Breaker Sizing Calculator for Vermont
NEC 2020 breaker sizing math for EV charger installers working in Vermont.
Every EVSE branch in Vermont 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 Vermont
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 Vermont's 0.94× ampacity correction.
Code & Utilities
Vermont currently enforces the NEC 2020 edition, adopted in 2022. 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 Vermont, you'll most often interconnect with Green Mountain Power, Vermont Electric Cooperative, Burlington Electric Department. Each has its own service-upgrade timeline, EV rebate availability, and metering rules — confirm them before quoting commercial work.
Climate & Ampacity
In Vermont, the 84°F summer ambient drives a 0.94× 75°C ampacity correction. Bake this into every Level 2 and DCFC conductor pick before you commit to a wire size. The correction is mild but still NEC-required; document it on the load calc so your inspector sees that 310.15(B) was applied.
Vermont takeaway
Use a 100%-rated breaker only when the panel and breaker are both listed for 100% continuous duty — otherwise the 125% rule applies. Vermont inspectors enforce this rigorously on Article 625 work.