Installing an electrical supply for a hot tub depends on the voltage requirements. A tub that functions on 120 volts can be plugged into any normal electrical socket, but a 240-volt tub must be connected to its own separate power supply. A hot tub has different electrical requirements depending on whether it is indoors or outdoors.
Hot tubs may need a ground fault circuit interrupter cord for protection, and a breaker must be installed within 5 to 10 feet of the tub in case an emergency shut down is required. The size of the wire is typically determined by the maximum power it draws as well as the distance between the breaker box and the tub. It must also be approved by the National Electric Code. Use copper wire instead of aluminum, and ensure it has THHN insulation.
Place a junction box close to the tub when using wire larger than 10mm squared. All wiring must be placed inside PVC conduit pipes with a rating of at least 90c in order to handle the required heat. Due to the high electrical demands of a hot tub, it must be assigned its own circuit with no other appliances sharing the power.