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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

Multiplus2 on only 1phase in a 3-phase house system


Is it possible to install a MultiPlus-II 48/3000/35-32 combined with a single phase PV and Battery on only one phase of a 3-phase-grid house system? Target: Reduce cost compared to a 3-phase-system, but still have a backup in case of grid power loss. All the critical loads in the house are connected to that one phase. There are no specific 3-phase-loads in the house used.

I ask, since so far I've not seen in any description duch a system design...Thanks for any advice!

smilyboy asked
marekp answered ·

1 Answer

Configuring a Three Phase

We have connected a three phase 5KVA multiplus-II system.

the inverters are updated, now we want to configure them, we doing so without wiring the AC in but with the 480V battery wired up.

when we switch on the first one its ok but when the second one is switched on it starts beeping and the "absorption LED" lights up same with the third inverter, and we get error code 3.

Any assistance will be appreciated.

Lindsay asked
nickdb commented ·

2 Answers

Multimeter short betwen (Lines) L1 & L2

Can anyone assist me with this, I think I'm missing something.

We wired and configured successfully a three phase multiplus 5KVA inverter. When it's switched off and using a multimeter reading ACout 2 between L1& L2 (lines) I'm getting a short is this normal?

When we switch it on and reading between L1 & N (phases) I'm getting the 230 which is acceptable.

Lindsay asked
Kevin Windrem answered ·

3 Answers

ACout Short between lines (ACout 2 L1&L2)

Can anyone assist me with this, I think I'm missing something.

We wired and configured successfully a three phase multiplus 5KVA inverter. When it's switched off and using a multimeter reading ACout 2 between L1& L2 (lines) I'm getting a short is this normal?

When we switch it on and reading between L1 & N (phases) I'm getting the 230 which is acceptable.


Lindsay asked
Paul B answered ·

1 Answer

MP II + 3 phase converter transformer VS 3xMP in 3phase wiring + phase converter transformer ?

Hi. I have a small farm in which I have various pumps, biggest one for now is 4.5Kw. I also have a house nearby and I'm considering getting a solar system given the provoked .....Erm, sorry I mean the current energy crisis... :) Anyway, all the pumps are 3 phase, the house is single phase. My initial thoughts were to get 3 Multipluses 3000 48 and set them in 3 phase, but then I remembered that I'd have to be very carefull because of a water heater and oven in the house, that together surely surpass the MP's 2400W rating. Now I found about 2 companies that sell transformers to the industry and they have 3phase to 1 phase converter tranformers and also vice versa!! For 5Kw those things weight more than 50Kgs !! But they cost about 2/3 of a single new MP.

The other option , which I'm pending to right now, is to get a single higher wattage MP (i.e. the 8000 48 version or even the 10000, although that is probably overkill and has too much losses for my taste, was thinking of minimizing the battery size for now) and put a single to 3 phase converter transformer in the circuit for the pumps.

Question is, which one would be preferable ? I know using transformers to make the conversion, one way or another, is going to incur in losses, does anyone have any experience with this ? The companies do provide a datasheet but they don't include the efficiency and why should I trust them for that anyway, the efficiencies for transformers are probably known in general.... Here is a link with an example:

Going with a single MP would be better in terms of future maintenance / repairs / replacement (although this shouldn't be a factor with Victron, given the higher quality, but eventually anything can die), given that if I have 3 MP wired for 3 phase and one of them goes wrong, I'd have to find a replacement with exactly the same model, whereas with a single bigger one I could borrow one / have a spare / more easily...

One advantage however if I go the path of 3MP wired in 3 phase is if one inverter malfunctions I would
still have the other two to feed the single phase circuits in the house, and could even wire it in parallel with the other one.

Decisions ....

But yeah, I'd like to know the potential transformer losses of the phase converter transformers and if anyone has any experience with this...

Also, another option would be 3 MPs wired for 3 phase and a separate MP for the house, no transformer losses then, although it's more expensive... In this case I could also go with smaller MPs for the 3 phase wiring...

What do you guys suggest ?

Thanks a lot!

jven asked
jven edited ·

2 Answers

Paraller phasing of two MultiplusII 5KVA for one phase system it is possible ???


I have a single phase off grid system on an MPII 5KVA using the SOC generator function to switch via ATS to the distribution network (I don't use it as a generator!!! If the PV is disconnected (SOC) the whole system is connected to the distribution network. "Please don't confuse this with a generator" ). I am satisfied with this solution.
But I would like to increase the 1 phase power from 20A to 40A by parallel wiring and keep the wiring I have (if possible). In the prospect documentation it is written that it is possible to connect up to 6 pieces of MP-II (parallel). Honestly, I'm not quite sure how to connect it :) So maybe you can guide me if I'm doing it right...
Question about connecting two pieces of MPII in parallel (one phase):

a) From MPII (Slave) AC OUT1 I bring the cables to MPII (Master) AC IN, since I do not use the distribution network via victron (we don't have to solve why).
b) Or MPII (Master) AC out I will send the cable to MPII (Slave) AC In - but here I have a feeling that the Master-Slave logic will change :)
How to actually wire it properly???
If I'm not mistaken, I have two options to connect and configure?
1) is a generator where additional MPii are connected from a certain load
2) parallel phasing - this seems like a more reasonable solution to me, but I haven't been able to find out how it works in practice yet.

Regarding the following configuration (ve.config), I found something regarding parallel connection via ve.config. I will document later.

Thanks for advice.

Juraj Nikolov asked
Juraj Nikolov commented ·

1 Answer

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

Three phase scheme

Hello everyone, I,m new at Victron community and I,d like your help in a photovoltaic project which I,m dealing.

I,m taking some online training at Victron professional and I guess I,m learning, But I would like to share my case to hear yours opinions

I need a 3 phase off grid system with a ESS (30kwh possibly to up to 60kwh), to be installed at a single home. I understand that a gasoil/gasoline generator will be needed in case of emergency.

The AC loads could be around 40-60 kWh/day, and the peak consumption around 10 kw.

The power of solar panels installed around 18 kw.

A future conexión to the grid is possible.

I would like to hear your opinion about the best efficient system, (with newest Victron equipment actually) Thank you very much.

rafavictron asked
rafavictron edited ·

2 Answers

Generator to DC side of 3-phase grid connected system

Hi dear Victron community!

I have a grid connected three phase AC-out-coupled system with Multiplus-II, CerboGX, SmartShunt, Lynx distributor and battery balancers. Battery pack is 48V 600Ah made from 12 pcs of 12V lead acid GEL batteries (picture below).


I would like to connect a back-up generator for the wintertime to help the batteries when the electricity price is really high and the SOC is getting low. There is three possible solutions in my mind.

1. Generator and changover switch to AC in of MPII. That needs a very powerful 3-phase generator which is expensive and there are troubles with feed-in.

2. Generator and Skylla charger to the DC side. Not a big generator needed but there is no VE.bus communication with the system.

3. Generator and another Multiplus (preferred). This way I could have intelligent communication, more flexibility and even one extra 1 phase output from the extra Multiplus. Is it possible and logical this way? Red colour is for new equipment. Is there anything else I should add (generator auto start for sure)?


Any ideas, suggestions or examples are welcome...


Karl Laasik asked
Juha Tuomala answered ·

5 Answers

Multiplus 12/3000/120 Overloads in a grid loss

Ok I will try to be as clear as I can.

I have 2 multiplus 12/3000/120 in a split phase config.

10 100ah Battle born lithium batteries with a shunt in two separate (5 qty ea) battery banks routed and fused to a single 1000amp terminal block

Battery Cabling is 4/0 Windy Nation and I will admit it is on the outer limits of length.

Inverter Cabling is 2/0 Windy Nation X2 from inverters to same 1000amp terminal blocks noted above.

AC units have softstarts but are already running at the time of the outage

The inverters will handle both AC units for many hours if I shut them down first then transfer power to the inverters and then turn the AC units back on. So they are absorbing the in rush from the compressors nicely just won't transfer it.

Problem: Inverter will not ups a 10-14 amp load on either or both inverters. If I am running say a 1000 watts or less there is no issue.

Observation: In VRM downloads I can't find anywhere the battery voltage dropped too low or the temps on the inverters at the time of the outage was 38C so according to specs should be able to handle 2200w each, no DC ripple, nothing I can see for the inverter to shut down.

Question 1: What else might cause this shut down. Could cabling being at the edge of acceptable lengths cause this but not show any indication of a cut off in VRM

rjoustra asked
Mike Dorsett commented ·

0 Answers

3 Phase MultiPlus with different phase loads

Is it possible to mix MultiPlus II inverters in 3 phase system? For example one 5kva model and two other 3kva? Or have 4 inverters - two sitting on phase 1 and other two dealing with phase 2 and 3?

Anyone build such system?

wojtek-m asked
marekp answered ·

3 Answers

Multiplus II 2x120 generator compatibility.

What is the condition that the Multiplus II 2x120 uses to determine its power flow as described in the Data sheet? Or whether the AC input is 120v or 120v/240v split phase?


In the case of the Multiplus II 2x120, when you connect the inverter in-between the automatic transfer switch and the RV panel the 120v/240v input connection works as intended and a 120v input connection also works as intended. Unfortunately it seems that the Multiplus does not pass through both lines from industry standard generators.


I believe the problem is that a lot of RV and off grid generators only output 120v. Most of them such as the Cummings Onan- 5.5HGJAB-6755L which is rated for 5500watts or 45+amps has two outputs. Each is 120v and outputs about 23amps. In most cases it is not possible to combine L1 and L2 out of the generator as the two lines are out of phase, not 180° out which would give you 240v but 120°. Meaning you can't combine the 2 lines to get the full 5500watts or 45+amps single phase to the Multiplus. Probably a cost savings thing on the part of the generator manufacturer as they can use the same components across multiple generator configurations. Either way this is common place in the industry here in the US.

So my question is, can the Multiplus II 2x120 be configured to detect this power type and passthrough both legs? If the Multiplus is actually detecting the phase and not just 240volts then there should be reason to believe Victron could remedy this with a firmware update. Correct? Also, if the voltage between L1 and L2 is 208v would that be an easier setting than the phase detection?

exmoso asked
rvsolarconnections answered ·

4 Answers

Two phase system changing to 1 phase in power outage

I have a very specific system in mind. I want to replace a tri-phase 240v connection to the house because it is 3 times as expensive as single phase power and have a backup power source. But there is an issue, there is a 2 phase 9kVA appliance in the house that is used sometimes. The 9kVA appliance is in two of the phases, and the whole house is in the other. My options are to move the house into the two phases provided by the victron and let them manage the incoming single phase grid somehow (which I think is not possible), or have two victrons run the 9kVA in an off grid type bi-phase system when grid power is functional, and switch one of them or the two of them when the grid goes down to power the house which would be in another circuit.

iabeck asked
shaneyake commented ·

1 Answer

MultiPlus ll and MultiPlus ll GX in parallel???


I have an ESS system with a Multiplus-ll 48/3000 / 35-32 on L1

and would like to set one more in parallel or on L2.

I have a 48/3000 / 35-32 GX

I want to hear if the two devices can run together or if a brand new one can run together with the old one I have.

They have the following number.

Multiplus-ll (it is running today with a Cerbo GX)

PN: PMP482305010


hw rev 12

Multiplus-ll GX (the one I would like to add)

PN: PMP482306000

SN: HQ201572K91

hw rev 05



jens-due asked
marekp answered ·

2 Answers

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