Grounding Conductor Calculator for New York
NEC 2017 grounding conductor math for EV charger installers working in New York.
EGC sizing in New York follows NEC 2017 Table 250.122, indexed off the upstream OCPD rating, with parallel rules for parallel sets and increased-conductor adjustments under 250.122(B).
Worked example for New York
For a 40 A EVSE branch, Table 250.122 calls for a minimum #10 Cu equipment grounding conductor. If you upsize the phase conductors for voltage drop in New York's long runs, NEC 250.122(B) requires the EGC to be upsized proportionally.
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
On DCFC sites with parallel feeder sets, each parallel raceway needs its own full-size EGC — a detail inspectors in New York catch frequently on commercial submittals.