% drop. That's below the 3% NEC recommendation, so you'd stay at #6. Utah's 0.82× ampacity correction is independent of voltage drop but applies on the same conductor pick.
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
Voltage drop is a recommendation, not a hard NEC rule — but EVSEs throttle aggressively below ~228 V on a 240 V circuit, so customers in Utah will notice any drop above 5%.