Originally Posted by
Ed Voytovich
Jerry: Is this the case even if the panel and subpanels are electrically bonded by rigid metal conduit between them?
Yes.
Even if the service equipment enclosure and the panel enclosure are bolted together (but not made as one by the manufacturer) and the wires go through a closed chase nipple (the shortest nipple available) - yes, they are two distinct enclosures and two distinct pieces of electrical equipment, with a separate neutral and ground path running between them.
With combination service equipment / panels in one enclosure, then they are made to be used either as "Suitable For Use As Service Equipment Only" or as "Suitable For Use As Service Equipment" - the difference being that in the "Suitable For Use As Service Equipment Only" enclosure, the neutral *IS* bonded to the enclosure/ground and there is no way to change it.
In "Suitable For Use As Service Equipment" enclosures, the neutral is isolated from the enclosure/ground and must be bonded to the enclosure when used as "service equipment".