What Size Wire for a 150 Amp Circuit Breaker? (NEC Table 310.16)
Complete Copper vs. Aluminum AWG wire size, continuous load limit (120A max), ground wire gauge, and conduit sizing for 150A circuits (150A residential main service & commercial distribution panels).
Direct NEC Table 310.16 Answer for 150 Amps
Common Applications for a 150A Circuit
150A residential main service & commercial distribution panels. Remember that under the NEC 125% continuous-load rule (NEC 210.19 & 210.20), a standard 150A breaker can only supply up to 120A of continuous load (any load that runs for 3 hours or more without stopping, such as an EV charger or commercial lighting).
When to Upsize for Voltage Drop (Over 100 Feet)
If your one-way wire run exceeds 100 feet at 240V (or 50 feet at 120V), step up one wire gauge from 1/0 AWG to keep total line voltage drop under the NEC 3% branch-circuit recommendation. Use our Voltage Drop Calculator to check your exact footage.