Grounding Conductor Calculator for Alaska
NEC 2020 grounding conductor math for EV charger installers working in Alaska.
EGC sizing in Alaska follows NEC 2020 Table 250.122, indexed off the upstream OCPD rating, with parallel rules for parallel sets and increased-conductor adjustments under 250.122(B).
Worked example for Alaska
For a 200 A EVSE branch, Table 250.122 calls for a minimum #6 Cu equipment grounding conductor. If you upsize the phase conductors for voltage drop in Alaska's long runs, NEC 250.122(B) requires the EGC to be upsized proportionally.
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
On DCFC sites with parallel feeder sets, each parallel raceway needs its own full-size EGC — a detail inspectors in Alaska catch frequently on commercial submittals.