ECN Forum Forums General Topics of the Trade General Discussion Area ground size

need to know what size groung conductor to use for the main ground to the water pipe for a 1600 amp service with 4 sets of 600 mcm cables to the utility transformer.

With the information given, table 250.122 shows 4/0 if the egc is copper, or 350 if it's al/cu. 250.122 (F) talks about conductors in parallel also. This should get you started.

You use 250.66, not 250.122
I read it as the max required will be 3/0 copper or 250 MCM al.

Thanks, and apologies for the mix-up, 250.122 is for grounding raceway's and equipment. Seen that first part, where it says minimum size egc, and the rest is history.

If under the Chicago code its 18-27-250.66 page 93
copper (300) in a 1 1/4 inch conduit or tubing.