Most full-size hot tubs require a 50-amp, 240-volt GFCI-protected circuit. Smaller plug-in models may use a standard 120V/15A outlet.
| Recommended wire | 6/3 with ground, in conduit |
| Breaker | 50A double-pole GFCI |
| Voltage | 240V |
| Typical amperage | 40A |
| Circuit amperage | 50A |
| NEC reference | NEC 680.44 (GFCI), 680.13 (disconnect) |
| Max recommended distance | About 185 feet one-way for 3% drop at 40A |
A GFCI breaker is required by NEC 680.44. The disconnect must be within sight of the hot tub and at least 5 feet away. All wiring must be in conduit for outdoor runs.
6 AWG copper wire on a 50A, 240V GFCI-protected double-pole breaker is standard for most full-size hot tubs. NEC Article 680.44 requires GFCI protection for all spa feeders. A maintenance disconnect must be within sight of the spa (visible and within 50 feet) and at least 5 feet from its inside wall (NEC 680.13).
Yes — NEC Article 680 requires GFCI protection for all 120V and 240V hot tub and spa circuits. This must be a GFCI circuit breaker, not just a GFCI outlet. The GFCI breaker is typically installed in the main panel.
The hot tub disconnect must be at least 5 feet from the spa perimeter and no more than 50 feet away, within line of sight of the hot tub per NEC 680.13. It must be readily accessible. This is required in addition to the circuit breaker in the panel.
Small inflatable or "plug-and-play" hot tubs are designed for 120V, 15A or 20A outlets. They heat slowly and are limited in power. Full-size hot tubs always require a dedicated 240V, GFCI-protected circuit — they cannot run on standard household outlets.