Breaker Sizing Calculator for Alaska
NEC 2020 breaker sizing math for EV charger installers working in Alaska.
Every EVSE branch in Alaska 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 Alaska
A 40 A continuous EV load requires a breaker rated 50 A (40 × 1.25 = 50.0 A, rounded up to the next standard size). The conductor downstream must carry that 50 A after Alaska's 1.00× ampacity correction.
Code & Utilities
EV installations in Alaska are governed by the 2020 National Electrical Code, in force since 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.
Alaska's primary EV-relevant utilities are Chugach Electric, Matanuska Electric Association, Golden Valley Electric. Each has its own service-upgrade timeline, EV rebate availability, and metering rules — confirm them before quoting commercial work.
Climate & Ampacity
Plan EV feeders against a 75°F ambient in Alaska — the resulting NEC 310.15(B) correction of 1.00× is what trims a #6 THWN-2 down to its true continuous rating. The correction is mild but still NEC-required; document it on the load calc so your inspector sees that 310.15(B) was applied.
Alaska takeaway
Use a 100%-rated breaker only when the panel and breaker are both listed for 100% continuous duty — otherwise the 125% rule applies. Alaska inspectors enforce this rigorously on Article 625 work.