Swim spa electrical requirements

Most need a 50 or 60 A breaker on a dedicated circuit: 154 of the 173 models whose makers publish a size. 14 list 40 A and five list 30 A, the smallest being the American Whirlpool RL5, the Endless Pools R200, the Endless Pools R220, the Endless Pools R500 and the Wellis Beach Club Deluxe.

On some models a smaller supply means the spa can't run everything at once, so the controller turns the heater off while the big pumps run. Endless Pools spells it out: on a 60 A supply the heater turns off when the therapy pump starts, and an 80 A supply keeps it on. 25 models list a recommended breaker above their minimum, three of them Endless Pools models at 80 A. If you plan to swim long in cold weather, ask the dealer which size keeps the heater on.

Because their equipment is split across separate supplies. 27 of the 30 dual-temperature models need more than one circuit, since the swim side and the hot tub side each have their own controls; Master Spas' H2X manual gives each side its own 50 A supply. The other eight are SwimEx models, which put the current's drive, the heater and the filter pump on separate breakers in a sub-panel.

Added up, these run from 70 to 180 A. Before you order, have the electrician check that your main panel has room for that load.

Where the National Electrical Code (NFPA 70) is in force, swim spas fall under Article 680, the part that covers pools, spas and hot tubs. Towns adopt an edition and can add their own rules. Broomfield, Colorado's building department, working from the 2023 code, lists these for outdoor spas and hot tubs:

• A disconnect within sight of the spa, easy to reach and at least 5 ft from its inside wall, that cuts every power leg at once (680.13).
• GFCI protection on any receptacle within 20 ft of the inside wall, and on receptacles that feed pump motors (680.21 and 680.22).
• At least one general-purpose receptacle between 6 and 20 ft from the inside wall, and no receptacle closer than 6 ft (680.22).
• Switches at least 5 ft from the inside wall unless a fence or wall separates them (680.22).
• Metal within 5 ft of the inside wall bonded with #8 copper wire (680.26).

The makers add their own conditions. Master Spas' H2X manual asks for a dedicated four-wire 120/240 V supply with a GFCI breaker, on #6 copper for a 50 A circuit, citing NEC 680.42, and says faulty wiring voids the warranty. Endless Pools says removing or bypassing the GFCI voids its warranty and that long runs may need heavier wire than the chart shows.

A licensed electrician, under a permit where your town requires one. The Master Spas and Endless Pools manuals both put the wiring on a licensed electrician working to the code in force where you live. Nothing on this page replaces that: the table tells you what to ask for, and the electrician and the inspector decide what goes in.

The site work around the wiring (the pad, access for service, a trench for the cable) is covered in the guide to swim spa foundation and installation requirements. Sinking the spa changes some of it; see putting a swim spa in the ground. For a hot tub, see hot tub electrical requirements.