Voltage Drop Calculator for Wyoming
NEC 2017 voltage drop math for EV charger installers working in Wyoming.
Wyoming EV installs frequently push past 100 ft of conductor — detached garages, parking-lot DCFC pedestals, and multifamily carport runs all add distance. NEC 2017 recommends a 3% branch / 5% total voltage-drop ceiling.
Worked example for Wyoming
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. Wyoming's 0.88× ampacity correction is independent of voltage drop but applies on the same conductor pick.
Code & Utilities
The applicable code in Wyoming is the NEC 2017, which the state 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.
Major electric utilities serving Wyoming include Rocky Mountain Power, Black Hills Energy, Wyoming Rural Electric Cooperatives. Always verify the applicable tariff and any utility-specific requirements (CT cabinets, metering enclosures, demand limiters) at design time.
Climate & Ampacity
Wyoming's representative summer design ambient is around 90°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.
Wyoming 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 Wyoming will notice any drop above 5%.