Again a newbie with good will but limited electricity knowledge… I have read, searched and tested, but I am certainly missing something.
Testing a new install with 6kW PV, Smart Solar MPPT 150/100, Multiplus II 48/5000/70, Cerbo GX and x2 Pylontech US5000, it has worked fine with directly connected loads. But I have now enabled ESS assistant and connected the AC out 1 from the Multiplus to a dedicated DCB type A in the house electrical AC board. When the inverter fonction of the Multiplus is enabled, the differential interrupts instantly. Any hint on the cause?
My intention is to have the house use the PV production even if it will require grid supply to complement the total loads that may exceed the PV supply.
Thank you!
Ok, for beginners :
The differential switch watches over l and n lines and check that the load is equal.
With you, this is not the case, so there must be some current going to the ground wire.
You might try changing the setting of the ground relay in your multiplus.
Thank you Ludo for your suggestion. Unfortunately or gracefully, I might guess 
the relay setting for the inverting is greyed out as ESS assistant is activated.
Guessing doesn’t help you here…
Plase don’t get me wrong. What I mean is due to my limited knowledge, I assume it is greyed for a reason, even if I do not know what that reason is.
The issue must be on the integration of both AC sources as when I run a load (such a small air heater) directly from the Multiplus AC out 1 through the same DCB, it does not interrupt. Is the “AC in” needed for the Multiplus to detect and sync both sources? I have just tried that, and it did help, but again I may be missing something.
When connected to the grid, this relay must be off, when running offgrid this should be on.
You’ll have to check the ESS documentation…
Can you draw a schematic of how its connected?
This is not the way to connect… thats why its tripping
Grid needs to be on ac in, and all loads you want to feed from battery need to be on ac out
or use the system grid parallel, with no backup
Please read the manuals…
Thank you Marc! Of the different scenarios possible, what I am exploring is the way to have the PV energy cover as much as possible of the house loads, and be complemented by the grid as needed when not enough, rather than having a back-up system.
If I understand correctly, “AC in” isn’t only meant to provide the needed energy to charge batteries should you want to do so, but also as a pass through of grid energy to the loads when the “solar energy” isn’t sufficient. Did I get it right?
Might the following schematic drawing be a way forward for my intended use? Of course taking into account the feed-through current limit for the Multiplus model, 50 amps in my case.
Anyhow, this is more a series set-up and not the parallel shown on the bottom left on your image (for non critical loads). If so, isn’t it that what the original drawing showed (even if the AC in was indeed missing)?
As always :
Error 1, manual not read.
If you connect it like youre second drawing everything should be fine, this way you also have power from batteries as a backup,
Your first drawing is also possible but not on ac out, it needs to be on ac in and you will need a grid meter, then it is a grid parallel setup
I will get the needed cables and I will confirm the outcome. Thank you very much for your kind help!
I have proceeded based on Marc’s feedback with my second diagram and it now works fine. I have had thought to restart the Mltiplus via the VE Config. Is there an alternative way I might not have read? The switch on the unit as well as the remote switch via the remote console did not work to turn the unit back on. I will be doing some other testing before closing the feed.