I am installing a spa and will be running a 220v/50A circuit for its use. Before pouring a slab I would like to bury the conduit and stub it up at the appropriate location.

What type of conduit should I use? Is it best to use solid pipe which I would need a tube bender, or can I use PVC or flex?

Also, the existing wire run from the main panel to the junction box near the spa location has 8 gauge wire (black, red and white) but does not contain a ground. Is a ground required for the GFCI breaker I am required to use and if so, what is the best way to get it? Should I install a grounding rod before I pour the slab?

1" conduit will be sufficient for the spa feeder. if you need any other wiring, then go to 1-1/4 ". PVC Sch 40 is easy to work with. You can get pre-made elbows.

Need to check local codes, many location require you change to steel conduit at the point it exits a concrete slab.

Add a spare 1 " conduit for other telephone, data, or other low voltage systems.

A GFI does not need a ground to operate, however, the spa will require a separate equipment ground conductor, and a ground rod will not be allowed, not sufficient.


Best to replace the #8-3 cable with out ground with a #6-3 cable with ground. Many spas/ hot tubs require a #6 - 50 amp feeder. #8 is not sufficient for 50 amps.