How to Wire 120-Volt Hot Tubs

Wiring a 120-volt hot tub usually means installing a Ground Fault Circuit Interrupter (GFCI) receptacle. Most 120-volt hot tubs are cord-and-plug-connected appliances. The National Electric Code and local electrical codes require that hot tubs be plugged into a GFCI-protected receptacle. Ground fault circuit interrupters protect people against a ground fault condition which can cause fatal electric shocks. A ground fault occurs when the circuit's neutral wire, the grounded conductor, comes into contact with a conducting surface. Standard circuit breakers and fuses protect against short circuits but not against ground faults.

• 1

  Turn off the branch circuit breaker to the receptacle to be replaced with the GFCI receptacle. Turn on the non-contact voltage tester bringing the tester's probe near the receptacle. If there is still voltage present, the tester will beep loudly. In some cases, there may be more than one circuit in a receptacle box. When there is more than one circuit, you will have to turn off more than one circuit breaker before working on the circuit.

• 2

  Remove the receptacle cover plate screw. Remove the two 6-32 screws securing the receptacle to the box. Pull the receptacle out of the box. Check the number of black and white wires entering the box and connecting to the receptacle. If the receptacle has one white wire and one black wire connected to it, skip the next step. If the receptacle has two white wires and two black wires connected to it, go to the next step.

• 3

  Disconnect all the wires from the receptacle. Separate the white and black wires. Turn on the circuit breaker and use the non-contact voltage tester to determine which black wire has voltage on it. Memorize the position of that wire. Turn off the circuit breaker.

• 4

  Cut off the stripped ends of the wires with the wire cutters. Remove 3/4 of an inch of insulation from the ends of the insulated wires with the wire strippers. Make loops in the stripped ends with the needle-nose pliers. Make the opening in the loop large enough to slip around a terminal screw.

• 5

  Connect the black wire bringing the power from the breaker and its associated white wire to the terminals marked "Line" on the GFCI receptacle. Attach the black wire to the brass screw, and the white wire to the silver screw. Place the loops around the screws in a clockwise direction and tighten the screws down on the wire.

• 6

  Connect the second set of black and white wires, if there is a second set, leaving the box continuing on to the next receptacle to the terminal screws marked "Load." Connect the black wire to the brass screw and the white wire to the silver screw.

• 7

  Connect the bare copper ground wire to the green terminal screw. Secure the GFCI receptacle in the box with the 6-32 screws and install the new cover plate that came with the GFCI receptacle

• 8

  Turn on the circuit breaker. Test the GFCI function by pressing the "TEST" button on the face of the receptacle. The "RESET" button should pop out. Press the "RESET" button to reset the receptacle. Plug in the hot tub.