VE.Bus Image


VE.Bus Error: VE.Bus Error 18: AC Overvoltage on the output of a slave has occurred while already switched off

We have set up two Multis 48/3000/16/35 in paralel w BYD premium battery W BYD BMS 15,4kWh/48V AC coupled w Fronius Primo 8,2, w limited AC power output to 4800W PV field is 9000W but w limited AC output on Fronius Primo.. All firmware is up to date, cabels same lenght, Fronius is set as MG50, and we have Maste and slave unit. Also we have 3 pv panels 300W as back up on Smart MPPT charger connected to Cerbo.

It is off grid system set up at island in Adriatic, we have system up and running but we have every day alarms from 1 to 10 ( VE.Bus Error: VE.Bus Error 18: AC Overvoltage on the output of a slave has occurred while already switched off) . The system is up on VRM, but we cannot find the answer what to do.

Load is at the moment up to a 100W. We have Cerbo GX w touch screen and it is operational at VRM.

Zdravko Vugrinec asked
iwan answered ·

2 Answers

VE.Bus Error 10: System time synchronisation problem occurred

Using 2 Quattro 120V/48/3000W in Split mode connected to a CCGX. System also includes MG Energy Lynx BMS, 3xMPPT.

Quattro had no Assistant installed.

System was not conneted to any Grid source. used as Off grid mode only. using a generator to recharge batteries only twice in the last 6 months.

Wanted to upgrade system

Now Quattro connected on

- AC1 to Split phase power from Bahamas power.

- AC2 now connected to a generator input.

- Upgraded Quattro from 463 to 482

- Upgraded CCGX from 2.63 to 2.66

- added VS Ignore Ac Input to both units.

As long as i do not connect the quattro to the CCGX, the Quattro operates. Within 30sec of plugging the CCGX, get Error #10 : System time synchronization problem occurred

Error also happens if the Quattro are set to Charge only.

Lights on the master go away, lights on the Slave show loss of syncronization. Seems like the Master quattro is reseting. 30 seconds or so later error goes away only to reoccur 30 second later.

Try 3 different set of cable. They all work if only connecting the 2 Quattro. Error only occur when you plug the CCGX.

Try 2 different CCGX same

Try to move ports around same

Used contact cleaner on VE. Bus ports

Checked Ground voltage from CCGX 0 volt source (BMS voltage regulated output) to Quattro ground. All good.

Checked for Battery fuse: Good

Checked tight Connection: Good.

Any suggestion would be welcome.

jmarc asked
enersol commented ·

1 Answer

New 3Phasesystem Multiplus 2, Error 3 (English)

A new installation with Multiplus 2, cerbo and MPPT getting always error 3

One of the multis came with an older firmeware, so I updated it with the “Flash-Programm”, after I connected all 3 multis with the udp cable and mk3 usb adapter to the laptop and configured the 3 phase system and did all the settings in the configuration tool.

Connected the 3 multis to the cerbo and did the update off all firmeware over the VRM Portal successfully, so for me means the bus is ok.

The endtermination are plugged in and they also have 120 Ohm. Checked the UDP cable with a networktester, also ok.

AC input and Batterie input also OK.

Connectet 4 old carbatteries in Serie for testing , the BYD is not delivered yet.

I also startet again from beginning, flash the software new to all multis with the “flash-tool” and configure again, but always the same.

Hope someone can help me.





gangl79 asked
Alexandra commented ·

4 Answers

On the Skylla IP44, what is parameter 31 ("BMS present") for?

Why do you need this parameter?

It implies that one can connect the Skylla IP44 to a VE.bus BMS, but is that correct?

If possible, how would you connect it as the Skylla IP44 doesn't have VE.Bus connections and the BMS doesn't have any VE.Can connections?

s-v-simbora asked
s-v-simbora answered ·

1 Answer

VE.BUS Connection - Venus GX and VE.Bus BMS

The VE.BUS BMS manual has a warning stating; "A Digital Multi Control panel must be connected to the VE.Bus BMS. Do not connect a Digital Multi Control panel directly to a Multi or Quattro (signals from the control panel may be in conflict with signals from the VE.Bus BMS)."

I am using a Venus GX connected to "remote panel" port of my VE.Bus BMS. This setup works but I would prefer to connect the Venus GX directly to one of the two VE.Bus ports in my MultiPlus so that the Remote Panel port is accessible for connecting to my MAC which running Victron Connect.

While the warning (highlighted above) doesn't mention Venus GX, I was hesitating to connect the Venus GX directly to the MultiPlus.

Can anyone with a similar system using the VE.Bus BMS share how they have wired the VE.Bus connection for the Venus GX?


abegweit asked

0 Answers

Multiplus Compact 12/1600VA doesn't work with ve.bus smart dongle

I bought a Multiplus Compact 12V/1600VA and the matching ve.bus smart dongle in October 2021. Unfortunately, the Multiplus that is connected to the dongle with a CAT6 cable is still not recognised in the Victron Connect app on my iPhone.

Temperature and voltage are displayed.

I don't have a Cerbo and have waited longer than 30 seconds. MP is switched on, of course.

I have tried both connections in the MP and also a different cable. I have also had switches 1 on and 2 off on the switch board.

Now the reason could be that the firmware on the MP is too low, but since the device is from 10/21, it should also fit.

What else could be the cause?

ericflex asked
ericflex answered ·

2 Answers

Can anyone help? ESS still not working.

I have had my Victron Multiplus 2 GX 5kVa unit for a week now of which it has only worked correctly for 2 days out of 7. When it did work correctly, it was perfect. ESS at its best but after 2 days I identified I needed to make a change to the settings in the config file. When i went to do so, the option to download the config file was missing form the VRM portal. Reading the forum and Victron self help guides, it appeared I needed a firmware update. I followed the instructions for the update to the point as best I could assuming all was well only to find out ESS had stopped working after I had finished the update. I have tried everything!. I have re-uploaded the config fil from EV Configure 3 several times, I have checked the settings in the remote console, I have previous posted on the Victron Community forum trying to resolve this issue which has given me other things to try but still no luck getting the inverter to invert automatically.


I have been directed to load my 'rvms' file into the VE Bus Configurator but I have no RVMS file and no one seems able to tell me where to find the file.

The company I purchased the unit from don't have a clue, they only know how to sell products so they are a waste of time. There is no apparent information on the Victron website on how to resole this specific issue.

List of relevant setting / info from within VRM Remote Portal

  • Multiplus-II 48/5000 / 70-50 / Switch / On
  • Product ID 2623 Firmware Version 496
  • VRM instance 275
  • VE Bus version 2623496
  • Mk2 version 1170212
  • Setting / Firmware / Firmware Version v2.85
  • Setting / Remote Console / Enable on VRM / 'On'
  • Setting / System setup / AC Input 1 / 'Grid'
  • Setting / VRM online portal / VRM two-way communication / 'ON'
  • Setting / ESS . Mode / Optimized (with batterylife)



List of relevant setting / info from within VE Configure 3 (Then uploaded via VRM)

  • General / External Current Sensor - tick
  • General / Enable Battery monitor - tick
  • General / shore input limit / 50A
  • General / Overruled by remote - unticked
  • Inverter / output voltage - 230v
  • Inverter / shutdown on SOC - tick + SOC shutdown 20%, low restart 50%
  • Charger / Enable charger - tick
  • VS / Do not use VS - tick
  • Assistants / ESS



Link to video showing settings used in the above

Again, any help in resolving this issue would be greatly appreciated. I thought the firmware update had failed as ESS stopped working after the firmware update but with the advice recieved and the information available on the Victron website, it now appears to be something different. Is there is inverter limiter hidden somewhere in a setting. Comments and suggestions please. I'd be happy to share my screen with some one via Teams or Zoom.

Jason - UK asked
Rob Duthie commented ·

3 Answers

Lynx Shunt ve.can + Phoenix Inverter ve.bus + CCGX + what else?

My new lynx shunt with ve.can ports is sitting a foot away from my phoenix inverters with their ve.bus ports and quite obviously they cannot communicate with each other. The inverters are connected to a CCGX panel about 50 feet away obviously via ve.bus, and the CCGX's ve.can port is connected to a N2K adatper to feed my main data backbone. I would rather not pull another 50 feet of cable through this boat to bring the shunt's ve.can port up to the CCGX. What are some viable alternatives? The goal is to see the shunt on the CCGX and for the shunt data, along with (already working) inverter data to be forwarded to the N2K bus through the adapter from ve.can

Add a Venus GX (or Cerbo GX) near the inverters and shunt and connect both ve.can and ve.bus to the Venus - will the Venus/Cerbo forward all the data between both networks so the CCGX will see it all?

Add another ve.can-N2K adapter on the shunt's ve.can port - will the CCGX see the shunt data on N2K and bring it in as ve.can?

Save up a lot of money, buy the entire Victron company outright, and put them to work making all their products network compatible without the use of a different unique adapter for every device?



Chris Barber asked

0 Answers

VE.Bus BMS with Cerbo

Can i interface a VE.Bus BMS directly with a Cerbo? I had assumed that a Multiplus was required but i've been looking at the Multiplus 12V 500VA which only has a single VE.Bus BMS port with a comment about using an RJ45 splitter to interface with a GX device. This would suggest to me that the BMS could talk directly to the Cerbo

chrisryan43 asked
chrisryan43 commented ·

1 Answer

VE.Bus BMS and MultiPlus / Cerbo combination

I have wanted to be able to control the Multiplus via the Cerbo, but the VE.Bus BMS and VE.Bus BMS Assistant on the Multiplus block the Cerbo from changing the invert state between On / Off / Invert Only / Charge Only.

Having done some testing I have reverted to the 2-Wire BMS assistant on the Multiplus and wired the VE.Bus BMS Charge Disconnect to the Aux 1 port and Pre-Alarm to Aux 2, using an Inverting remote on-off cable. I am now able to change the status of the Multiplus from within the Cerbo Screens. The Cerbo correctly shows the VE.Bus BMS status through the relevant MultiPlus screen. Both disconnected at the moment.


I also had a VE.Bus Smart Dongle and found I could modify the status of the Multiplus via my phone as well. When status changed the Cerbo reflected that changed status. So I have a system working as I would like, but not using any functionality of the VE.Bus. I guess I could have achieved the same thing using the smallBMS with pre-alarm.

What I was wondering is if anyone can advise what functionality I might have lost by disconnecting the VE.Bus BMS from the VE.Bus?

I have noticed during my testing today that there is no Alarm or Error that is logged when the VE.Bus BMS signals load or charge disconnect, simulated by disconnecting the signal. The Cerbo clearly isn't triggering on the change of the Multiplus VE.Bus BMS status. I am not sure if it ever did alarm/alert when the VE.Bus BMS was connected via the VE.Bus port to know if I lost functionality. I do know a few weeks back I had a VE.Bus BMS Charge disconnect event and never saw anything on the Cerbo.

Hope people find this useful and it would be good to understand what functionality has been lost by taking this approach and not have the VE.Bus BMS communicating on the bus.

bathnm asked
lavignedavid answered ·

1 Answer

VE Bus 276 - low battery alarm when turning on Multiplus II

Some background on my system: I have a 1995 Casita RV with the following power system:

1780 watt Canadian Solar bifacial solar array powering the following Victron components:

4x 12 volt LiFePo4 smart batteries,

1x Lynx Smart BMS,

2x Lynx Distributors,

1x Multiplus II 12V/3000 watt Inverter,

2x Bluesolar 150/70 Charge Controllers,

1x Cerbo GX/Cerbo Touch 50.

Now that I have my system online and charging (thank you Stefanie for the expert advice on the jumper wire :-)

Here's the new issue: The DC side of things works as it should, however, when I turn on the Multiplus II the system tosses out the following error:

VE Bus system (276) - low battery: alarm.

However, the battery bank is not anywhere near low - in fact, it is fully charged (see photos below).

I have tried clearing the alarm and re-initializing the inverter - and I continue to receive the same alarm...

Does anyone have any ideas on what may be going on with my system and how I should proceed to get the AC side of the system online and operational?




snakesteve asked
Stefanie commented ·

2 Answers

Phoenix Inverter 3k 120V and Quattro 5k 100A 230V on same VE.Bus?

I have the following:
-a Phoenix Inverter 3k 120V for my 120VAC/60Hz equipment
-a Quattro 5k 100A 230V for my 230VAC/50Hz equipment
-a Cerbo GX

The Quattro is now connected to my Cerbo providing excellent data regarding my power usage. I understand the DC usage reflects the power being consumed by the Phoenix inverter.

Can I connect the Phoenix inverter to the same VE.Bus for more insight into the AC loads or other data?


rspott asked
rspott answered ·

3 Answers

State of Charge of the Multiplus II is incorrect

I have a problem with the state of charge of the Multiplus II/VE.Bus.

If the battery (30kWh LiFePo4 self bulid with Chargery BMS and Active Balancer, configured as a 2 way signal BMS), is e.g. at a SOC of 20% and the sun starts shining, and the current is eg. 150A the state of charge jumps to 90%, but in reality (on the BMS) the SOC is 30%.

If then, the battery on this day didn't charge to 100%, the SOC is wrong. I.e. that overnight the battery is getting lower and lower. The VE.Bus system "think" its e.g. on 50% and is still de-charging, but the real battery state (BMS) is at 10%.
So the ESS setting which is e.g. at 30% has no effect.

mswoboda asked
shaneyake commented ·

10 Answers

Dual Victron Multiplus, same battery bank, separate AC out.


I need some assistance. I´m installing a setup composed of a battery bank (lithium), 2 smartsolar MPPT, 1 Cerbo GX, two Multiplus II - 48/5000. (240VAC)

The system is installed and it is working fine, but I can´t find a way to only have one inverter/charge working. I understant that when configuring the inverters in split/parallel/three phase, if one shuts down, the other one also turns off.

But one this case, I don´t need to combine the power of both inverters. I have the AC-out´s connected to a swich on the AC switchboard in which we use either one inverter, or the other. So we would like to use the inverters as indepent as possible.

Right now, I have them connected to the Cerbo GX, each with their own VE.BUS cable. I´ve tried chain one VE.BUS cable from one inverter to the other and then to the Cerbo GX, but it is the same, I cannot use one inverter without the other.

Is there any workaround to this? We just want to have more redundancy with the setup, we don´t need to have the combined power of the inverters.

nuno-silva asked
dliska commented ·

2 Answers

Parallel Multis not inverting, showing LED OK codes, CCGX says Inverter is OFF.

We have 2 x Multis in parallel (2 x 48/3000/35-16, V.430).

Multis were set up as master and slave using an MK-2 with VE.Configure software. Multis linked together with RJ45 cable. Master is linked to color control via VE.Bus. System has worked flawlessly for 4 years.

Now the inverters won't invert. No unusual usage, nothing unusual on visual inspection. No error codes shown on CCGX log. Device list says inverter state is off.

Multis LEDs show "OK codes" (ie. Master shows bulk flashing and nothing else, Slave shows float flashing and nothing else, all other LEDs are off). Should both master and slave show Bulk and Float LEDs flashing in a parallel setup?

RJ45 cables are not damaged. The Battery is at 100% SOC, (Lithium BYD B-Box Pro 10 KWh on VE.Can to CCGX)

We have tried turning off both master and slave independently to force a single inverter to take over as standalone inverter but no success.

We have rebooted CCGX. We have checked cables, unplugged and plugged them, turned multis on and off in various sequences.

Does anyone have any solutions?

Thanks in advance.

kayutek asked
Guy Stewart (Victron Community Manager) answered ·

1 Answer


247 Posts
218 Users
1 Follower

Topic Experts

0 Points
0 Points