Main service board and branch elec. rooms on different building - Grounding

[anbm]

If the main electrical room (with main service entrance board and main ground bar) stays in building A and all branch (satellite) electrical rooms stay in building B.

In building B: can we install one main ground bar in selected elec. room and run ground wires to all satellite elec. room ground bar, then from this main ground bar in building B, we run one big ground wire back to building A and bond to main ground bar in building A electrical room - rather than we run several ground wires from each satellite elec. room in building B to building A?

 

[raider1]

How many feeders are you using to supply building B?

Chris

 

[anbm]

three feeders

1- 2000A
1- 1000A
1- 800A

 

[charlie b]

three feeders

I think you have a violation of 225.30. I also think that Chris was thinking along the same lines, and that was the reason for his question.

One possible solution to your problem would be to put one panel/board/gear in Building B, size it to handle all loads in Building B, and run one feeder to that component from Building A.

 

[raider1]

I think you have a violation of 225.30. I also think that Chris was thinking along the same lines, and that was the reason for his question.

One possible solution to your problem would be to put one panel/board/gear in Building B, size it to handle all loads in Building B, and run one feeder to that component from Building A.

Correct, that was the reason for my question.

Chris

 

[Pierre C Belarge]

three feeders

1- 2000A
1- 1000A
1- 800A

I am wondering how large the service is in Bldg A?
I am wondering how large building B is?
I am wondering why 3 different large feeders to BldgB?
Is bldg B so large as to demand multiple feeders?
If so, maybe 225.30(C) can come into play.

 

[anbm]

Building B has three different tenant spaces with each load described above. Utility power come to building A (actually this is a parking garage) and feeds a main swbd also located in parking garage. Why should we put switchboard in buidling B? Since there is more spaces in parking garage as well as it is closer to existing power line.

At first, my thinking is building A and B must tie to same grounding system, that's why question came up. But I reread the code again, looks like each building need to have separate grounding system even building B load is fed out of building A board. And those three feeders can not share same equipment ground wire, I guess.