How to Wire a Hot Tub Circulating Pump
The circulating pump of a hot tub aids in the movement of water through the jets. A 220v pump powers hot tubs because they require much more power than a standard 120v pump can supply. The pump connection must therefore match that of its control unit, which should support a heavy-duty circuit.
The pumps come in a variety of sizes. The more jets a tub has, the bigger the pump required. However, the different sizes of pumps connect in the same way.
Step 1 - Switch Off the Power
Turn off the power supply to your hot tub at the control unit. Working with live electric wires poses the danger of electric shock.
Step 2 - Prepare the Circulating Pump
Take your circulating pump and remove the covering over the terminal box. Also remove the knockout for the power cable. Install the power cable clamp that came with your pump on the exposed area. Replace the power cable on top of the clamp and secure it in place by tightening the clamp screws.
Step 3 - Connect the Wires
The wiring of a circulating pump involves four wires because the pump is a double-circuit (that is, 220v). Locate terminals inside the terminal box. You'll use these to match the wires from the power supply for connection. You need to strip the wires to about 1/2 inch.
Begin with the ground wire, which is either bare or insulated in green. Connect the wire to the green terminal.
Proceed to connect the black wire, which is a hot wire, to the middle terminal, which should be gold or brass in color.
Connect the red wire, also a hot wire, to the right terminal of the same color.
Finally connect the white wire, which is the neutral wire, to the right terminal that should be silver. Ensure that you tighten all four connections with the screwdriver. Replace the terminal box cover and screw it on firmly as well.
Step 4 - Install the Circulating Pump
To install your circulating pump into your tub, fasten it with the provided screws. Connect the inlet and outlet connections to the pump and then connect the circulating pump into the control unit. Open the gate valves to allow water to get into the tub.
If your tub is an old one and you were replacing the pump, you will need to check for any leaks as the water flows in. If the tub does not leak, double check that you have made the connections correctly. Then turn the power back on at the circuit breaker.