Thanks a lot for the update,I shall go on holiday in September ,afterwards I seriously think about getting a second multi rs,even if they become not “multi’s” any more…..If I come up with some more questions ,can I ask You again:folded_hands:
Best regards from northern italy ,Frank
Enjoy your holidays. Sure community is there to help, I might spot your post by than
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So just to clarify…
You can parallel Multi RS Solar units at the AC output as long as you have no AC input connected on ANY of them (not even one of them).
Is that correct?
You can 3 phase but can’t parallel single phase.
You would have some funky voltages most likely without having them paralleled in the programming as they would be out of phase
But AvB mentions having 5 in parallel? How does that work?
Hi AvB,
Can you confirm that you have 5 multi rs solar units connect in single phase parallel at the AC output terminal?
Also, can you confirm that you can/cannot apply an AC input to even 1 of them in this configuration? (That would be really handy)
I have the feeling that’s an yes on both counts. 
Because MRS has the same hardware as Inverter RS and that can be parallelized, because doesn’t have AC-IN.
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That is indeed correct. When 5 Multi RS are grouped in parallel all on setting (L1, L2 or L3, which phase doesn’t matter it only matters that they are on configured on the same phase to be connected on AC-out) and system ID0 (That’s the default, but can be any other number. just the same number on each MRS that needs to be part of your singlephase group) than they become a group of inverter RS. No AC in possible.
An option is to add another multi RS and make it ID1 and set it at certain battery percentage to start charging from the grid. A bit expensive solution.
Quite a bit cheaper would be to use an MPII 48/5k or 8k to do the charging. I would suggest staying with MultiRS and in future and external relay to connect an external AC source will become available.
Is it possible to use 2 Multi RS connected to the same AC source (e.g. generator/shoreline via a 10kV transfer switch?) and the same 48V battery bank, so long as the AC outputs are kept separate?
Application is a boat, one RS would power induction hob/oven and the other the 230V mains.
If we are referring to Ian question above, he wants to parallel on the AC-IN, not AC-OUT.
He said explicitly… “AC outputs are kept separate”
And have only one battery for both.
In other words, two inverters sharing the same battery.
As the battery system is floating on the RS series, I believe this is doable.
I didn’t answered directly to Ian.
Connecting them together at the input doesn’t matter.
The main topic was about connecting them together at the output and that isn’t supported at the moment.
Just to be very clear. Yes both MultiRS are then configured as standalone. That will absolutely work and show up correctly on cerbogx and VRM
Indeed but downloading the public available Victonconnect Beta will give you the option to use Multi RS in parallel on the output, but than AC-IN is disabled on all the parallel inverters as there is no software yet for MultiRS to handle AC-inputs in parallel.
You’re right… The manual say so…
But remember, at some point, it said that it won’t work without a battery.
Numerous times Victron experts said that, because the manuals said that.
And look, now it works without battery, despite that.
The same hardware, without any modifications, can act as a PV inverter, without battery…
What should we believe ?..
That by miracle that device is now able of new things?
Or that Victron didn’t know what he designed and now suddenly realized that, without knowing, it designed a product that exceeded the initial expectations?
What I mean is that one can look at the hardware and firmware and see beyond a text on a manual and draw the conclusion that it’s not a problem to work in a certain configuration. So then, what to do?.. to follow the manual and play nice, or to dare the obvious?
It’s common practice to design a product with many things in mind, release an initial firmware with basic things tested and then, later, testing and verifying the design further, to come with additional things for (some of) the users to say “wow, what a great product/company!”… And this with minimal efforts, because the great humph was when the initial design took place.
Of course, the same users and/or the designers will say that was an epic battle because only the Ones have the silver sword and they finally managed to slay the dragon and now the time for songs and ballads of the great deeds are in order.
Just kidding (for some) or being sarcastic (for others)…
But really, let’s go beyond and dare to push the limits of both hardware and firmware.
My usual rant… Ignore me… 
Does that work with input current limiting? For example using a transfer switch with different current limits set for shoreline (16A) and generator (39A), how do the two Multi RS deal with this – is each set to half the current, ot do they behave as a single unit?
Matthias gave the correct answer with public stable hardware and software. Which should be the case for absolute most users.
However when you want to try new things than use beta software… For example the PV inverter functionality has been tested for over 2 years by many beta testers and is now publicly available. Same happens to other new functions like parallel on AC-out. Use Victronconnect Beta and enjoy it if you really need it. Many systems are “testing” this for years already and when firmware becomes available to do AC-in in parallel than within a few months it will become into public released VC. That is often how development works.
I think we all understand that – the big question is whether parallel operation will just be a firmware update, or whether it will need a new version of the hardware. If Victron know the answer to this it would be very helpful to say, even if they won’t commit to a date when it might happen…
That is indeed a good question… How much code does it take to make all inverters in parallel switch instantly from grid forming mode to grid following mode or in other words from Voltage generator to a current generator…. Will that extra code fit in current processor memory or is that going to be a hardware revision (read faster or bigger memory processor). I don’t know the answer to this question.
This would be replacing a single Quattro 48/10000 to get better efficiency and cooler running, especially when charging from the generator – I measure something like 12% loss (88% efficient) at 7kW input, plus it never get anywhere near the rated 140A charge current, this starts around 120A and drops to about 100A over an hour or so as it heats up, which is only about 5kW into the batteries. Given I have a 9kW generator this means much longer running time than it should be – the Multi RS should give something like 160A (80A each) which it should be able to maintain.
Does anyone know how efficient the Multi RS is when acting as a charger? The data sheet only quotes inverter efficiency, which is better than the MP or Quattro especially at high powers (94% at 5kW), but says nothing about charger efficiency…