I have a question about how to install MultiPlus-II inverters in a 3 phase configuration.
The 48V side is clear, but the AC side isn’t.
I also couldn’t find any info on this topic on the Victron website.
Maybe someone could advise me how this must be done according Dutch regulations.
Would like to make a 3 phase system that backups mine house.
Clear that the 3 inverters needs to communicate with each other and have to be programmed to be L1,L2 and L3.
Mine grid is fused by 3 C25 circuit brakers, and did see you can limit max input current of the MultiPlus-II, to prevent tripping them.
The battery (Victron system) can be placed a few meter from house fuse box, and a 6mm2 cable will do.
But how should I protect this cable to the 3 MunliPlus II, a C25 fuse and RCCB 300mA / RCBO?
And the RCCB should it be type A or B?
If one of the grid input phases fails, what will happen?
Will the other 2 MultiPlus-II also go in off grid mode or not?
If not the RCCB will trip at the moment the inverter of the missing phase switch from floating grid to hard grid (internal relays between ground an N).
Think this is unwanted, is a Phase Monitoring Relay needed to prevent this?
How must the output be fused?
If I use a 25A fuses it will never trip in off grid mode, simply because the inverters can’t make the current needed to trip them.
So would fusing the MultiPlus-II output make sense if this fuse can’t trip?
What will happen in case of a short, will this destroy the Multiplus?
Would adding a RCCB (at Victron side) make sense (because most shorts are from phase to ground), there are already RCCB in the house fuse box?
Is there any advice from Victron or community how to do this?
And how should the battery/ UPS be marked in the house fuse box?
Don’t have the latest NEN1010:2020 yet so (if there is info on this) I can’t look this up, maybe someone could advice?
And is there in the Netherlands a limit on battery capacity for residential use?
Ron
