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3 Phase (380V) MultuPlusII - information / video please


I am new to Victron Community and have done 6 Victron solar installations - all single phase.

I now have a 3 phase, 380V with 3 MultiPlus II's solar installation coming up and need to prepare myself properly. I have done extensive internet searches for training or "how to" video's in this regard, and found just 1 video and then the Victron Parallel & Three Phase VE.Bus Systems manual.

Don't know if my search term is incorrect, since there are many ways to write "3 phase", eg 3-phase, 3 phase, three phase, 3PH.

I would appreciate it if anyone can point me in the right direction, where I can find such videos.

Thank you very much!


Multiplus-II3 phase
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3 Answers
ee21 avatar image
ee21 answered ·

Okay, I think I have enough information to provide you an answer, however let me first start by stating for the record, that I am neither a licensed electrician, nor Victron equipment installer, merely an avid DIYer with a talent for electricity. If anyone with such certifications wishes to correct anything I have said here, please do...

That being said, what you are describing sounds like a fairly typically 4-Wire (plus GND depending) Wye installation. Before attempting to configure this, please familiarize yourself with the requirements and stipulations of installing a 3-phase/parallel system:

Assuming you are following those guidelines regarding DC wiring, etc... to perform the actual configuration of the VE.Bus system you are attempting to install, I think it would be appropriate to start with the VE Quick Configure Utility at first (bear with me). Using this utility, start with a "new VE Bus System", select 3-Phase, click "Show Picture", and ensure you have the communication wiring between all the components wired as shown, click next, ensure all inverters are in the "off" position, any AC Input has been shutoff, AND any AC Output has been disconnected as well! Pick the right COM port your MK3 USB is using (I can help with this if you need it), click next and follow the instructions. The first inverter you switch on will become your L1, second will be the L2 and so on. This will be important for your phase rotation, I recommend you label them, more on this later though.. Once all three units have been powered on and recognized by the utility, click done and save. You should now have a 3-phase system running off of DC power. Take a multimeter and measure voltages across L1+L2, L2+L3, L1+L3, L1+N, L2+N and L3+N. Ensure these are consistent with each other. I believe the default will be 230V on each phase-to-N, and around 400V phase-to-phase. This can be adjusted after the fact using VE Configure as needed, but this may be what you are looking for already. To get specific, you mentioned each individual phase will be 230V, however you mentioned phase to-phase is 380V, which I do not think is totally accurate. Based on my math, and how 3-phase works, the phase-to-phase voltage should equate to (L1-to-GND voltage) * (Square root of 3). If your single phase voltage is 230V, phase-to-phase should be ~400V, however if single phase voltage is 220V, then phase-to-phase would be ~380V. So basically this is up to you what you want it to be, but to adjust it, you would alter the Output Voltage in the "Inverter" settings tab of each unit (they MUST be all 3 set the same, else I suspect bad things will happen), set to 220V if you want phase-to-phase=380V, or 230V if you want phase-to-phase=400V.

At this point I would advise you test a 3-phase load, while still running in inverter mode off the DC bus. Most 3-phase loads will be unaffected by the rotation with the exception of a motor. If you have a motor I would test this to make sure it spins the right direction. You should simply be able to connect the load's L1 to inverter L1, L2 to L2, etc.. If however the motor spins backward, it may be looking for an A-C-B rotation. I think you should be able to swap the motors L2 and L3 to correct this.

Assuming that all goes well, now its time to try your AC Input. Shutoff the AC Output again before doing so. Now, if your genset outputs three-phase in a wye split, you should again be able to connect the genset L1 out to Inverter L1 AC In, and so on. Tie the genset N together with all three inverter N, and same with GND if there is one. Before starting the generator, connect to your GX device, go to your MultiPlus (there will be only one listed even though there physically are 3, that's okay), scroll down and view the error screen; this hopefully will help you if it doesn't like the AC input... Now it's time to cross your fingers and fire up the gen. If all goes well, in about a minute after the voltage stabilizes, you should hear a very loud click, as the internal transfer switch in the inverters activate... Otherwise, check your GX to see what the error is, most likely it will be the phase rotation if the output happens to be A-C-B. In this case you should be able to again just swap the L2 and L3 hopefully (after shutting off the gen!). Now try it all together! See if the AC Output loads work as expected when the AC Input is active.

Hope this helps! I followed a very similar procedure when configuring a split-phase (2-phase) 180* setup.

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Hi ee21,

Thank you for your detailed and comprehensive answer.

With regards to 220V, 380V or 230V, 400V, it is the latter. Many farmers speak of 380V, which is technically incorrect. It should be 400V.

Perfect, than you should be fine with the default inverter setting of 230v/phase. The only thing you need to worry about is whether the rotation is A-B-C or A-C-B, which I think is fairly easy to correct. I live in the US where three-phase isn't really a thing, apologies for my lack of 100% certainty on that aspect.

JohnC avatar image
JohnC answered ·

Hi Anita. Try signing/logging in to Victron Professional. Hopefully my data gets scrubbed outta that link, I can't remove it from here. There's training stuff in there that I can't speak for, but might help..

And my Google has learnt my habits. Everything I type that it can link with Victron it will cough. The depth of info is incredible.

Have fun.. :)

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Hi John,

Thank you for your response. Believe it or not, but I am on Victron Professional and couldn't find anything there either. :-(

There are loads of other training stuff tough. Very good.

As I said, maybe my search terms are not correct??



A step by step three phase installation video for Victron Professionals is currently in pre-production.

It should be ready in a few months.

Anita avatar image Anita Guy Stewart (Victron Community Manager) ♦♦ ·

Thank you Guy, that's good to hear!

Look forward to seeing it, although by that time, this installation would be done.

ee21 avatar image
ee21 answered ·

You would need to be a little more specific about the system you are installing. When you say 380V, is that referring to your PV DC output voltage? Or is that the maximum voltage AC across two phases? Is the solar going to be connected via DC charge controller, or AC PV inverter? And what specifically is the question you are asking? It sounds like you are experienced with the solar aspect, and are looking specifically for information on how to configure a 3-phase inverter setup?

I would need more information about the incoming utility electric, I installed a split-phase system in my own home (2-phase, 3 wire, 180* phase angle) where L1+N = 120VAC, L2+N=120VAC, and L1+L2=240VAC. When you say "3-phase" I am assuming this is 4-wire utility service, with L1, L2, L3, and N with a 120* phase angle? This should be somewhat straightforward, I would recommend running the VEBusQuickConfigure in Demo mode to get a feel for setting up a 3-phase system. To keep it brief however, Inverter A would connect to L1+N+GND, inverter B would connect to L2+N+GND, and inverter C would connect to L3+N+GND in this scenario though. As far as the AC output goes, follow the same logic, if you are connecting a sub-panel to the AC out, then Inverter A L1 Out to sub-panel L1 In, etc. Tie all the Inverter N outputs together, and then leg that over to the sub-panel N bus.

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Hi ee21,

Thank you for your response.

Yes I am referring to what you describe in your second paragraph.

380V AC on the output side. It is for an off-grid farm where they have 3 phase AC machines. And each individual phase (single phase) will be 230V.

And yes, the solar side is sorted. 3 x 5kVa MultiPlus II, with 44 x 325Wp PV modules, and 3 x SmartSolar 250/100 MPPT's, a CCGX and BMV.

There is no incoming utility electricity, but there will be a 22kVa 3 phase generator as back-up.

So it is just the 3 phase configuration and related requirements that I am looking for.

I have played a bit with the VEBusQuick Configure, but is not sure of that is all that there is to it.

What I know so far, is that the actually setup / configuration of 3 phase is fairly straight forward, but that the phase rotation is where the challenges comes in.

Was hoping to learn as much as possible about both ( configuration and phase rotation).