Converting an off-grid system to on-grid - ESS faults and Multiplus-II LEDs

DIY
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Hello all,

I am working to convert a stable and working off-grid installation to an on-grid system. It has been performing flawlessly so far as a stand alone system but is currently showing an ESS fault. The conversion process has involved fitting a grid meter at the origin of the house grid, and that can be seen on the Cerbo and it is reporting well. The other job was to provide power to the AC-In via a 32A RCBO. The installation itself is in an adjacent garage so goes through 3 consumer units all in all to get there (main house>extension>garage) and I wonder if this is a contributing factor.

Components:

SmartSolar 250|100 MPPT

BlueSolar 250|100 MPPT

MPPT RS 450|200

CerboGX

MultiPlus II GX 5000

Pylontech US5000 x 3 (more to come)

Everything has up to date firmware and has been working very well supplying part of the house from the AC out. It has been this way for several months while the home owner gets used to the system and so that we can get an idea of habits and usage.

Now the time has come to integrate the rest of the house as a whole. The AC-out has become redundant with the AC-in becoming a two way supply and feed. The ESS assistant has been installed but now the Multiplus is showing that it is in an ESS fault condition. The MPPTs are still charging the batteries but nothing is being inverted back to the house. A grid lost error has been reported but I can measure voltage directly (and see in the device section of the display) that there is 238V at AC-in. The Multiplus-II on the Display shows three blinking LEDs - does anyone know what they mean?

The ESS assistant did mention that the gridcodes belonged to a different firmware version but I’m not sure how to resolve that.

The batteries were set up using the handy pylontech/Victron guide. Likewise the ESS design documentation was followed, but I’m at a loss now. The ESS assistant has now been removed and doing this has previously allowed the Multiplus to invert once again, but this time the fault has persisted.

Are there any other parameters or numbers that I can look at to help narrow things down a bit? Or any screenshots that I can provide in return for some sage advice?

Can anyone please offer a solution?

Any help will be greatly appreciated.

Screenshot 2024-08-28 at 11.15.45
Screenshot 2024-08-28 at 11.15.45873×393 51.3 KB

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Hi, you are using a Multiplus GX AND a Cerbo?
The GX.Multi has a “Cerbo” integrated.
What happends, when you unplug the Cerbo and connect wverxthing to the GX.Multi.
Then run the ESS-assistent on the Multi itself.

A false setup Energy meter can cause problems, so check, if it’s connected correctly and displayd right in the console of the GX

3

Thank you for our thoughts Sebastian.
The default grid code applied by the ESS assistant was incorrect for the firmware version and all it took was some (paid) support from my local distributor to enter the correct grid code as these are not freely available as far as I know. System works wonderfully now.

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