Bonding question for service

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maintenceman

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Ok so I have a question, stay with me here lol. This question is solely on the bonding of the service for the building. I know the answer I think, but want to hear it from someone else.

1. Building has been added on to twice, so there all one building but added to 2 times.
2. service comes into building now (into the 2nd and most recent addition) to a 800a transfer switch. In transfer switch the nuetral is bonded to cabinet
3. out of TS, is parallel feeds to generator for TS, and (2) parallel feeds to loads. One new panel and one feed to old existing service. New service feed (addition #2) is right next to TS and is fine I think. Old service (original building and addition #1) is about 200' away and is fed with parallel feed, but only has 3 hots and a ground in the pvc's feeding it (no ground)
4. The new service is fine, grounds and nuetrals seperated in panels, etc (Addition #2 to building)
5. Old service that is 200 or so feet away is fed to an MCC where the nuetral, grounds, water ground and ground rod are all bonded together.
6. Then out of MCC it feeds the original building service, which is (2) 200a disc. Each of these disconnects are also bonded inside
7. So in turn, the nuetral is bonded in 4 different places!

So since the newest addition (I did not work here then)we have have had some problems with computers and electronics going bad and quitting randomly. So 2 questions that I think I know the answers to.

1. Is this bonding legal somehow?
2. Could this bonding be causing problems with electronic devices in building?

Thanks for replies and sorry if its confusing the way I have wrote it out
 
Maybe this would help understand it better.
Lets call the 3 services (phases/additions to building) A,B,C. "A" was original service of first phase, "B" the next addition to building/service and "C" is the most recent addition/service. The service used to come into "A" obviously, but now the main service has been moved and comes in the "C" phase. So A,B become subpanels of "C" correct? When the service comes in the building it goes right into a transfer switch and then fed out accordingly. Problem is the nuetral is bonded at "A, B and C" locations. With the water and ground rod at the "B" location where the service used to enter the building at, was never re-located to the new service location "C"
 
Can't say for certain if it is non-compliant as that'll depend a lot on when the different construction phases were approved by AHJ and the Code in effect at the time. It used to be feeders could be run without a grounding conductor, as long as the grounded conductor was bonded on the load end and also had a GES. As I recall, the most recently allowed situation was for feeders to another building or structure, not the same building or structure.

..and the answer to question #2 is yes. Grounding to grounded at several locations could introduce voltage gradients in the thousands of volts on the system during any nearby lightning strikes.
 
maintenceman said:
Ok so I have a question, stay with me here lol. This question is solely on the bonding of the service for the building. I know the answer I think, but want to hear it from someone else.

1. Building has been added on to twice, so there all one building but added to 2 times.
2. service comes into building now (into the 2nd and most recent addition) to a 800a transfer switch. In transfer switch the nuetral is bonded to cabinet
3. out of TS, is parallel feeds to generator for TS, and (2) parallel feeds to loads. One new panel and one feed to old existing service. New service feed (addition #2) is right next to TS and is fine I think. Old service (original building and addition #1) is about 200' away and is fed with parallel feed, but only has 3 hots and a ground in the pvc's feeding it (no ground)
4. The new service is fine, grounds and nuetrals seperated in panels, etc (Addition #2 to building)
5. Old service that is 200 or so feet away is fed to an MCC where the nuetral, grounds, water ground and ground rod are all bonded together.
6. Then out of MCC it feeds the original building service, which is (2) 200a disc. Each of these disconnects are also bonded inside
7. So in turn, the nuetral is bonded in 4 different places!

So since the newest addition (I did not work here then)we have have had some problems with computers and electronics going bad and quitting randomly. So 2 questions that I think I know the answers to.

1. Is this bonding legal somehow?
2. Could this bonding be causing problems with electronic devices in building?

Thanks for replies and sorry if its confusing the way I have wrote it out
Click to expand...

Ok, I gather from your post the following and my answers are based on this: This is one building, not multiple buildings, there is one service, the transfer switch is your sole service disconnect and is service rated.....Yes?

Your grounding electrodes need to go to the transfer switch, not to any "sub panel" (technically they could land anywhere on the service neutral). Neutrals and grounds need to be isolated everywhere except the transfer switch (unless you have some old range or dryer circuits) , which needs a MBJ and neutrals and grounds bonded . Every "sub panel" needs an EGC, whether it be a wire or approved raceway. Any Questions?
 
Correct on all. What I have come to find out is that the transfer switch used to sit outside the building before the last addition. When they added the last addition, it put the transfer switch inside the building now. Transfer switch I guess has been service disconnect all along for building, which may have an exception to let the bonding be inside building and not at transfer switch?? Problem I think is when they added another service off transfer switch for newest addition, that exception is no good anymore. Bonding then needs to occur in transfer switch, not 200' feet away
 
ORIGINALLY_________________________200'NO GROUND WIRE
UTYTRANS------------------TRANS SW-------------------------------------BUILDING SERV PART1 AND 2=WATER GR/ROD HERE
_____________________________________________________________-- NUET BONDED HERE



**NOW____________________________200' NO GROUND WIRE
UTYTRANS------------------TRANS SW-------------------------------------BUILDING SERV PART 1 AND 2=WATER GR/ROD HERE
________________NUET BONDED HERE TO CABINET_________________NUET BONDED HERE
__________________________|
_ ________________________|
__________________________|-------NEW ADDITION SERVICE ADDED LAST YR FROM TRANS SW
_________________________________ NO BONDING HERE
 
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