split phase Image

split phase

Three Phase System and Splitphase system from one LiFePo4 battery bank

Maybe it sounds strange.
I will build here in Panama a splitphase system with 2 Quattros. There will be a LiFePo4 battery with 290Ah/48V(600A max) with Lynx, Cerbo and MPPT RS.
Thats the easy part.
The battery is connected via VE.Can (its using the Pylontech protocol) to the Quattros.

But I have wood working machines from Austria, which run on three phases 380V.

Now the question:
Would it be possible to buy additional 3x Mulitplus 5000VA , configure as three phase, connect them seperate with the battery cables to the same Lynx (Distributor) system?
The second VenusOS could run on a Raspi. Maybe a smart shunt is needed for the Multiplus system?

As the MPPTs are loading the batteries (it distributes DC power to the system) it should work. Or, am I wrong?

Then I would have the split phase in my house and the three phase system in my workshop.

Of course it is expensive. But changing all the motors of the woodworking devices is also expensive.

btw: Can I use the Phoenix inverter smart 5000/48V. I mean can I configure it as three phase? Would be cheaper instead of 3 Multiplus...

Any concerns?
Thank you!

ps.: the workshop will be build new. Ie. the cables would be like in Europe additionally to the 120V in separate hoses.

mswoboda asked
mswoboda commented ·

2 Answers

Dual Multiplus II 2x120v units in split phase configuration

Can two Multiplus II 2x120v units be put in split phase configuration? The manual only describes using in parallel or three phase. I'm thinking of using just the L1 output from each inverter, similar to how the diagram shows for three phase operation. Any reason this wouldn't work?

solseekerssolar asked
overlandrvs answered ·

2 Answers

Adding additional 50A plug to MultiPlus II

I have a MultiPlus II 2x120 in my RV along with solar and 10.4kWh of LiFePO batteries. This system is incredibly flexible and provides a lot of benefits including the ability to operate for extended periods of time without hook-ups (shore power) and the ability to operate as if I had 50A service when I only have 30A.

I have added a PHEV to my vehicle line-up and would like the ability to share 50A service with the other electronics in my RV. I would like for the PHEV to have "priority" on the electric service if that makes sense -- it wants to draw 7.5kW when plugged in and I have a Level 2 charger with a 14-50R plug.

My thinking is that I will install a 14-50R receptacle in the RV that I can plug the Level 2 charger into. My question, though, is where to draw power from. One option would be to add a breaker and pull off of the same 50A service (shore power). If I do this, one issue I could have is drawing too much current from shore power unless the MultiPlus II knows about the Level 2 charger. I do have a current monitor but have never used it. Could I connect the current monitor on the main feed from shore power and then parallel the MultiPlus II and the 14-50R for the charger. Would the MultiPlus II restrict it's current knowing how much total current is being drawn and the limit in the MPII?

Another option would be to put the plug on the output of the MultiPlus II. I don't expect to be able to charge without any shore power (my PHEV has a 17.2kWh capacity and my RV only 10.4kWh so it makes no sense to let it draw down the battery if I'm not on shore power). My MPII is a 3kVA unit, but I believe this is just the rating for the inverter. If I was plugged into a 30A service (providing only 3kW of power), the MPII can only make up another 3kW so I'm shy of the current required to charge the PHEV, BUT my charger will allow me to lower it's current draw so I could set that at say 5kW and allow it to charge from both batteries and the shore power. This would allow me to quick-charge the vehicle (this would take about 3h at that rate), draining the batteries some during that time and then when I leave in the vehicle, the MPII would continue to charge the batteries in the RV from the 30A shore power.

Has anyone tried this? Any ideas on the best approach? I've attached a drawing of my current setup without the PHEV power connection for reference.

390RK Solar-11.drawio.pdf

xxn5ac asked
markus-001 edited ·

1 Answer

2 x Multiplus 2 in 2-phase ESS configuration on 230V IT (3-Phase Delta Norway)


I know that 3-Phase Delta is not supported. But what about using 2 inverters in a 2-phase configuration with 120 degrees shift? The goal is to be able to feed in more than the max 16A on a single phase limitation we have here in Norway, and still be able to control everything from one single Cerbo. I have no need for a real 3-phase network on the back side of the Multis. Some single phase critical load on one of them is basically enough. The second Multi should only act as a grid-tie inverter on a different phase to even out the power between the phases.

I got this drawing from a Norwegian Victron distributor. I assume it comes from Victron. I understood that this was somehow tested, and it works. There were some instabilities in the voltage on large load variations between L1 and L3, but except from that it worked. This setup may work in an non-ESS environment, since you can disable the N-PE ground relay. In ESS-mode you cannot disable the relay, and you will short L2 and L3 to PE on the output. The picture also states that "Ground/PE must not be joined"


So what if we modify the above slightly to something like this:


It is possible that the phase rotation will be wrong on the second unit. I'm not sure, but if we assume this is ok, this would allow ESS and feedback. In case of a grid failure, it will look like this:


The internal relays will disconnect the inputs. The ground relay will kick in and join N and PE. Since we here have a common phase for N (the L3), this will not short out anything. It will create 2 separate single phase TN networks on the output. As long as you don't connect any load between the 2 inverters I cannot see that that is more problematic than running one single unit, which works fine.

Can anyone here confirm if above solution will work or not?


oet asked
oet answered ·

2 Answers

Fronius and Victron split phase

Is it possible to use a Fronius inverter with the 120V/240V split phase system?
And is it possible to run the Fronius on 60Hz?

mswoboda asked
mswoboda edited ·

3 Answers

Using U.S. split phase to power single phase Multiplus

We work in Congo, Africa, and receive 3 phase 220Vac from the grid. However, due to the constant and lengthy power outages, I'd like to run my single phase 220Vac Multiplus off of a backup generator. Unfortunately, the generator provides "split phase" 220Vac as what you would find at the outlet of a drier in the U.S. The inverter refuses to recognize the input and has a bottom input threshold of 180Vac, blocking me from using it in its current configuration or from using one 110Vac leg of the generator output to power it. Here in a remote jungle village, we always have to improvise, so I am looking for a solution, understanding that it might not follow normal practice or meet "code". Thanks for the help

johncongo asked
kevgermany answered ·

1 Answer

Dual phase angle

I am putting together a dual phase system using 2x 48/10000 Multiplus II for a client who is supplied 3 phase from grid, but only uses 2 of the phases. When commissioning, what phase angle would be required?

ross-skyenergy asked
Kevin Windrem answered ·

1 Answer

Design of a split phase system 120/240V 60Hz with Victron Quattros

Hi to the community!

We want to build a split phase system 240/240V 60Hz (located in Panama) with Victron Quattros of at least 30kW.

My question is which Quattros I should choose and if an Autotransformer makes sense.

I have to explain what the system should be able to do:
We want to run a wooden dry chamber (theoretic maximum of 20kW) consists of different devices. Most of the time its should not exceed 13kW, but theoretical 20kW are possible for a short term. All devices are 240V/60Hz

Furthermore there will be a small carpenter workshop, with different machines. The machines (all of them are 240V) in the workshop won’t run at the same time. The maximum of one machine is 4kW on 240V.

For the 120V will be the light and maybe small tools like a drill machine, but again, not many machines at the same time. So I think, not more than 1200W.

Initially we wanted to take two of the 15kW Quattros split phase (30kW) but I noticed in the beginning that the 15kW model is only in 240V available. (Later on I noticed in the manual that it is possible to order a model 15kW with 120V, I have to find out if I can get this model).

So I have three options for the topology:

1. Suppose I get the 15kW model with 120V, I would have two of them as a split phase system. I don’t think that I run into a balancing troubles (between the 120V phases), because the heavy loads run on 240V.

2. If I don’t get the Quattro 15kW 120V model, I have to take 4 of the Quattro 8kW models. Two in parallel and split phase. So I would have 32kW power at the maximum. Of course more expensive and more work with AC cable wiring!

3. Suppose I take two of the 15kW 240V Quattros and I will use a Victron Autotransformer (100A) and still most of the most loads are 240V, will the Autotransformer be the right solution? I mean, the Autotransformer makes it possible to use the 240V Quattros and is balancing the two 120V phases (if I understand the function of an Autotransformer in the right way).

The rest of the system (beside the inverters) will be the following:

- 55 kWP module power with a few MPPT RS (I have to do the calculation with the Victron Excel, if I have the data sheet of the modules)

- 176kWh LiFePo4 batteries (15 pieces in parallel with 48V/230Ah connected with copper busbar)

- Lynx system, Cerbo, all connected via VE.Can
- ESS, the system should be capable to feedback electricity if the dry chamber/workshop is not used

- A generator (have to think about the size) if there is a power outage and the batteries will deplete

I am a technical engineer and I build up a three phase system in Austria (3x220/50Hz) with 3xMultis 5kW, 15kWP and a self built LiFePo4 battery (560Ah@48V). So I am new to split phase and electricity in general here in America.

I am happy about your recommendations or comments!


mswoboda asked
shaneyake commented ·

3 Answers

Inverter data reported to Cerbo incorrect, dual Multiplus II system

The system is made up of dual Multiplus II units in split phase (180 degrees), wired to a Victron Autotransformer (for inverter output balancing).

When connected to grid, in this case 50 amp split phase, L1 is displayed at zero or slightly negative on both input and output. L2 is displayed correctly. When inverting both L1 and L2 are displayed correctly on the output.

In previous systems using the regular Multiplus or Quattro, this issue has not been present.

Screen shots below taken moments apart. Same load throughout.


with grid power


without grid, same load


solseekerssolar asked

0 Answers

MultiPlus 12/2000 split phase not entering charger mode

Two Multiplus 12/2000 with same firmware and wired as split phase. Inverter 1 (master) is on phase 3, Inverter 2 (slave) is on phase 1. Phase 2 is not being used due to poor power factor. On occasion, after grid power is restored, they will not return to charger mode. I have unchecked "switched as group", and the Phase 2 is set a floating with return to normal. I am using one 12V Relion 100Ahr LiFePO4 battery. Some times the system works normally, other times the Mulit's will not return to charger mode.

On another note, I can only get the system working using the Split Phase 240 setting.

karl-crossman asked

0 Answers

Using AutoTransformer to create 120v/240v split phase from single phase 120v input

I have a use-case for the AutoTransformer that is different from what I see generally discussed. I want to use it in my RV to take in 120v 60 Hz from either my Onan Generator (2 separate 120v legs that are SAME phase) or the shore power inlet (30/15 Amp which are 120v 60Hz single phase). I have those 2 inputs going to an automatic transfer switch so whichever one is "on" will pass through to the AutoTransformer. I would like for the AutoTransformer to step up the voltage from 120v single phase to 120v/240v split phase. I will then pass that split phase into the input side of my dual inverters (one inverter for each 120v leg) so that when I have a single leg input, I still get both inverters charging instead of one side passing through voltage and the other rejecting the phase and inverting to make the "correct" phase.

So, my question is, how should this be wired up to the inverter. It has labeled "input" and "output" sides but the "input" side only has 240v Line and Neutral labeled connectors. The "output" side has 120v Line 1, Neutral, 120v Line 2 connectors.

My intuition tells me to disregard the input/output labeling and connect my source 120v power with:

source 120v Line > AutoTransformer "output" Neutral

source Neutral > AutoTransformer "output" 120v Line 1

Then my output would be the 240v wave form stepped up via transformer as measured between the "input" Neutral and "input 240v Line connectors. I would need to carry over the neutral from the other side to provide 120v/240v split phase.

It is this last part I am unsure of and need some guidance on.


Diagram attached of my planned whole system that hopefully makes clear what I am trying to achieve.


cookinwitdiesel asked
Greg Melton answered ·

3 Answers

Failure of one Multi in 3p config - fast path to temporary restore?

Situation: 3p configuration of 3 Multiplus or Quattro devices.

Everything works fine, until it doesn't. Now one of them goes kaboom for internal reasons (i.e. device failure).

As soon as that happens, the whole system goes down "of course". Now the question is, how does one proceed to restore at least partial operation until the faulty device comes back from repair. Two phases could work which is better than 0 phases.

Assume the faulty device has been taken offline, and there are 2 - potentially working - devices left. until the faulty device is sent back, repaired and sent back-back it will take a week. What now?

Configure the remaining 2 Multis for parallel configuration is not going to cut it as they have different AC Outs - yes/no?

Simply turning off "switch as group" will also not cut it, because there still is one missing for a 3p config?

Reconfigure for 2p operation?

Is there a manual how to proceed for these cases?

petajoule asked
nickdb commented ·

2 Answers

Mixing 2000va and 3000va Multiplus II in split phase

Can I use different models of Multiplus II (e.g. 2000va and 3000va) to create a split phase output between the two? Or do they have to be the same model?

artvladi asked
wkirby answered ·

1 Answer

HOW DO I: 120V Single Phase --> 120/240V Split Phase ??

I need to go from 120V Single Phase (either 15A or 30A depending on the source), to 120/240V Split Phase. My inverter charger has both L1 and L2 available so I'm assuming L2 isn't optional.

I'm assuming a single AutoTransformer will step up 120V single phase into 240V single phase, not split phase....but if I'm wrong, then all my problems are solved!

My questions are:

- can a second autotransformer turn 240V Single Phase into 120/240 Split Phase?

- can a single AutoTransformer be modified to go straight from 120V single to 120/240 split?

- is there another device I should be looking at entirely?

Thanks community! I don't know why this specific answer is so hard to find.

dothedr3w asked
dothedr3w edited ·

2 Answers

Skylla-IP44 12/60 input power - 240VAC Split Phase?

I'm using a Skylla-IP44 12/60 to assist my MultiPlus-II 2x120 in charging but only want the Skylla to charge when the generator is running. My generator produces 240VAC split phase, my shore power is 120VAC only. If I power the Skylla off of L1 and L2 of the AC Out 2 on the Multi-Plus II it would only see power when the generator is running and not when I am plugged into shore power. Can the Skylla-IP44 12/60 accept two split phase hots instead of the hot and neutral as indicated in the diagram in the manual?



thedeltaskipper asked

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