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No ground in panel 1987 Condo


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I recently did a 1987 6 story condo building where I found something interesting that I've never seen before even in other units in the same building. The main disconnect is at the meter and a three wire feeder to a sub-panel in the unit. Branch wiring is armored cable with white and black or red. There's no ground wires or ground bars. The outlets are three prong and are grounded to the metal box. I assume the ground is picked up through the metal conduit for the panel. With some research I've determined this was once acceptable, but I have some questions I want to better understand.

The GFCI breaker for the bathrooms will trip with the button, but not a tester. I assume this is normal and like using the neutral as a ground on an old cloth wrapped two wire system?

The sub panel is a Square "D" panel and it looks like the neutral bus is bonded to the panel still. Shouldn't this be removed?

Also, it looks like at some point a circuit was added and a green ground has been added to the neutral bar. Should this be removed and the metal box used as the ground? How should a new circuit be installed?



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It's still acceptable today to use the AC cable sheath as an equipment grounding conductor.

In the unit's sub panel, the bonding screw should be removed. If there's a green equipment grounding conductor, then an electrician should install an accessory grounding bar and land the green wire there.

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