When the service cable runs from the meter to an exterior disconnect, then through the wall to the indoor panel, does the short piece of service cable that runs through the wall have to include a ground (or can it just be 2 hots and a neutral)? And does the answer change if the exterior disconnect is a breaker rather than just a switch?
I’m asking because I sometimes see an exterior 150-200Amp breaker (or maybe it’s just a switch/disconnect) and then on the other side of the wall I see a 150-200Amp breaker in the panel.
It seems to me if the wire through the wall is 2 hots, a neutral, and a ground, then the indoor panel becomes a subpanel that must have separate neutrals and grounds. Whereas, if the wire through the wall is just 2 hots and a neutral, then the indoor panel does not need to have grounds and neutrals separated.