Needed a dedicated 120V 20A Circuit and Outlet. However, we received the wrong user manual and wired the plug (per the old user manual) for a 120V 30A outlet, using 10 g wire... now we find out we only need 20A outlet. Do we need to rewire with 12g wire or can we use the 10g that is already behind the drywall?
The 10 awg (gauge) wire is fine just install a 20 amp breaker and change the receptacle to a 20 amp if needed. Be sure your new receptacle will accept 10 gauge wire. The better receptacles will... don't get a cheapie. Bigger wire is ok but for example 12 awg for a 30 amp branch circuit would be a no no. Any gfci required with the sauna??
" One nice thing about the NEC articles ... you have lots of choices"