EV Charger Load Calculator for South Dakota
NEC 2020 ev charger load math for EV charger installers working in South Dakota.
Sizing an EV charger circuit in South Dakota starts with NEC 2020 Article 625 — the EVSE branch must be sized to 125% of the continuous load. Hot-climate warm-band states like South Dakota (92°F design ambient) also force a 0.88× ampacity correction at 75°C terminations.
Worked example for South Dakota
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 Dakota'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
EV installations in South Dakota are governed by the 2020 National Electrical Code, in force since 2023. That includes Article 625 (Electric Vehicle Power Transfer System) requirements: 125% continuous-load sizing on EVSE branch circuits, GFCI protection at outdoor receptacles, and provisions for energy management systems on shared circuits.
In South Dakota, you'll most often interconnect with Black Hills Energy, Otter Tail Power, MidAmerican Energy SD. Their make-ready, time-of-use, and demand-charge structures vary widely; pull the specific tariff before sizing service equipment.
Climate & Ampacity
South Dakota's representative summer design ambient is around 92°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 Dakota takeaway
Always cross-check the EVSE manufacturer's listed maximum overcurrent rating; Black Hills Energy may also have specific service-upgrade or load-management requirements you'll need to coordinate before final inspection.