Wire Size for 346.67 Amps

Typical copper and aluminum wire gauges for 346.67 amps across common run lengths on a 120V circuit, sized to keep voltage drop under 3% and respect the NEC 240.4(D) small-conductor rule. Actual install sizing depends on conductor material, insulation/termination temperature rating, cable type, ambient and bundling derates, and local code.

346.67A Wire Gauge by Distance

DistanceCopper GaugeAluminum GaugeV-Drop (Cu)NEC Status
25 ft 500 kcmil 750 kcmil 0.4472V (0.3727%) check_circle OK
50 ft 500 kcmil 750 kcmil 0.8944V (0.7453%) check_circle OK
75 ft 500 kcmil 750 kcmil 1.34V (1.12%) check_circle OK
100 ft 500 kcmil 750 kcmil 1.79V (1.49%) check_circle OK
125 ft 500 kcmil 750 kcmil 2.24V (1.86%) check_circle OK
150 ft 500 kcmil 750 kcmil 2.68V (2.24%) check_circle OK
175 ft 500 kcmil 750 kcmil 3.13V (2.61%) check_circle OK
200 ft 500 kcmil no aluminum pick 3.58V (2.98%) check_circle OK
250 ft 750 kcmil no aluminum pick 2.96V (2.47%) check_circle OK
300 ft 750 kcmil no aluminum pick 3.56V (2.96%) check_circle OK
400 ftExceeds available gauges
500 ftExceeds available gauges

Aluminum is not typical for 10 AWG and smaller branch-circuit conductors in residential settings. Copper gauges use the NEC 240.4(D) branch-circuit cap, not raw 75°C ampacity.

Other Amperages

This calculator provides estimates for reference purposes only. Always consult a licensed electrician and verify compliance with the National Electrical Code (NEC) and local electrical codes before performing any electrical work.