Amps, breaker and wire by voltage
| Voltage | Current | Breaker (continuous) | Copper wire |
|---|---|---|---|
| 120 V | 8.3 A | 15 A | 14 AWG |
| 208 V | 4.8 A | 15 A | 14 AWG |
| 240 V | 4.2 A | 15 A | 14 AWG |
| 480 V 3-phase | 1.20 A | – | – |
Breaker sized at 125% for continuous loads (NEC 210.20). Motors and electronics draw more current than watts ÷ volts because of power factor.
Frequently asked questions
Can a 15 amp circuit handle 1,000 watts?
Yes. A 15 A circuit at 120 V supplies 1,800 W, or 1,440 W for continuous loads, so 1,000 W fits.
How many amps is 1,000 watts at 12 volts?
83 A at 12 V DC, before inverter losses (about 93 A through a 90% efficient inverter).