I agree that the feeder for a MH or MB is required to be 4-wire. However, if the conditions are all met, you could run a normal 3-wire setup into a disconnect inside of a mfg. home, and establish the grounding there. Of course if the manufacturer labels it as a 4-wire, then that is what is required. But then, they would not have installed the equipment in the method for allowing the inside disconnect, so that point is moot. Only if manufacturer has installed it is this allowed.
Also, all photos show a meter/breaker box combo, so the wiring between that box and the inside box would be a feeder, and it would be 4-wire per code.
I have not seen this j-box connection myself, but that does not mean it does not exist, or is not allowed. Let's not put personal feelings into reading the code. If it is installed per code, then it is allowable by code. I am sure there are numerous ways of routing the GEC outside of the structure, and using a j-box is just one example. Just leaving a loop of GEC stubbed out of the skin would be another. Installing some type of terminal might be another. The point is that to do so is allowable, if installed per the code.
Rick Miell
