Two Bonding Jumpers. Should I get rid of one?

[slushin]

I have a situation where an old switchgear, which used to be the main service for the building, is now downstream from a new switchgear which now serves as the service entry. The new switchgear neutral and ground are bonded as required by NEC. However, the old switchgear still has a bonding jumper which bonds neutral to ground. I have asked the contractor to remove the bonding jumper in the old, downstream switchgear, but he is reluctant as he says the code does not require it.

I've heard that having two bonds can cause ground loops, but is it also a safety issue? Is there anything in the code that forbids having bonds in two different locations?

 

[alehman]

Yes, you need to remove the downstream bond. It is illegal per the NEC and may impair any ground fault detection relays.

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[waross]

What Alan said and it may also lead to the neutral current sharing on both the neutral conductor and the ground system, which is also a code violation.

Bill
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"Why not the best?"
Jimmy Carter

 

[davidbeach]

Ditto and third. Get rid of it yesterday, if not sooner.