Wire Size Calculator for New York
NEC 2017 wire size math for EV charger installers working in New York.
Wire sizing in New York is governed by NEC 2017 Table 310.16, with the state's 88°F summer ambient driving a 0.88× correction factor at 75°C terminations per Table 310.15(B)(1).
Worked example for New York
A 60 A continuous EV branch needs a conductor whose corrected ampacity meets or exceeds 60 A. In New York's 0.88× correction, that means picking a conductor whose 30°C-rated ampacity is at least 69 A. For copper THWN-2 in EMT, that typically lands at #6 AWG; aluminum requires one to two sizes larger.
Code & Utilities
New York currently enforces the NEC 2017 edition, 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 New York include Con Edison, National Grid, PSEG Long Island, NYSEG, Central Hudson. Their make-ready, time-of-use, and demand-charge structures vary widely; pull the specific tariff before sizing service equipment.
Climate & Ampacity
New York's representative summer design ambient is around 88°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.
New York takeaway
Don't forget conduit-fill derating per NEC 310.15(C)(1) when more than three current-carrying conductors share a raceway — a common condition on multifamily and workplace EVSE home-run racks in New York.