Breaker Sizing Calculator for Virginia
NEC 2020 breaker sizing math for EV charger installers working in Virginia.
Every EVSE branch in Virginia is treated as a continuous load per NEC 2020 Article 625 — the OCPD must be sized at 125% of the EVSE's listed maximum draw.
Worked example for Virginia
A 60 A continuous EV load requires a breaker rated 75 A (60 × 1.25 = 75.0 A, rounded up to the next standard size). The conductor downstream must carry that 75 A after Virginia's 0.88× ampacity correction.
Code & Utilities
The applicable code in Virginia is the NEC 2020, which the state adopted in 2021. 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 Virginia, you'll most often interconnect with Dominion Energy Virginia, Appalachian Power, Old Dominion Electric Cooperative. Their make-ready, time-of-use, and demand-charge structures vary widely; pull the specific tariff before sizing service equipment.
Climate & Ampacity
Plan EV feeders against a 92°F ambient in Virginia — the resulting NEC 310.15(B) correction of 0.88× is what trims a #6 THWN-2 down to its true continuous rating. 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.
Virginia takeaway
Use a 100%-rated breaker only when the panel and breaker are both listed for 100% continuous duty — otherwise the 125% rule applies. Virginia inspectors enforce this rigorously on Article 625 work.