From the Multiplus II block diagram it shows that the two AC outputs have a common Neutral. In a residential installation going up and down 4 floors, I am considering to have two different cables (AC1, AC2) and making a common neutral on each floor. I see in this forum that some are commenting that a common neutral may create issues with circuit breakers but I do not get the logic considering that already in the Multiplus II both neutrals are connected/common. Is there something I am missing?
Maybe they mean commoned between neutral in and out? That can cause a problem. [There is a grid code that supports it.] But obviously you can’t use that code if you have to adhere to a specific one.
(Since neutral is broken on grid disconnect and the ground relay activates when there is reconnect that is all tested.)
As you have said, it is common on the output and only line is broken on ac2 out. I don’t see an issue that way.
You can use a common neutral to wire ac out 1 and 2, but you will need to double it in size because it will need to be able to run amps from out 1 and 2
If you would go to the same distribution box from ac out 1 and 2 with a common neutral and have to place two, 2 pole circuit breakers (1 for ac out 1 and 1 for ac out 2) just split the neutral again at that point
Thank you both for the feedback, so a common neutral ac out is ok.
@DuivertNL doubling the diameter of the common neutral makes perfect sense, in this case I would have to pass a separate thicker neutral cable from a typical, let’s say 3x6mm2, to connect the floors.
From a practicality standpoint, what if, I use two same length 3x6mm2 cables connecting each floor (one for AC1 and one for AC2) and join their Neutrals in each distribution box (one per floor) onto a common neutral busbar. In each distribution box I can use the 2 pole circuit breakers to select either AC1 or AC2 for that particular circuit. My only concern is if the lengths are not identical it may overload one of them (the shorter one). Do you know if anyone has tried this successfully?
If not, the thicker common neutral would be my only safe option.