question

Hi Marek,

My guess is that PE and Neutral have a sporadic connection somewhere inside your installation.
If I remember right this is not the first time happening. This happened months ago too, where we talked why this can happen.

I would suggest to repeat Step 3 and not just switch off the breaker, but disconnect L and N from your house installation but leave the Multis N connected together.

If the system is working again while disconnected from your house installation, you might be on the right track.

Best Regards

To all that follow this topic.

Victron service decided to replace my L2 master Multiplus-II because they suspect it has back-feed relay problem (sticky).

Update and question.

Since that Error #11 back in August, system is working OK.

Master MP-II on L2, that Victron decided to replace, is still waiting to be replaced.

Replacement process is stuck somewhere.

For the last 4 months did not get any errors #11, but I do not know if this is because the relay is OK or it was not tested, since system was always up and connected to the grid.

During those 4 months system switched to inverting and back over 25 times.

Can someone tell me, how often the back-feed AC-in relay is tested?

Regards to all,

Marek

Will this help to test this problem

Hi Marek ,been chasing my tail with this error 11 too.

see here

https://community.victronenergy.com/questions/30559/grid-code-selection-south-africa.html?childToView=177559#comment-177559

Here are some of the clues I have come across so far

There are no switches on my Multiplus 2 as set out in one of the solutions to indicate open or closed

How the test is conducted :

Here are some work around that did not work for me

https://www.youtube.com/watch?v=UCbk8ntxyZg

https://www.youtube.com/watch?v=GXBqwDZqi80

https://www.youtube.com/watch?v=OU4x5CqiJdw

If everyone who has this problem asks for a new Multiplus perhaps we can get to the bottom of this enormous waste of time

I know when i remove the ess assistant and grid code for South Africa the error goes away.

Some say that multiplus are not anti islanded however this is not true however

"The Multigrid is a specific variant of the Multiplus that has the anti-islanding built in
A MultiPlus, plus ESS (Energy Storage System) functionality- The MultiPlus-II is a multifunctional inverter/charger with all the features of the MultiPlus, plus an external current sensor option which extends the PowerControl and PowerAssist function to 50A resp. 100A. The MultiPlus-II is ideally suited for professional marine, yachting, vehicle and land based off-grid applications. It also has built-in anti-islanding functionality, and an increasingly long list of country approvals for ESS application. Several system configurations are possible. For more detailed information see the ESS Design and configuration manual.
Note according to victron brochure :" for a short period of time this product was called MultiGrid-II."

Multiplus II 48/5000/70-50 product id 2623 running firmware 500 , serial no HQ1918U9F4l which according to spec sheet is compliant with grounding requirements .

I keep getting ve bus error 8/11 reports phase l1 device 1 (0) #79 0x800805 errors

been through all the steps below

Steps to take: Step 1: Make sure that the units have been updated to the latest firmware version. There have been various VE.Bus error 11 related improvements in the firmware. This may correct the error, and if it does not, it will provide additional information to assist troubleshooting.

Updated to v500

Step 2: Verify that system is properly wired to your installation and your local codes. Remember to check the earth connection on the unit AC input. Earth should be grounded according to your local grid rules. Do not connect Earth to Neutral in the unit itself.

neutral not connected to earth in unit only at service input

Step 3: Disconnect the L and N wiring from the ACout terminals on each inverter/charger. Which, in case of a parallel or three phase system, isolates the ACout connections for each unit. If the system then starts normally there might be a problem with a connected load (e.g. a leakage between load, neutral and ground).

done that no difference still error 11

Step 4: Check your Neutral-out connection. In most cases there should be no external connection between ACin-Neutral to ACout-Neutral, or to Earth

  
                  

                   
no continuity detected  
                  

Step 5: Neutral and line input might be inverted. Check the input connections, swap them if needed and retry. In this case, “Failing step: 8” will show.

I see step 8 in error code but Step 5 mitigation above had no effect

Swapped the N and L no difference still error 11

I cant get info on why I don't have a switch but a green connector block with GRD Relay slot . Is this the same as the switch ad should it be shorted

I see some installs that have a chassis ground to Neutral bar see below but this must be for a vehicle and not a grid tied connection using ess

Must be faulty relay on Multiplus - ie warranty claim

I think that the Multiplus needs replacing as it looks like the relay.

To all that follow this discussion.

During the 2022, I was investigating this problem and after many tests and different configurations, I am 99.99% certain that the L3 slave MP-II was the culprit. This unit was getting progressively bad and at the end it would turn off by itself at random moments causing all kind of errors many times during one week.

After replacing it on 10.08.2022 after getting errror #3 again, I did not get any errors since.