I am planning a new 100% off-grid 3-phase system for a home in Spain and planning out the loads across the phases, it will be impossible to get them balanced. If I use 1 x 5kW multiplus II per phase can it run completely unbalanced? e.g. L1=5kW, L2=200W, L3=0W
Secondly, if I already have a single phase generator, can I connect it up only to the most essential phase (L1) and have it pass through and charge the battery?
Finally, if I AC couple a 3-phase Fronius inverter on unbalanced phases will it automatically figure out where to send the power?
The biggest 3 phase load will be an air source heat pump, borehole pump and in the future EV charger. But right now, it will mostly be regular 1 phase household loads sprinkled across the phases as best I can. Reason for 3 phase is that it can handle larger EV chargers, and the distance to the pump is about 300m.
Please be aware, you cannot use all kinds of 3-phase loads. I think only star schema is allowed and not triangle. Please check the manual.
I use a 3-phase 2kw vacuum pump on 1-phase by using a 1-phase variable frequency device (VFD) to generate 3 phases. Might be a solution for the pump. Classic solution for long distance is increasing voltage by a transformator and lowering on the load side. This will also isolate the pump from the house.
Please mind, the MP2 5k can supply 4000W not 5000W at a temperature of 25C. In Spain you might need to cool it.
Yes, you can add unbalanced power sources, where a 1-phase generator is an extreme example. I use several 1-phase micro grid inverters (on ACout). They produce power on the single phase independently.
Please mind the factor 1-rule for Fronius and generator. Ensure the genertor does not start when Fronius is pushing a lot of energy and battery is full.