ECN Forum Forums Code Related Discussion NEC & other Code issues ground wire under slab

I need to run 1#4 copper wire from each of 2-200 amp safety switches to the cold water pipe where it enters the building about 90 feet away. The easiest way to do it would be to run them in the trench with the copper plumbing. Should I run bare or THHN or put them in a PVC conduit?
Thanks
bob
I see the thread titled: "Color Code for GEC in a Main Service Panel" that there may be an issue with the color if I use THHN

[This message has been edited by elecbob (edited 03-12-2003).]

Are these safety switches the service disconnects? I'd run it as a bare conductor if it was up to me. This will provide more contact with the earth and create a better grounding electrode. I don't know of a code section that would require it in PVC.
Don

Yes they are the service disconnects. The earth contact seemed good to me too. Thanks for the input.
bob