Spa

Can I run 240v through my old 120v wires?

I accidentally wired the outlet next to my Spa for 120volts when I built my house. No problem, the Spa could be wired to heat with either one. But it would heat faster with 240v. I know i will need a 50 amp GFI protected circuit if I go to 240v. Will I need to change the wiring too? I’m assuming the existing wires are 12-3 copper, and the distance to the breaker box is 40′. I could probably figure it out for my self if only I could remember ohm’s law from my high school physics class. Thanks in advance.

NO. Let me repeat that-NO! Your 12 ga. wires are limited to 20A. For the 50A that the tub requires, you will need to run #6 wires. Check and see if a neutral is required, for timers, lights, etc. If so you will need a GFCI breaker or disconnect with 3 #6 conductors and a ground. Otherwise you can 2 #6 conductors and a ground. Hope this helps.

IV-OHM (Spa) – Farewell