grounding grid system

[transman2]

How do you figure how much grounding you do to a building if the building is 100x300ft. Would it be correct if the contractor installs 1 ground rod for each corner (4 total ) and tie to the rebar. Install 3 outside of the indoor panel, ground the coldwater pipe coming in the building and the roof structure and all will be tied together. There is no ground ring installed, the contractor believes the rebar would be fine and act as the ring. This seems very minimal to me and I believe there should be much more grounding done with a building this size. If I'm wrong I'm wrong but if I'm right how do I recommend and design how much grounding I need to be sufficent. Need your help.

 

[John Deere Man]

Art,250.52 Is very clear that if there are other electrodes @ the structure they are to be used as part of the grounding electrode system (i.e. If there is underground metal water pipe 10' or more in length, buildings metal frame, etc..

 

[mcclary's electrical]

How do you figure how much grounding you do to a building if the building is 100x300ft. Would it be correct if the contractor installs 1 ground rod for each corner (4 total ) and tie to the rebar. Install 3 outside of the indoor panel, ground the coldwater pipe coming in the building and the roof structure and all will be tied together. There is no ground ring installed, the contractor believes the rebar would be fine and act as the ring. This seems very minimal to me and I believe there should be much more grounding done with a building this size. If I'm wrong I'm wrong but if I'm right how do I recommend and design how much grounding I need to be sufficent. Need your help.

You have more than enough grounding, IMO,,, a CEE should be used when you pour your cement, and you can throw the rods away