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split phase

Switch as group with split phase Multiplus 24/3000

I have two Multiplus inverters with a Venus GX setup in a split phase setup for a couple years now working well.
I have a solar inverter that has a backup single phase 2kW outlet I'd like to use if we have a long power outage.

Is it safe to just disable switch as group so I can use the backup single phase outlet? I've seen some posts on the forum saying there may be unexpected behavior but haven't found what that behavior would be.

Edit: Including drawing of setup

Eli Hunter asked
Eli Hunter answered ·

2 Answers

Unknown issue with split-phase (2x Quattro) - Overload

Hello everybody,

I have a split-phase system with the following components:

- 2x Quattro 48/3000-35

- Smart Solar 150/70

- Cerbo GX (with internet access)

- Lynx Shunt, Lynx Power In, Lynx Distributor

- Battery: 1x BYD LVL 15.4

I installed/wired the system myself around 3 months ago, and as of now I've been using it exclusively to power a 240v well pump (3/4 times /month). It's been great, everything worked absolutely fine up until a couple of weeks ago.

I noticed that inverter L1 was making some "random" noises. This is what I mean:

- the noise is similar to the noise it makes while inverting (when the pump is on, but it would normally be both L1 and L2 making the same noise...)

- it comes and suddenly goes, even if there is absolutely no charge whatsoever (like an "interference")

- it happens while L2 is silent and cold

- when it makes the noise, L1 is warm to the touch, just like when it's inverting but it isn't

I tried to update the firmware on both inverters (it's 497 now) and re-configured the split phase through the Quick Config Tool, but the problem persists. Consider that I got absolutely no errors from the VRM, nor I was able to find any error inside the Remote Console.

Today I tried to run a small washing machine with just L1 (120v) and it went Overload and cut the power. I tried with L2, but L1 would still go Overload and cut the power automatically.

(I know I should use the Autotrasformer, but I was just making some tests)

This is what I see inside the Alarm Logs (VRM):


As of now, the system is idle, meaning that the battery is 100% full and there are no charges, and L1 is still making this noise (sometimes!). Wiring stops right after the two inverters, nothing is actually connected to them apart from a breaker which is turned off.

I don't understand what it could be, considering that the system is almost brand new and it's been working perfectly for the past months.

These are the settings for BOTH inverters:







Any help would be appreciated! I can definitely grant access to the VRM portal.

I hope I made a stupid mistake inside the configurations, otherwise I'd be worried.

Thank you!

niccolaiddis asked
jeroen-kuijf answered ·

2 Answers

2x Multiplus II 5000/48 split phase 230v in 3 phase


I've been running a single Multiplus II 48/5000 for over a year. I live in Denmark and have 3 phases + Neutral in my home.

So i wanted to add a second Multiplus, for L2 to be able to produce more power, since i have 15 KwH on the roof.

Ive configured them as split phase with 120 degrees angle, however the inverters are just in "inverting" mode, and doesnt kick in to absorb, and feed in power from my battery. When i lool in VRM i can see that "Active AC input" is disconnected. I can also see that i have 230V on L1 and 233V on L2, and on AC-OUT L1 and AC-OUT L2 is at 230V 49,9 HZ.

I really cant seem to figure out, why Active AC input is dicsonnected.

Can someone help?

m1kkel asked

0 Answers

Single multiplusII with a 3 phases grid inverter


I would like to install a MultiPlus-II 48V 5000VA on L1 with a SMA Sunny tripower 8.0 grid inverter. The goal is to inject on the grid and to have batteries backup for essential load and night consumption.

Here would be the setup:

- Sunny Tripower 8.0 with L2 and L3 connected directly to the grid.

- MultiplusII connected on L1 between grid and Sunny Tripower.

- Meter ET340

- GX cerbo + screen.

- 300A 48v battery of pylontec 2000c

- MPPT 250/85 with 3000Wc of PV on the battery

- 8000Wc of PV on the Sunny tripower.

1. Will this setup work? whath do you think?

2. Is the factor 1:1 correct?

3. Is the phases imbalance acceptable?

Many thanks

loopoyu asked
loopoyu answered ·

2 Answers

Control 2 Quatros in Stacked Configuration

I have 2 Quatros in stacked configuration so I can get 120/240 2-phase output. I need to be able to control each Quatro individually so I can put one in Invert Only mode and the other in "On" mode so it will charge and pass through the A/C coming in.

I have a CerboGX as well as a RPi running node-red with the Victron nodes but can't seem to find a way to control one Quatro with out both of them changing.

Any way to do this?

Thanks in advance for any help!

ksaltman asked
ksaltman commented ·

3 Answers

Help with equipment 120v 30A In > 240v 30A Out > Split Phase Panel with 120/240v loads

I'm looking for some advice on how I would accomplish this. The idea I have is to use Multiplus to take the 120v shore power initially & step it up to 240 split phase with the AutoTransformer and then have the AutoTransformer feed a 120/240v split phase circuit break panel.

The loads are 240v 30a and the shore power in is 120v 30a North America use.

wildout asked
Kevin Windrem answered ·

5 Answers

Split-phase Quattro not accepting AC1 input

I have 2 x 48/5000 Quattros installed into an RV. Last night, I was running off of the inverter and this morning the system shut down due to low voltage (48v and change). The system has been running well for a few months until today.

My system is such that I have an external automatic transfer switch that switch between shore/campsite power and the generator. The generator is a single phase 5500 watt Onan generator.

I do not have "Switched As Group" enabled:



I am now plugged into a 50amp (120/240v campsite) and the system still isn't allowing power through. I've never been to this campground before by the Hughes Watchdog protection device and app aren't reporting problems.

The flashing LEDs on the L1 unit are "mains on" and "float". This combination doesn't seem to exist in the Victron Toolkit app. You can confirm the lights here. The L2 unit just flashes "mains on" as it seems it is waiting for L1 to make a decision.

Though I see a weird message in VE Config:


Adapting down to the 30amp connection (120v) doesn't help. I see the same "not in phase" message. And I still get the same "mains on" and "float" lights flashing. I've been able to adapt down to 30amp campsites in the past without issue.

I've attempted to switch the whole setup to parallel, but it makes a loud noise, immediately trips the system into overload, and my Hughes Watchdog reports an overcurrent issue on line 1. This is with essentially nothing on inside of the RV, so I'm very confused. And, I've set the input current limit down to 10 amps (as seen in the VictronConnect screenshot below).

I've measured voltage at the AC1 input on each inverter and it reads in the 120v range. The VictronConnect app does, as well:


Here's my system diagram: https://i.imgur.com/BLybuWG.png

Here's my Rec BMS setup: https://i.imgur.com/4zm0l04.png

learntorv asked

0 Answers

Quattro 48/5000 showing State: Blocked and not allowing AC power ni/through

I have 2 x 48/5000 Quattros that have been working for a few months now in an RV. Last night, I was running the system using the inverter and this morning, I got cut off due to low battery voltage. Expected, but not ideal. When I started the generator, it wouldn't allow AC power to pass-thru the inverters or to charge the batteries until I switched out of split phase and into parallel mode. (The generators output single phase 120v but have worked in the past with the inverter.)

Now that I'm plugged into shore power at a campsite this evening, I'm having issues getting the inverters to pass-thru power or to charge the batteries. I've plugged into 50amp (120/240v split phase) and into 30amp (120v single phase). I've tried the inverters in split-phase, parallel, and a whole mess of combinations. They all end in me either tripping the inverter's overload (when on parallel) or just not allowing power to come in.

Supporting images/videos:


learntorv asked
learntorv answered ·

1 Answer

2* Multiplus II as ESS in Germany (with 2 batteries) - design question

Hi there,

I want to build an ESS consisting of 2 Multiplus 2 (48V 5000) with two 280Ah batteries - so my main goal is to keep the meter at zero, not so much to gain independance from the grid or to create an UPS for my loads at home.

Currently I am struggeling on "how to design" this ESS correctly. My understanding is that there are 2 options (due toi "Schieflast" in Germany paralleling is out of question.

  1. Connect the 2 MP2 as a 3phase system (obviously only creating a 2/3 part of a 3 phase system on L1 and L2). The systems will share both batteries via an appropriate busbar, one Cerbo GX required.
  2. Have two completely separated MP2 installations - one on L1, one on L2 for example. This would requried a Cerbo GX for each. But how will those system align on the grid setpoint?

Option 2 seems easier to wire, with the problem to get the meter info to both Cerbo GX, but I guess using the mqtt-dbus approach that should be manageable. Option 1 would be wuite ok for me, if this is supported by Victron.

Happy to hear some suggestions on this one.

Thomas Büschgens asked
Kaspars commented ·

1 Answer

Getting 120v from a 240v Quattro 48/15000/210 - Is the Autotranformer Necessary?


I have a simple questions regarding the need for an autotranformer to achieve 120v from a 240v Quattro 48/15000/210 . Is the autotranformer necessary?

Can I not use a bonded neutral and a hot (L1 or L2) to achieve my 120V?

Or, will that create an imbalance in the Multiplus?

This is completely off grid, with not interaction with the grid whatsoever.

I would appreciate clarity on the matter.

Thank you

aventurateutonic asked
aventurateutonic edited ·

3 Answers

Dual Multiplus 12/3000 in Split Phase Running on Single Phase

Hi folks,

I'm new to the forum but have been looking for an answer. I have two Multiplus 12/3000 inverters with a Venus GX (and additional Victron solar items as well) in a motorhome. These were all purchased in last 90 days or so, so fairly new hardware. The motorhome is wired in split phase and everything works 100% of the time when i'm on a 50amp standard USA RV service. My setup also cuts over to my QD1000 generator flawlessly and everything works fine.

My issue is when i'm plugged into a 30amp single phase plug. When I am, I understand normal operation "should" be that my master inverter will invert and charge the battery and my slave inverter will simply invert. This is a Victron limitation on single phase power as i understand it which is fine. My question is. When i'm plugged into a single phase 30amp plug, neither the master nor slave inverter will recognize the AC input. The input shows in the Venus panel as there on both legs (single phase on both legs because of the 50a to 30a dogbone adapter that pairs the single phase 120v to both legs) but the units will not initiate a charge, its basically like i never plugged anything in at all. See attached screenshot. Any advice on what setting may be causing this to occur? I'm fine with only one inverter charging, i just need to understand why thats not happening..



Any helps or advise would be greatly appreciated.

epm96 asked
bludgrumber edited ·

3 Answers

Multiplus in splitphase troubleshooting.

Need some troubleshooting help.

12v system. I have 2 - 3k Multiplus in split phase. Going to 6 100ah batteries.

Multipluses are wired to lynx distributor with 200amp MEGA fuses.

Something happened at 11:00am today. Rig sitting in garage so no solar coming through system. Started getting warning emails from Cerbo that “devices not detected”. Our batteries started a slow discharge at this time. Has been a steady 8-12 amp draw on them all day. Using multimeter found that the master multiplus mega fuse was blown. Replaced the fuse. multiplus is viewable on the cerbo but we are still discharging. When we unplug from shore power the rig goes dead.

Any thoughts or direction we should go?


keevs5 asked
Alexandra commented ·

1 Answer

Autotrasformer for US split phase and 15 kva Quattro

I would like to connect 2 Quattro 15 kva in parallel for an output of 24 kW. I would also like to connect that output to the 100 amp Autotransformer to obtain a 120-N-120 split phase (USA). I have seen the circuit diagram describing a similar connection with 1 Quattro, but I have not been able to confirm if you can do with two inverters in parallel. Thanks!

gprado asked
charlie commented ·

3 Answers

3-phase to 1-phase quatro 15kW

Hello. I have a 3-phase network at home. If I wanted to connect all phases to one quatro 15kW, how would it be combined? In the event of a quatra failure, the sleeping phase would be disconnected to the three-phase network. I do not use any three-phase equipment in the house. One powerful phase is enough for me.


mio23 asked
mio23 answered ·

3 Answers

Quatro 15kW or 3 x Quatro 5kW?

Hello. I have a dilemma. My house receives 3 phase electricity from the supplier. I want to replace this electricity with my own solar energy as master energy. Please, can someone tell me if it is good to have 3 x quatro 5kW or one powerful quatro 15kW. I'm afraid that 3 quatros won't be as noisy as one quatro. But won't one quatro 15kW have a big loss or consumption for itself like 3 quatros? In the house, I would probably merge 3 phases into one via a contactor. If the quatro falls out, it divides the phases back into 3 phases. Is this a stupid solution?

mio23 asked
kevgermany commented ·

2 Answers

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