I’m in the US. We have a generator inlet connected to an interlock switch. In an emergency we can connect a generator and power the house through this inlet and interlock. The interlock makes it so that the main breaker must be off for power to enter through the generator inlet. The generator inlet is connected to our main panel (not a critical loads panel). As one would expect there is a neutral-ground bond in that main panel. In this arrangement one is supposed to use a generator that does not have a neutral-ground bond.
We also have a camper with a Multiplus II, solar, and batteries. This is connected to grid power through an outlet on the house (for charging in addition to solar). The power outlets in the camper are connected to AC-out-1.
I would like to use the camper to provide emergency power through the generator inlet. Essentially this would mean "plugging the house into the camper" and having that power distributed through the main panel (we would switch large loads in the house off by turning off their breakers).
In the event of a grid power failure I would unplug the multiplus II from the house. I would isolate the house from the grid by flipping the interlock, then I would then connect AC-out-2 to the generator inlet. I would then turn on the Inverter on the Multiplus II.
Two questions:
1. Given there is a neutral-ground bond in the main panel, my understanding is that there should not be one in the Multiplus II. By default, though, when disconnected from the grid and the inverter on, the ground relay makes a neutral-ground bond. I can turn that off using veconfigure. Is that the right thing to do?
2. If I turn off the neutral-ground bond, will the camper outlets (connected to AC-out-1) be grounded through the neutral-ground bond in the main panel? ie. does the neutral-ground bond "downstream"
of AC-out-2 also work for things connected to AC-out-1, if the ground-relay is disconnected. I think it probably does?
And then two more questions:
1. I think I can use a programmable relay to turn on AC-out-2. I've tested that via veconfigure assistant and indeed power is present at AC-out-2 when the inverter is active (unlike the default).
2. Can the ground relay also be controlled by a programmable relay? I can't see a way to do that in veconfigure. If it can't, then I'd have to hook up veconfigure when the grid went down?
3. Can both of those relays be controlled by the Cerbo GX? Does that require wiring from the Cerbo GX relay to the Multiplus II aux relay? ie the programmable relays can't be triggered through VE.Bus?
Essentially I'd want two modes for the camper, one like the current default setup (AC-out-1 active, ground-neutral bond present if AC-in is unplugged ("camper mode"), and one where AC-2 is active and the ground-neutral bond is never present ("generator mode").
I understand that it would be bad if the system was in "generator mode" but the AC-2 connection to the house main panel was not made (as there would be no neutral-ground connection but the inverter would be providing power). I would avoid that, but I think it helps that all of the outlets connected to AC-out-1 are GFCI protected?
