I am curious as what you guys would do. This building has four seperate services and three seperate water services. How whould you go about bonding the services to the water services. Would you just go to the nearest water service? The problem is water lines form other water services end up in the area served by for instance Service A. I never really ran into this before. Any help would be great! Thanks in advance.......Brian

Brian,
Personally, I would bond all of the Services,
together and Earth (Ground) them all, using as larger wire as possible, this makes sure that all of the Services are at the same potential(Ground).
Hope this is of some help to you.

Brian,

Sounds like a structure with a lot of history. I'm guessing there are fire walls between the units? To the extent that fire walls seperate the units, treat those areas as seperate buildings. As in a seperate building, run the GEC to the water service entrance that is the main supply for that unit. When two water services supply one unit, 250.50 says they must be bonded together as part of the Grounding Electrode System.

Al

in terms of 'objectionable current', and such matters that drive the datacom guys nuts, i sense a difference in the 4 services being in proximity to each other vs. being on opposite ends of the structure served.

The building is one big industrial plant. The services are all in seperate areas of the plant as are the water mains. I am thinking of bonding all the water services together and then bonding the services to the closest water main. I think this will be alot safer than what they have now. If any one has any ohter suggestions they would be appreciated.............Brian

Article requires that “each item in 250.52(A)(1) through (A)(6) shall be bonded together to form the grounding electrode system”. So all the water services would have to be bonded together and connected to each service. Again assuming that they are in one building and there are no firewalls.