Voltage Drop Calculator for Delaware
NEC 2020 voltage drop math for EV charger installers working in Delaware.
Delaware EV installs frequently push past 100 ft of conductor — detached garages, parking-lot DCFC pedestals, and multifamily carport runs all add distance. NEC 2020 recommends a 3% branch / 5% total voltage-drop ceiling.
Worked example for Delaware
A 40 A Level 2 charger at 180 ft on 240 V single-phase #6 Cu shows roughly 2.9% drop. That's below the 3% NEC recommendation, so you'd stay at #6. Delaware's 0.88× ampacity correction is independent of voltage drop but applies on the same conductor pick.
Code & Utilities
The applicable code in Delaware is the NEC 2020, which the state 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.
Delaware's primary EV-relevant utilities are Delmarva Power, Delaware Electric Cooperative, Delaware Municipal 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 91°F ambient in Delaware — 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.
Delaware takeaway
Voltage drop is a recommendation, not a hard NEC rule — but EVSEs throttle aggressively below ~228 V on a 240 V circuit, so customers in Delaware will notice any drop above 5%.