I've read, searched and scratched and still wonder. I will be wiring an outdoor, 4-wire, 50A SPA this weekend. I have the permit and need to know:
1) Can the EMC conduit (to be installed "on" my house) from my Service Panel to my Spa Disconnect (50A GFCI contained in disconnect panel) act as my ground to the Spa Disconnect? Planning to run 3 - #6 THHN, black, red, white for load and neutral to the disconnect. If not, I presume I will need to add a #10 THHN green for ground.
2) What is the appropriate method (tubing/wire type) to wire the supply side of the disconnect into the side of the tub and around to the other side for connection to the equipment panel?