A hot tub on a snowy Wisconsin evening is hard to beat. Getting there safely takes some electrical planning, ideally before the delivery truck is booked.
120 volt or 240 volt
Small plug-and-play tubs run on 120 volts and need a dedicated, GFCI-protected 15 or 20 amp circuit. They heat slowly and often cannot run the heater and jets at full power together, which matters in winter. Most full-size tubs are 240 volt and need a dedicated 50 or 60 amp circuit, as stated on the manufacturer's nameplate.
GFCI protection
Every hot tub circuit must have ground-fault protection. On a 240 volt tub it is usually built into the outdoor spa disconnect panel.
The disconnect
An emergency shutoff must be within sight of the tub and at least five feet from the water. The idea is that anyone can cut the power quickly, but nobody sitting in the tub can reach it.
Wiring method
Outdoors, spa circuits run in conduit with individual insulated conductors, including an insulated ground. Buried conduit has to be at the correct depth. Overhead power lines above the tub are not permitted within set clearances, so check the spot before the pad is poured.
Bonding
Metal within reach of the tub is bonded together so there is no voltage difference between surfaces a wet person might touch at the same time.
Panel capacity
A 50 amp load is significant. On a 100 amp service it may call for a load calculation, and sometimes an electrical panel upgrade.
Permit and inspection
Hot tub wiring requires an electrical permit. Skipping it can cause trouble with the spa warranty and your insurer. Our hot tub electrical installation service includes the permit, and the same crew can add outdoor lighting and exterior outlets around the patio while the trench is open.