I have been using my Victron system for 3 years now without any problems.
The setup is as follows:
3x MultiPlus II 48/3000 (as a 3-phase system), 2 DIY battery packs (China, Eve) with around 14 kWh each.
The cables run directly from the public mains supply to the MultiPlus units and then via AC-out1 back into the distribution board to supply the house.
I live in a detached house with two people.
In the records, I keep seeing that one phase or another temporarily “uses” 3,400 W or even 4,200 W (when all the hobs are on while cooking, and perhaps the sauna is running as well).
As I said, there haven’t been any problems so far.
Now to my question: I know that the MultiPlus II 48/3000 can deliver a maximum of 2,400/3,000 W. My thinking so far has been that if I temporarily have a higher consumption, the difference will be drawn directly from the public grid.
But is that assumption correct? Is that how it works?
Or have I simply been lucky so far, and should I replace my 48/3000 units with 48/5000 units for the future?
Maximum feed through of 48/3000 is 32A. It tries to compensate your consumption by “injecting” power so that current stays at 0A. If it can’t (maximum power reached or batteries are discharged), current will just flow through your MP II up to allowed 32A. You should also have a 32A circuit breaker on the AC in, which would protect against overloads.
What power is your sauna? I would recommend connecting it on the AC in side. But then you will also need an external energy meter for your MP II to know when sauna is on.
Hi Heiko, simply check the GX display or the remote console to see whether additional power is being drawn from the public grid to cover your consumption.
Within its technical limits, the Victron system attempts to keep the SUM of the power across all three phases at zero. See ESS manual 7.3.
There is also the imbalance load regulation for Germany, limited to 4.6 kW.
For a normal ESS system, in my view it makes little sense to design it to cover all peak loads. The grid acts as a buffer for high loads (cooker, instantaneous water heater, etc.).
In your configuration, however, the limit is 32 A per phase, since you are using AC out.
For many households, a 3000 or 5000 model on AC in is more than sufficient.
In addition to the cost of the Multiplus unit(s), cables, busbars, etc., the devices’ higher power consumption also comes into play.
Image: Almost all consumption is covered by AC PV or the Multiplus; only the power for the instantaneous water heater is drawn from the grid in the evening.
Many thanks for your replies — so I’ve understood it correctly after all. More power can also be made available than the 2,400/3,000 W provided by the MultiPluses.
That’s how I understood it too.
I’ve never had any problems so far, and my sauna is only a small infrared sauna that doesn’t draw all that much power.
Everything is adequately protected by circuit breakers.
In that case, I won’t update my devices either. There’s no need.
In the event of a power cut, Victron immediately switches off a large contactor, which instantly disconnects the high-power consumers (heat pump, cooker, sauna).
With this emergency configuration, the 48/3000 units also provide enough power for the refrigerators, roller shutters, a few sockets and two important pumps.
So, in island mode, 2.4 kW per phase can be supplied continuously, 130% for 30 minutes, and considerably more for short periods. In other words, with a little common sense, you can simply carry on with normal everyday life.
Including cooking, using the washing machine, etc.
You do have to forgo using genuine high-load appliances.
This only applies to the loads connected to AC out 2.
