Article 680, Part VI of the National Electrical Code (NEC) provides the requirements for permanently installed therapeutic pools and tubs. Here are some highlights from this area of the Code:
- The outlet supplying a self-contained therapeutic tub or tank must be GFCI-protected, unless otherwise noted in Art. 680 [Sec. 680.62(A)(1)].
- Something that is “otherwise noted” in Part VI: The tub or tank is three phase or rated over 250V or has a heater load of more than 50A.
- Part VI enumerates five types of parts that must be bonded [Sec. 680.62(B)]. One way to avoid an inadvertent omission is to follow this rule: If it's metallic and non-current carrying, bond it. That way, everything is at the same potential and you have overlooked nothing. The additional cost of accidentally “overbonding” is negligable.
- There is an exception to the Part VI bonding requirement, and also to the “bond everything” approach. Don't worry about small conductive surfaces unlikely to become energized, such as drain fittings not connected to metal pipes.
- Part VI also provides “grounding” requirements [Sec. 680.62(D)]. These are all about connecting to the equipment grounding conductor, not connecting to earth [Art. 100].