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3 phase

ESS: Basic Understanding for Factor 1.0 rule and 3 Phase PV Inverter


I couldn't find the answer to my question in the forum, so I'd like to ask it here:

I'm talking about an ESS Scenario where I can use Phase 1 as a Backup if the grid fails. (One Multiplus-II between Grid and Phase-1 Loads).

I have a Fronius Symo 5.0 and a Multiplus-II 3000. So I'd like to install 1 phase of my fronius PV on AC-OUT just in case the Grid fails. But as far as I have understood I cannot do that because the PV Inverter delivers 5KW and the Multiplus-II can only handle 3 KW.

But what I do not understand is the following: How does the PV Inverter split the energy delivered from the PV Modules on the 3 phases? And what's the maximum load that's deliverd on one phase? Let's say phase 1 is on AC OUT of the Multi, phase 2 and 3 are on AC In side. So in case of a grid failure: would the PV Inverter put the entire power on phase 1?

So let's say I add a 2nd Multiplus-II. Then Factor 1.0 rule would be OK. Phase 1 and 2 of the PV Inverter would be on AC OUT, Phase 3 on AC IN side. How would the power be deliverd from the PV Inverter in case of a grid failure? Would it deliver all power on Phase 1 and 2?



florianro asked
Rob Duthie edited ·

3 Answers

3 phase system multiplus


I have the following:

3x Multiplus 3000/24/70

1x Skylla 50A Charger

6 x 12V 50AH AGM battery

I'm planning on using this to create a 3 phase system by turning the batteries into 3 banks of 24V.

Apparently this equipment was used to create the same system before but I'm a little confused how to hook this all up (I assume the configuration should be ok although I would need to figure the phase rotation). I presume I'm hooking the 2 batteries in each ban in series and then they connect to the battery connections of the inverters and then I know I need to daisy chain the invertors with Cat5 cables but do I need an external switch or will they only start outputting if the panel switches are all on? Finally, I assume I take the lives of each inverter for the relevant phases but what about the neutral? is it best to feed these into a bus bar and tap my neutral from there?

Also, how does the charger figure in this setup (charger being fed by 220V AC from the grid No solar stuff involved.

simonwait asked
Jwfrary commented ·

0 Answers

MultiPlus Compact 12/1600/70 ant two MultiPlus 12/1600/70 to 3 phase grid

Can I connect MultiPlus Compact 12/1600/70 ant two MultiPlus 12/1600/70 to 3 phase grid?

DmitrII asked

0 Answers

system works like disabled phase compensation although, it is enabled, using 3xMultiplus2 on 3 different phases in ESS grid system, configured to switch as a group, each inverter on a different phase in 3 phase configuration

i installed 3x MP2 3000VA /48V. Updated Firmware to 2629474. made ve quick config, setted all settings. made the ess assistant in each MP. Now i try everything but the whole system acts like phase compensation is disabled although it is enabled. each inverter does only deliver so much power as required on the specific phase according to the grid meter. No idea why the compensation setting in the venus gx is not working. Please help!!

AC L1,L2,L3 is connected to MPNr.1-ACIN, MPNr2-ACIN, MPNr3-ACIN. The system is useless. If the electric car is plugged in on one phase with 7kW it only delivers max. 2.4kW from one inverter, if no other loads are switched on. If someone cooks on L2, i only get 2.4kW from the inverter on Nr.2.

I read all installation manuals, the training video on the Victron professional side, there is no hint what is wrong, looks like a software bug on the Venus gx!



gnagflow asked
gnagflow commented ·

3 Answers

3-phase Multiplus II system, am i thinking right?



i am planning a solarsystem whit 3x VE MultiPlus-II 48/3000/35-32 ( se more in picture) for a 3-phase system.

I have made a simple wiring diagram over how i´m planning to set it up, am i thinking right?

- I want a 3-phase, for example the heating system needs 3-phase to work.

- UPS-funktion of the whole household

- i want to use as much solar energy i can for myself, more optimised for winter then summer.

- not designing the system to be optimised to sell as much power i can. not selling at ALL right now.

- want to use ESS, have lead-acid batties right now, planning to upgrade to lithium a.s.a.p.

- yes a electrician will connect it all.

I was just hoping a "victron-guru" could take a look and see if i´m totaly off or just maybe close to actually thinking right :-)

// Jocke

Jocke_h asked
Jocke_h answered ·

3 Answers

Quattro 48/1000: combining 1 battery bank to 4 quattro's: 3Phase + 1 Single phase

Dear all

Can I expand an existing 3phase Quattro system with 3 quattros 48/10000 and 1 battery bank with an extra single quattro 48/10000 for an extra single phase load connected to the same battery bank.

Thanks for the feedback


FandM asked
Jwfrary answered ·

2 Answers

3 Phase Supply, 3 Phase PV GT Inverter but Single Phase MultiPlus II - TWO Questions:

Hi Expert Community,

I have a site planning a 3 Phase Fronius but wanting to ESS optimise and Backup on ONE Phase only using a MultiPlus II.

Question 1: Can I use a 3 phase Victron Energy Meter (ET340) on the Grid Supply to control the Single Phase MultiPlus (obviously Via a GX device) ???

Question 2: How will the DATA of the Fronius be displayed and logged on the GX and VRM?

The customer wants all the data to be visible and accurate on the VRM Portal (of course!) but I am not sure how the Load will be calculated across the three phases - especially the backup/ESS phase.

Ben Stanton asked
stxShadow edited ·

1 Answer

Unknown battery draw down


My recently installed system has a colour control which reports (contradictory) ve.bus battery state information from the Mutli's and a 3ph PV inverter in off grid configuration. With All output MCCB switched off, there is a constant +-100W (2A) draw indicated in the battery symbol in addition to the L1-L3 standby load. This discrepency is also not included in VRM portal output.

Going into winter this unplanned loss will significantly affect the battery SoC. Is this indeed an undocumented standby consumption within 3ph configuration of the Victron inverters, or is the in built BMV reporting incorrect info?

SoC at dawn reads: <60%

Lead acid capacity:9.8Kwh

Reported night time load: 2Kwh



rnieckau asked
Daniël Boekel (Victron Energy Staff) commented ·

3 Answers

Help with Fronius Symo 15kW 3-phase and Victron MultiPlus II configuration


I'm planning a new solar installation on a new house build and was hoping someone could please help me determine the best way to plan and configure it. I'm aware of the 1 factor rule but I'm not sure how it applies to 3-phase installations - if I plan to install a 3-phase Fronius Symo 15kW inverter, does that mean I could install 3x Victron MultiPlus II 5000VA units connected to each phase?

This is the configuration I thought would work best but I'd really appreciate help on whether this configuration is valid and if anyone has thoughts on this design?

Some questions:

  1. Can I use the Fronius smart meter to monitor consumption or would I be better using the Victron smart meter?
  2. Given the somewhat disparate use of inverter vendors, is it possible to view and monitor the system using one portal/monitoring system?
  3. Is there a bypass on the Victron MultiPlus units in the case where the batteries are charged so there's no 'processing' or loss as the electricity passes from the Fronius Inverter to the home's loads?

Many thanks in advance.


gyrex asked
gyrex commented ·

2 Answers

3 Phase Grid Tied Battery storage system with Generator Back Up - Please Help

Hi there,

I am quite new to Victron but have been using SMA Sunny Island. I have heard great things about Victron. I have the below scenario.

The panels will be connected to a 3-phase grid-tied solar -PV inverter to the main-distribution board at the house. To this distribution board we will connect BYD LV batteries using a 3 Phase battery inverter. This inverter will operate in self-consumption mode when grid is available.

When the grid goes off the line, the system will back up all 3 phases till the batteries reach their maximum allowed discharge level.

The system will then start a suitable generator automatically (to be provided by you) and will charge the batteries to a pre-set charge level before turning it off. This cycle will continue till the next day, when the Solar panels starts producing power or until the grid comes back on.

Do i use the Multi-plus 2 or the Quattro to achieve the above solution ?

Many thanks


jayesh asked
iRomeo commented ·

1 Answer

3 Single phase inverter in 3 phase grid?

Hi everyone,

Right now i'm fully off-grid, using 8kva Fronius and 10kwa Victron.

Potentially, next year, 3 phase grid power might be available. And I have the opportunity to swap my Fronius, for 3 units of 3kva each, but they are Primos, hence single-phase.

I currently have 30 panels installed, and tinking of splitting them into 3 rows, thus having 3 identical 2750w panels with 3 identical 3kw Fronius inverters.

Would it be possible to patch each of them to the 3 phases of the grid?

My Victron and battery set-up would only serve as UPS for one of the phases with critical loads.


iRomeo asked
iRomeo commented ·

1 Answer

3 phase CHP for charge & Quattro 48/10000 single phase in a single off-grid config


in order to integrate a new CHP machine/generator (2kw on the electrical side) i need a 3 phase on that side to charge BYD lvl batteries - for that i would like to deploy a small 3 phase 'sub-grid' just with the CHP generator connected on the AC side based on 3 x MultiPlus 48/800. On the 'consumer' side i thought about a single phase Quattro 48/10000 box. In addition a few MPPTs charging the batteries from the PV side. That raised the question if a a venus system (i.e. Cerbo) can manage all of that in a consistent way ?

best regards,


martghh asked

0 Answers

3 Phase extension for a microgrid - MultiPlus or MultiPlus II


going forward building a 3-phase microgrid (island) configuration, i looked at the specs of the (still available) MultiPlus 48/5000/70 and the new MultiPlus II 48/5000/70. This shows only a 10% difference in max. power (10 vs 9 kW). Looking inside, the MultiPlus II has a higher integration but a single and smaller transformer indicating less support for high peak currents. Are the other differences not documented leading one or the other better suited for a microgrid config ?

best regards,


martghh asked

0 Answers

Multi 3 phase question about VE Bus Configurator

If anyone may know, in the VE Bus configurator software for 3phase Multi systems, is it necessary to select, as well as 3ph via the 3phase button on the software, 3 AC inputs? To reflect the three phases L1, L2, L3 coming in? It is a bit unclear...in the help file...


Craig Myatt asked
Craig Myatt edited ·

1 Answer

1p to 3p configuration?

Is it possible to set up a 3p configuration, where only one of the Quattros/Multis has GRID (because the grid is 1p)?

Ideally within an ESS system.

PetaJoule asked
Daniël Boekel (Victron Energy Staff) answered ·

2 Answers

Loss of mains on one phase of a 3 phase system

Hi all,

I have a 3 phase system using 3 x MultiPlus II.
I had loss of mains on one phase due to maintenance on the grid.

The hybrid system didn’t kick in. I had to turn off mains on three phases to simulate loss of mains for the hybrid system to work

Is there a setting to allow the system to run the back up loads when only one phase losers mains.

Danlowey asked
Daniël Boekel (Victron Energy Staff) answered ·

3 Answers

PV Inverter Assistant - unbalanced PV


In the PV Inverter Assistant it says 'Each phase must have the same solar power installed'

So what happens if it is not balanced? If the 1:1 rule is adhered to on each phase will it be ok?


Stevo07 asked
Stevo07 commented ·

0 Answers

3 phase single phase grid

Have a possible system to install

Client had a single phase AC grid supply

Is currently having to use a 3 phase generator for his 3 phase equipment means

Wanting to install a 3 phase Quattro set up With 3 phase fronuis SYMO to make make a micro grid

I know we can use the 3 phase generator for supplement the charging that the solar is falling short of

my question is can the single phase grid supply usable for supplementary charging with the 3 phase Quattro setup

Answering the question my self I would say no

Tho I think it may be usable if a single to 3 phase converter is used ???

anyone have any thoughts on this ?


mikeb asked
Daniël Boekel (Victron Energy Staff) answered ·

1 Answer

3-phase Star supply to 3-phase Delta load



In the Phoenix inverter manual I could read that the Phoenix is not suitable for delta configuration when used in 3 phase.

I am questioning the possibility to feed a 3-phase delta load from a 3-phase star source made out of 3 Phoenix inverters ?

Is that possible or there are any concerns ?

Kindly advise.

Thank you

Mark Moussa asked
Mark Moussa commented ·

1 Answer

3-phase 230V system


Is it possible to configure a low voltage 3-ph off grid system using the Quattros? That is a 230V 3-ph IT network like in Norway.


Stevo07 asked
Stevo07 commented ·

1 Answer

Quattro Neutrals?

I was watching Guy's 3-phase Quattro installationvideo on Victron Professional and had a question regarding the Neutrals on ACin and ACout.

Does these two Neutrals have to be separated? I know the Neutrals on ACout has to be linked in a 3-phase setup, but is it possible to link also ACin Neutrals to the same busbar as the Neutrals of ACout?

Forexample in a TN-C grid with a combined PEN, PE and N are linked in the switchboard. So ACin would then have PE and N linked already (at the switchboard).
If there is no RCD on the ACout from the quattros, could the Neutral from ACout on the quattro go to the same busbar as PE and N are linked to in the switchboard?

I know best practice is to install a RCD and have Neutral from ACout go to an isolated Neutral busbar in the switchboard. I was just curiouse on if the quattro NEED to separate ACin Neutral from ACout Neutral or if they can operate together on the same busbar.

Also, what dimension is the chassi ground on Quattro 5K 230V? M6 or M8?

Kind Regards


ehsab asked
ehsab commented ·

1 Answer

#10 Alarm system time sync error , #1 device switched off random reboots

For last couple of months my system ( 3 x 5 KVA Quattors in 3 phase with BYD 10 KWH) randomly resets ( all the quartos go offline and come back on)

#10 Alarm system time sync error, #1 device switched off commonly seen.

Initially, I Suspected network cabling so replaced with CAT 7 high-quality cables and cleaned the network sockets with contact cleaning fluid

Also, checked if all DC connections are tight ( they are )

There seems to be no pattern to these switch offs ( observed at 2 am in the night and also during afternoon or evenings ) -

The system works fine for a couple of weeks and in one day I could face one or more restarts with associated error logs

All firmwares are the latest except Quatro which are on V430 ( latest is 464 i believe)


1- Is there a detailed log somewhere indicating which unit is causing the shutdown

2. Should I upgrade quattro firmsware to rule out any other issues

3. Is this the issue of any external EMF affecting the network cabling ( they run parallel to the power cables - not in my opinion as CAT 7 are each pair individually shielded )



Class F channel and Category 7 cable are backward compatible with Class D/Category 5e and Class E/Category 6. Class F features even stricter specifications for crosstalk and system noise than Class E. To achieve this, shielding was added for individual wire pairs and the cable as a whole. Unshielded cables rely on the quality of the twists to protect from EMI. This involves a tight twist and carefully controlled design. Cables with individual shielding per pair such as category 7 rely mostly on the shield and therefore have pairs with longer twists.



Anil Ghatikar asked
Anil Ghatikar answered ·

2 Answers

3phase system with a single Quattro and two PV inverters

Hi all

I need some advice on the following design.

A 3 phase system with a Quattro plus DC coupled PV and battery on one phase. Then added is two PV inverters on the other 2 phases. The PV inverters aren't fully compatible with Victron so Energy Meters will be needed to read data to the gx device.

My question is on Meters, do I need a three phase meter in the main supply and an additional 3 phase meter on the PV inverters. Or can I use a 3 phase meter on the PV inverters and a single phase meter on the Quattro phase.

My goal is to see all the PV and consumption data of both the PV inverters and Quattro on the gx device for all three phases.

Bosvark asked
abrahamsolar answered ·

1 Answer

Ac coupling and three phase


I have a 3 phase of grid system with a 3 phase generator as backup. The system has 3x5000 multiplus, 1x 70/150 mppt, 920ah gel battery bank, color gx and bvm. We need more power and I was wondering what is the best way forward

The new solar array will have to be placed around 80m away from the current system. At this point I have the option to either run DC power back to the system and install more mppts in parallel or I can tie in to the mini grid here.

My question what will be the best option? I have a couple of options.

1) Do I dig a trench and send 150 V DC power back to the system and intall 2 or 3 more mppts

2) If I install a 3 phase grid tie inverter 80m away from the system do I need to communicate with it? Do I need to install CTs that needs to communicate with the PV inverter? Do I need to install other communication between the system and the PV inverter? What inverter do I install? Make and max size

3) Do I use 3 single phase PV inverters in the same setup above? 3x5kva?

4) Do I install a 3 phase PV (or three single phase) inverter with the system and run high voltage DC from the solar array to the system?

Will the system integrate with the generator without damage to the generator, loads inverters?

Any help would be appreciated



Wilhelm1987 asked
Anita answered ·

3 Answers

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!


Anita asked
Anita commented ·

3 Answers

Ve Bus error 3 and 25

A perfectly working 3 Phase Quattro ( 5 KVA) system has started switching off suddenly on following errors

Ve Bus error 3 - Not all, or more than, the expected devices were found in the system


VE Bus error 25 - Firmware incompatibility


On Phase, A/L1 only float LED flashing ( could not find the meaning in Victron Toolkit )

On Phase B/L2 and C/L3 LED matching to Ve bus error 3 ( absorption and inverter on LED flashing)

A switch off and switch on of all the three units seems to resolve the error for a few hours

Is it possibel that the error is generated when only L1 phase is not available from Grid ? but the Ziehl islanding should also detect that error

Following checked

A. Any changes ?- System is operation since last year - no changes in hardware and only Smart solar /venus firmware upgrades

B firmware

All smart solar ( 2 no.) are on V 1.42

All three quattro's are on V430 ( device 2657)

Venus is on 2.33

C. Ve bus cabling - seems to be firm and no issues detected - changed the sockets just to be sure on Phase A/L1

D. AC and DC cabling - no fault detected on a visual inspection and AC/DC voltage checks ok on all terminals

Video - https://youtu.be/lFF-Fo6UvG4



Anil Ghatikar asked
Anil Ghatikar edited ·

2 Answers

Please check my future setup


I need modification existing boat circuit (without replace charger).

I need next:

if voltage from generator is low - MultiPlus switch to inverter mode

I must can switch off all MultiPlus from computer (connected to Venus GX)

OlegPowerC asked
Rob Fijn answered ·

3 Answers

Fronius Symo not ramping up to meet house demand.

My Fronius Symo 15 has 18kw of solar panels installed. Multi plus 48/5000/70 x 3 in 3 phase config. Even though Fronius has 15kw available, the multiplus always ramps Fronius down considerably & doesn't ramp up to meet house demand but instead takes it out of the charge so the charge is reduced. Why isn't Fronius ramping up?

Daren Connor asked
Daren Connor commented ·

1 Answer

Scalable system

I'm planning to build three vans with the same system on each.

The system on each van will be:

- 24v Battery

- Multiplus / Quattro 24/3000

- And maybe, an mppt, a BMV and a Venus GX

My question is, there is a way so I could connect and reconfigure the settings of the systems to work together so 3 multis on single phase o 3 multis in three phase?

My big concern is about monitoring the batteries.

If I use the battery monitor on each multiplus they can run each one on its battery or they have to run both with the same battery and use a BMV?

There is a way so each multiplus is working with its battery but connected with the other multiplus? Each multiplus can take care of its own battery?

I asume that this is not possible with a Venus and three BMV or three Venus connected together, sharing data, no?


bivaccamper asked
bivaccamper answered ·

2 Answers

3 phase Quattro 48/10000 problem with dedicated ignore AC

Hello, we have a 3 phase system with Quattro 48/10000.
We have program the inverters with virtual switch, dedicated ignore AC input.

The load parameters set to each inverter are: do not ignore AC input when the loads are higher than 7000W for 5 seconds.
This parameter works only for L1. When the loads are higher than 7000W on L2 or L3 the system does not switch to AC input.

Please advise as soon as possible!

Kind regards.

Alexis Kalogerakis asked
JohannK commented ·

1 Answer

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