Ground Wire Size For 50a Spa

[Atsottles]

Running 6 awg thwn wire from my 50a spa pack gfci to the hot tub. Does the ground wire also need to be 6 awg? Or can I use a smaller wire for the ground?

 

[wwhitney]

Running 6 awg thwn wire from my 50a spa pack gfci to the hot tub. Does the ground wire also need to be 6 awg? Or can I use a smaller wire for the ground?

What the NEC says (copper assumed throughout):

If you are using a 60C limited wiring method, like LFNC in a wet location (common for a spa), then your #6 AWG is the smallest allowed for your 50A circuit. Then the minimum size EGC is #10.

If you aren't limited to a 60C ampacity, then you have upsized your wire from the minimum #8 for 50A. Therefore you have to upsize your EGC proportionately, which means a #8 EGC.

However your spa manual may have more specific requirements, and you have to follow them. It may call out a #6 EGC, perhaps for no good reason, but then you have to use a #6 EGC.

Cheers, Wayne