sunshinepower avatar image

Configure Quattros for 2 phase operation.

Can someone tell me if two of quattros can be used together for 2 phase opperation. I have seen much about three phase but nothing about two phase.

quattro 10kva
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Hello, this is my first post.

I have 2 quattros 10kva, and I have 2 phase power on property, Can the 2 quattros be used together one on each phase with common neutral (as three phase would be connected) only two phases with two inverters.



As in split phase like America?

Or two of three phases to have backup power?

You can have one inverter on each phase running as a separate system.

Two inverters sharing one battery bank is a whole other issue and not supported.

I am in Australia, two phase not split, I have two phases not three. This is how the property is wired up, Two phases with a neutral. I have different appliances running off each of the two phases, 240v on each phase. And yes I also have batteries and they need to be incorporated into the system they are 48v lithium, I have 6 of them, Around 19kwh all together. I thought I had seen in videos with three phase systems with batteries as part of the system.

Is it impossible to have a 2 or 3 phase system sharing the same battery bank?

Do the batteries have to be broken up into two or three separate banks depending on if you are using three inverters for three phase or two inverters for two phase?

Thank you for your help. Greatly appreciated.


Please clarify "Two inverters sharing one battery bank is a whole other issue and not supported."

Victron schematic clearly shows a single battery bank powering two Quattros in split phase:'s.pdf


Two inverters configured as a split phase is one system.

I am referring to hanging two inverters up and electrically connected to one bank. That is not one system but two inverters with a shared battery.

This diagram shows a split system, I am wanting a two phase system. Both systems use two inverters but are different. I have not seen anything that comes from victron that shows a two phase system setup.
1 Answer
wkirby avatar image
wkirby answered ·
I think there has mostly been a misunderstanding of the question. I initialy thought you has three phase but wanted to only use two.

So if you only have two phases which are 120° / 240° then it is possible to have two Quattros in a system like this. The two Quattros can be configured as a two phase system with 120° / 240° phase separation.
Both of these Quattros configured as a two phase system MUST share the same battery bank, do not split the battery bank.

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Thats good to know, I am glad you can see how I want the set up to be now. However I am not sure what the phase separation is from the grid, I would presume it is 120 / 240, Are there instructions on how to do this?
bbmz avatar image bbmz sunshinepower ·
You need to be sure about this - this detail is very important. Probably talk to an electrician in your area.

Do you have your own transformator with two phases and one middle potential (SWER)? Or do you have a (normal) grid connection to a three-phase grid (but for whatever reason no connection to the third phase)? Both systems exist in Australia …

What @wkirby is referring to is the angle between the phases. In a three-phase system (where you can e.g. connect huge motors directly) there is a constant phase angle of 120 degree between the phases (e.g. Europe). In an split-phase system, the two phases are separated by an angle of 180 degrees.

This is the transformer that supplies my property.20220118-140851.jpg

This is in the electrical box on the side of house showing the power coming into the house. The top 2 are live connections 100 amps each and the lower neutral connection.20220118-142547.jpg

The phase angle detail is most important. Also where does your neutral come from and how is it derived?

You really need to have your electrician physically check and advise you on exactly what system you have.
It would not be good enough for someone on the internet to look at some pictures and give sound advice on something like this.

I know it needs to be checked to be sure and it will be, However I thought it might be obvious to people familiar, I am not so familiar but reasoning would suggest that because there is only two main wires going in to create two phases that have a neutral, that it would be a split system center tapped with ground connection which goes to ground down the pole and can be seen with an N on the pole.

Which would mean it would be 180 out of phase, center tapped is the neutral with earth connection. If this is indeed how the system is, as is highly likely how can two victron inverters be set up with this particular system.

I will be getting this checked properly but for now I would like to understand how two victron inverters can be used with this kind of mains connected system.


So for a 180° phase angle, two Quattros can be configured as pair.

They will be connected together electrically sharing a neutral and each line phase separate.
The two Quattros will also be linked with a VE.Bus connection for configuration as a split phase system and the VE.Bus communication between the two will ensure synchronisation.
Here is some documentation on how it works:

There are online training sessions in Victron Professional for more insight - links within the documentation as above.
Make sure your installes has experience with installing such Victron systems, they are complex and can be dangerous if done incorrectly.

Even though my supply may derive from a split system, I do not want to split the voltage with the inverters they need to supply 240v each not 120v.
You would select two 240V model of Quattro and have 240V line to neutral on each phase. 480V L1 to L2 (180° phase angle).

Is there a drawing of this set up.


I am an electrician in Adelaide South Australia. That picture of your transformer is set up as split phase (180 degree) not two phase (120 degree.). These two terms are always interchanged incorrectly in Australia. If you measure across your two actives with a multimeter you will have approximatley 480 volts for split phase 180 degree. If you had two phase 120 degree you will measure approximately 415 volts across your two active. Because your transformer only has two wires on the high voltage side you only have split phase 180 degree 480 volt.
Thanks Andrew thats what I thought it was as I have previously explained. I was hoping someone experienced would recognize the set up as you have done.