GFCI Wiring
The GFCI may have different construction, but the basic methodology is the
same. If the GFCI is used as the local disconnect, be sure to mount it in view from
the equipment compartment of the spa and at least 5 feet from any inside wall of
the hot tub.
A large portion of 240V spas manufactured today require a 50 amp 4-wire
electrical service. Some hot tubs have load requirements of 30A or 40A, and a few
even 60A, which should correspond to the size of the new feed circuit breaker
installed in the house service panel. The Disconnect GFCI panel's amp rating can
be equal to, or larger than the feed breaker in the main panel.
Hot tubs with mixed voltage components (such as 120V ozonator and 240V heater) require 4-wire systems, which means they require an electrical circuit providing (2) hot wires, (1) neutral, and (1) ground wire.
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The two hot legs (black + red) provide 240 volts (120V +120V). One hot leg with the neutral (white) wire provides 120V. The ground wire (green) carries no current except when a short circuit to ground occurs, causing the circuit breaker to trip on overload (not to be confused with the safety function of the GFCI). |
Use a #6 THHN stranded copper wire, and use four individual insulated conductors: (1)
red & (1) black hot, (1) white neutral, and (1) green (insulated) ground wire.
Some 240V spas (and many older ones) use three wire systems with (2) hot
wires and (1) ground wire, without a neutral wire. Both 3-wire and 4-wire spas must be
GFCI protected. A 4-wire hot tub must not be connected to a 3-wire service. Proper
grounding is also essential. In either case, the disconnect panel must be supplied
with a 4-wire service in order for the GFCI to function as required.