220-240V Hot Tubs

In general hot tubs are designed to operate on a hard wired, GFCI protected 220-240V 50-60 AMP circuit. There are exceptions that require as much as 80, 90, or 100 AMP circuits if the hot tub has multiple heaters, pumps, controls, etc. like in the case of a dual temperature swim spa (hyperlink), however, it is not common. It is the responsibility of the spa owner to ensure that electrical connections are made by a qualified electrician in accordance with the National Electrical Code and any local and
state electrical codes in force at the time of installation. Furthermore, it is important to reference your owner’s manual for your specific make and model’s electrical requirements as the information below is very general.

Most North American hot tub equipment has been designed to operate on 60Hz. Alternating current only, 220-240 volts are required. Make sure that power is not applied while performing any electrical installation. A copper bonding lug has been provided on the electrical equipment pack to allow connection to local ground points. The ground wire must be at least 6 AWG copper wire and must be connected securely to a grounded metal structure such as a cold water pipe. The only electrical supply for your spa must include a 50-60 AMP switch or circuit breaker to open all non-grounded supply conductors to comply with section 422-20 of the National Electrical Code. The disconnect must be readily accessible to the spa occupants, but installed at least five feet from the spa. A Ground-Fault Circuit Interrupter (GFCI) must be used to comply with section 680-42 of the National Electrical Code. A ground fault is a current leak from any one of the supply conductors to ground. A GFCI is designed to automatically shut off power to a piece of equipment when a current fault is detected. Power hook-up to the hot tub must be 240 volt 3 wire plus ground (6 AWG copper). Route the cable into the equipment area for final hook-up to terminals inside the control panel. The spa must be hooked up to a “dedicated” 220-240 volt, 50-60 amp breaker and GFCI. The term “dedicated” means the electrical circuit for the spa is not being used for any other electrical items (patio lights, appliances, garage circuits, etc.). If the spa is connected to a non-dedicated circuit, overloading will result in “nuisance tripping” which requires resetting of the breaker switch at the house electrical panel.

Electrical connections made improperly, or the use of wire gauge sizes for incurring
power which are too small, may continually blow fuses in the electrical equipment box,
may damage the internal electrical controls and components, may be unsafe and in any
case will void your warranty.

110-120V Hot tubs

There are also many “plug-n-play” spas that operate on a standard 15-20 amp household circuit. Most of these have a GFCI built into the end of the cord, and plug right into the outlet. It is important to have dedicated line and circuit even with a plug-n-play hot tub due to the constant electrical demand on this circuit. Therefore, it cannot be shared with any other outlets and cannot support any additional load from things like TVs, appliances, etc. because it can overload the circuit and cause nuisance tripping and potential safety hazards.
Once again, it is important to consult a licensed electrician for a qualified assessment.