I recently hooked up the wiring to a 240v 3-wire spa and I am concerned about the size of the ground wire on the supply line inside the basement from the main panel box to the outside disconnect. This cable is NM-B-6/3-W/G and is protected by a 50 amp breaker in the panel. The disconnect is 60amp GFCI breaker with 4 COP THHN-6 lines (red, black, white, and green) running in conduit to the spa. The white line is unused and only the 2 hot lines and the ground are hooked up. My concern is the ground wire in the basement is not #6 but is lighter in gauge, maybe #12. Everything seems to be working but is this something that I should be worried about. Is the lighter ground wire carrying a heavy current?
