Spa grounding w/ rigid conduit

[rosebed]

We have a 240V hot tub. Rigid conduit carries 2 hot , 1 N (all #6) and 1ground (#8) from Main to line side of 50A GCFI disconnect located adjacent to spa. Rigid then carries 4 wires on load side to spa. Final 18" of load run is non-metallic liquidtight. The #8 ground wire is bonded to spa ground lug and to GCFI ground lug on the load side, and to the GCFI ground lug and the Main neutral. The main is bonded to the homes iron water pipes.
I've had one inspector tell me to disconnect the ends of the ground wire at the GCFI ground bar and to bond the ground wires together so that the ground is carried directly back to the Main. His reasons that connecting at the CGFI bar allows a ground loop back to the spa through the rigid conduit.
I argue that the terminal run of NM liquidtight eliminates the ground circuit he is concerned about. Would there be any possibility of the buried rigid seeing a ground current?
On a different point, was it necessary to run the #8 ground wire from the Main to the GCFI panel or could the rigid have provided sufficient ground?

 

[jimwalker]

Re: Spa grounding w/ rigid conduit

with all do respect this sounds like you wired this yourself.Please consult a licensed electrician as water and electric do not mix well.If you are a contractor i am sure you have an electrician you use.

 

[hurk27]

Re: Spa grounding w/ rigid conduit

I don't see the problem with this unless the grounding conductor is uninsulated which it is required to be. I do wonder as to the reason you ran a #8 grounding conductor all the way back to the panel as a #10 per table 250.122 would have been fine. the only place 680 requires a #8 is for the equal potential Performance bonding required in 680.26, and this conductor is not a EGC and does not have to be ran back to the main breaker panel, it will how ever be bonded to equipment that might have a feed with a EGC that runs back to the main panel. Paralleling grounding conductors will not cause any ground loop. as you must have current running in the grounding conductor before this can happen. And in this case you should never have current on the grounding conductor or EGC to a pool. as the only current carrying conductors are the hot's and the neutral. But without seeing it I'm not sure I'm understanding it. Ground loops occure when EGC's and neutrals are bonded at more than one place and have equipment connected between these two points that might also have a cable that also is bonded to both pieces of equipment. this will cause the neutral current to share all paths to source causing current to flow on this common cable that might not be design to carry current and cause a fire. Or in the case of audio or video cable cause unwanted noise in the form of a 60hz hum.