EV Charger Load Calculator for South Carolina
NEC 2017 ev charger load math for EV charger installers working in South Carolina.
Sizing an EV charger circuit in South Carolina starts with NEC 2017 Article 625 — the EVSE branch must be sized to 125% of the continuous load. Hot-climate warm-band states like South Carolina (94°F design ambient) also force a 0.88× ampacity correction at 75°C terminations.
Worked example for South Carolina
For a 80 A Level 2 charger on a 240 V single-phase circuit, the OCPD is sized to 100 A (80 × 1.25 = 100.0 A, rounded up to the next standard breaker). The conductor must carry 100 A after South Carolina's 0.88× correction — that typically lands at #6 AWG copper THWN-2 for a residential garage run, with conduit fill checked separately if you're stacking multiple home runs.
Code & Utilities
The applicable code in South Carolina is the NEC 2017, which the state adopted in 2018. 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 South Carolina include Duke Energy Carolinas SC, Dominion Energy South Carolina, Santee Cooper. Their make-ready, time-of-use, and demand-charge structures vary widely; pull the specific tariff before sizing service equipment.
Climate & Ampacity
South Carolina's representative summer design ambient is around 94°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.
South Carolina takeaway
Always cross-check the EVSE manufacturer's listed maximum overcurrent rating; Duke Energy Carolinas SC may also have specific service-upgrade or load-management requirements you'll need to coordinate before final inspection.