I’ve done some research and can’t find a definitive answer.
I have a duplex (Rowhome split into two units) that has one overhead service cable that feeds down to two meters and there are two main panels (1 for each unit) in the basement. Each panel has a ground wire that comes out of the top of the panel and goes its own way, but there is a wire linking the two ground wires. So, my question is, is this correct or a safety issue?
If something happens in one electrical system and current makes its way to the ground wire and comes out of that panel, but then finds its way into the other panel…
As far as I know, the two panels can share a GES. Basically, as Kevin said above, one of the grounds might be going to the water pipe and the other to a ground rod. The combination of the two is one complete GES. And both panels are sharing that system.
If the grounding electrode system was installed correctly, with these two systems properly bonded, any stray current should go to the grounding electrode/ground rod.
It looks like the boding screw (green screw) on each panel have been removed. They should be there for independently derived systems as these appear to be.
The bigger issue here is the lack of an insulated neutral wire. The 120v circuits are using the un-insulated ground. Yes, I realize they go to the same ultimate place but this would never pass a codes inspection.
I am referring to a qualified licensed electrician.
That’s a common arrangement; though, your concerns are valid. I was hired recently by a duplex owner whose tenants were fighting over electricity. One was accusing the other of stealing his electricity. I traced out every circuit in both panels. What I found was that the tenant being accused of stealing electricity wasn’t. It was, in fact, the reverse. The tenant doing the accusing actually had circuits originating in the accused tenant’s panel.
I don’t think either of them were guilty of stealing though. The work had been done a long time ago, since before the current owner owned the place, and probably before either tenant had lived there. Also, after interviewing the tenants in both units, I didn’t think that either set of tenants knew enough to steal electricity from the other.
