I just came from an inspection that had a main panel and sub panel. The sub was fed from a 100 amp breaker in the main panel. They had moved most of the convenience circuits over the the sub. Here’s the twist: they only moved the ungrounded wires and neutral wires to the sub panel, the bare grounds were left in the main panel. These panels are adjacent to each other.
Does this work?
I was thinking along those lines. Since the conduit between the two is metallic, but installed in a concentric knock out I think Ill reccommend a bonding bushing and jumper back to the main panel. T
thanks for your input.
A bonding bushing is not required but that nipple in the photo is missing two locknuts between the panels and is improperly installed.
Electrically if the two panels are properly bonded leaving the EGC’s in one panel wouldn’t really matter, technically one could argue that it violates 300.3(B). Also you cannot use white conductors as ungrounded conductors unless they’re in a cable and re-identified.
Looks like a standard concentric KO to me which is permitted for bonding if the voltage to ground is 150 volts or less. The proper locknuts need to be installed on both sides of the threaded nipple.