Breaker Sizing Calculator for Wyoming
NEC 2017 breaker sizing math for EV charger installers working in Wyoming.
Every EVSE branch in Wyoming is treated as a continuous load per NEC 2017 Article 625 — the OCPD must be sized at 125% of the EVSE's listed maximum draw.
Worked example for Wyoming
A 48 A continuous EV load requires a breaker rated 60 A (48 × 1.25 = 60.0 A, rounded up to the next standard size). The conductor downstream must carry that 60 A after Wyoming's 0.88× ampacity correction.
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
Use a 100%-rated breaker only when the panel and breaker are both listed for 100% continuous duty — otherwise the 125% rule applies. Wyoming inspectors enforce this rigorously on Article 625 work.