Power Calculator Calculator for Wisconsin
NEC 2017 power calculator math for EV charger installers working in Wisconsin.
Converting between kW and amps is the entry point for nearly every Wisconsin EV install spec — manufacturers publish kW, but the panel, breaker, and feeder live in amps.
Worked example for Wisconsin
A 11.5 kW EVSE draws roughly 48 A at 240 V single-phase, or 14 A at 480 V three-phase. Apply the NEC 2017 125% continuous-load multiplier before sizing the OCPD or feeder. We Energies typically meters DCFC sites at the 480 V three-phase service in Wisconsin.
Code & Utilities
The applicable code in Wisconsin 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.
Wisconsin's primary EV-relevant utilities are We Energies, Madison Gas & Electric, Wisconsin Public Service, Xcel Energy Wisconsin. Each has its own service-upgrade timeline, EV rebate availability, and metering rules — confirm them before quoting commercial work.
Climate & Ampacity
In Wisconsin, the 88°F summer ambient drives a 0.88× 75°C ampacity correction. Bake this into every Level 2 and DCFC conductor pick before you commit to a wire size. 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.
Wisconsin 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.