I have a scenario that I want to run buy you guys. The job is under the '99 code and I believe the building was done under the '93.
There is a main building which has a utility fed main service (480/277V 1600A)
Right next to it is a central plant building (physically about 15ft) that also contains a utility fed main service (480/277V 1600A) from the same utility transformer as the main building. The two buildings are connected by a "utility bridge", for lack of a better term, that was used to conceal mechanical piping that runs from the central plant to the main building. There is an expansion joint at the connection of the bridge to the main building and the cold water for the site enters the central plant, feeds equipment in there and runs overhead through the "utility bridge" to the main building.
The central plant cold water ground is properly connected within 5ft of where the water service enters the central plant. The main buildings cold water ground is connected about 20ft from where the water line enters the main building which is about 100ft away from where the water line emerges from the ground in the central plant. (the UG is metalic) I believe since the buildings are connected it should be treated as one building with two services and the main buildings cold water ground should be connected at the same place the central plant cold water ground is.
There are a couple of things to factor in here though. The building is part of a hospital campus so it could possibly meet the exception of having only qualified personnel service the installation. It also could be considered two separate buildings in which case the main buildings CW ground would just have to move about 15ft to become compliant. The problem with this is the CW entrance to the building is overhead from another building. This would also open a can of worms with the emergency system as all the feeds to the main building from the central plant would need to have service rated disconnects and additional grounding.
I don't really have a specific question, I am just looking for your thoughts on this.
Edited to add picture. It shows how the buildings are connected. (Sorry for the fence thats in the way)
[This message has been edited by Nick (edited 07-30-2004).]