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?