Multiplus-II inverter not switching On with VE.Bus cable to Cerbo GX Connected

DIY
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1

Multiplus-II 48/15000/200-100 230V connected via VE.Bus to Cerbo GX does not switch ON either from the Cerbo GX or the inverter switch once powered down. It can only switch ON once the VE.Bus cable is disconnected. However, it can properly switch off either from the Cerbo GX or inverter switch with Vee.Bus cable connected
Final Settings.vsc (5.8 KB)
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Once I plug back the VE.Bus cable with the inverter ON, everything works properly i.e. the Cerbo GX could display the output AC power from the inverter, correctly monitor the inverter status and correctly control turn-off the inverter.

Both the Cerbo GX and inverter are running the latest firmware. Updated their firmware versions on 19 March 2025.
What could be wrong?

2

Hi, just confirm that the GX is on 3.54 not a beta version? Thanks

3

Hello, Yes. The GX is running the version 3.54 and not beta.
venus-swu-einstein-20250128120635-v3.54

4

Thanks, and you confirmed on the GX that in the inverter tab, the soft switch was not set to OFF?
This is about the third recent post I have seen.

What batteries are you using?

Are you able to reproduce it? If so, can you try the redetect vebus system option in the GX device settings.

5

What is the actual version on the inverter

6

You are welcome.
Confirmed, the soft switch in the GX device was set to ON and it goes to OFF when the inverter is off. I have also tested that I can switch the inverter off from the GX device by toggling the soft switch but switching ON fails.

I have 6 x Dyness DL5.0C battery connected to the GX via VE Can BMS port. I have also tested without the battery VE Can BMS cable disconnected but doesn’t work.

I have also tried the redetect ve.bus system option multiple times but no luck.

7

Thanks, that helps. So is this reproducible then for you?

8

Hello, I will get you this information soonest.

9

Hello Nick,
No, it is not reproducible at the moment. I do not have another device to test it on. I am planning to visit the distributor in a few week to see if this issue exist on other devices or perhaps just this ones. I will do that and update on the findings

10

Thanks. It has been difficult to help as the issue seems to resolve after the initial install.

11

Hello LX,
The inverter is running firmware version v556 currently.

12

Hi Theophilus, did you find a solution? I have a similar problem.

13

@selwyn
There is an old workaround if it persists.

Q20.

14

Yes, I used the Q20 workaround. See below:

So, I tried powering the Cerbo from other cables coming from the battery in case of some slight voltage drop vs the feed to the Multiplus; it made no difference.

I read in the Cerbo Manual FAQs (19.2.20 Q20) that when using other power sources than the battery you can remove pin 7 from the VE.Bus connector to allow the Multiplus to startup with the cable to the GX device connected.

Tonight I made a VE.Bus patch cable without pin 7 and tried it between my Multiplus and Cerbo. I could turn the Multiplus inverter on/off with the new VE.Bus cable in place without any issues. There was a warning that the Multiplus may take more standby current with such a cable, but I don’t detect any increase.

If all remains well, I will make this modification permanent.

1 Like
15

Thank you - It worked for me too.

I cannot explain why there was an issue, as the GX device is powered from the battery.

16

I didn’t get a solution yet. Im in touch with the distributor. Once we have it resolved, i will update.
Im suspecting a software issue that can easily be resolved with a firmware update.

17

Hi I am having the same problem. I have a Mk 2 new Cerbo and Multiplus II, all with the latest firmware, The Cebo is connected to the battery, Do Victron have a solution for this problem. Thanks

18

I have a 5K MultiPlus II, it sometimes does not turn back on after turning the switch off. The Battery is 87% and charged at 54.25V
I do not have the inverter connected to 230V AC. It is only connected via the battery.
I have been able to get it back on by turning off the battery supply and disconnecting the VE BUS cable, and waiting for 5 to 10 minutes.
The inverter does turn on, but I am not sure what is causing the problem.
I see that the problem might be that the connected VE BUS cable is causing the problem.
What I cannot find is what the solution is.
Is there an easy fix to this?
Thank you

19

Hi @Bluey

I have a troubleshooting step to try and resolve the issue.

Can you remove PIN 7 from the VE.bus cable with a small flat head screwdriver?

The gold pin should be able to be dislodged fairly easily, but make sure it doesn’t fall into the unit.

There is a picture of it here

20

Hi Guy

I was aware of that troubleshooting step.

There is no access to the pins as the cable is sealed.

Does Victron supply a cable with this modification?

I now have more information on the problem.

Regarding the issue with your Multiplus-II not turning back on after using the switch—this is due to the unit being connected to a GX device (such as a Cerbo GX). When connected, the GX device assumes control of the inverter, similar to how a Digital Multi Control (remote) operates.

This means the rocker switch located on the bottom right-hand side of the Multiplus is effectively overridden by the GX device. Once the system is operating under the control of a GX device, the rocker switch SHOULD NOT BE USED to turn the unit off. Doing so can cause the inverter to remain off until the VE.Bus network is reset, as you’ve experienced.

If you need to disable the inverter, it’s best to do so through the GX interface (either locally via the GX Touch screen or remotely via the VRM portal), rather than the physical switch.

Guy, does Queensland have a Victron Service manager?

Thanks