How would you ground this?

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a7

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Here is the situation.
New construction building with metal supporting beams. There is electrical room in the basement with main 600A breaker and other electrical stuff. There is a small room with water main and sprinkler system pipe coming in next to the electrical room.
Here is my question. What would be my main ground? Water main pipe or building structure beams?
What is suplementary ground and how to properly bond it? I still have to drive one 8ft grounding rod into the ground in the basement. The only access I have is in the water-sprinkler room. Do I have to bond this grounding rod with water pipe using only one grounding conductor going to main swith gear or do I have to run two separate grounding wires one for ground rod and one for water pipe??
I think I still have to have another grounding conductor connecting the metal beams? no?
I know there are smart guys over here, any help appreciated, Thanks.
 
Re: How would you ground this?

I still have to drive one 8ft grounding rod into the ground in the basement.
Click to expand...
Not if you have 250.52(A) and .52(B). Water Pipe is your primary, Building steel is your supplementary.

Check out this thread on the topic recently, Bob Badger and friends helped my understanding on this a lot. Check out his picture about halfway down.

[ January 09, 2005, 11:48 AM: Message edited by: georgestolz ]
 
Re: How would you ground this?

As part of your Grounding Electrode System, you will be required to install a GEC to the cold water within 5 ft of entrance to the building. You will then need to supplement it with a "Supplemental"- 250.53(D)(2), (not supplementary - 250.54) grounding electrode, such as the structural steel if it is "effectively grounded". If the steel is effectively grounded, the ground rod will not be necessary as per NEC.

What I am seeing for larger projects is quite overkill ( a waste of money and time) in my opinion.
Steel as the supplemental, then two ground rods with 1/0 or larger to the ground rods. I wonder why?

Bonding of other piping systems as per 250.104 is still required if they are located in/on the building.

Pierre
 
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