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superchargedpolo asked

Fronius / Multiplus II ESS - Network Issues?

I am about to install a grid tied Fronius AC PV inverter to a Victron Multiplus 2 ESS system with Pylontech batteries.

The original plan was to use one Energy meter ET112 and a network connection to the Fronius. My supplier has said there can be issues with a system set up this way. See explaination below:

For the Fronius to appear on the Cerbo, they need to be on the same LAN subnet and that requires the local LAN router to be operating even if there is a power failure. SOmetimes the networking causes them to stop talking and it needs reinitialising. And all manner of networking issues. An energy meter with a direct cable is always more reliable.


Would I therefore be better using 2 energy meters ET112’s and forgetting about the network connection. This would also mean I could order the non WLAN Fronius, which is a bit cheaper?

Any thoughts or experiences appreciated.

ESSEnergy MeterFronius
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wkirby answered ·

The beauty of using a Fronius PV inverter is the network communication between it and the Cerbo, it's a wonderful partnership. There are a great many installations set up this way and the work splendidly. Replacing all of the functionality of the Fronius with a simple energy meter would be a real step backwards. The Cerbo will loose the ability to control the Fronius' power output for example and you'd have to rely on the more crude frequency shifting option.
I'd recommend using a wired network connection to the Fronius and the Cerbo for maximum reliability. If your network LAN is set up correctly, then you should not have any problems at all.
A supplier might recommend people to not use LAN because either they don't know very much about networking and are scared of it, or they don't want to help with peoples badly designed network LAN setups, which is understandable.
When using a LAN, it is your responsibility to ensure it is set up correctly and is going to be reliable to ensure trouble free operation.

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superchargedpolo avatar image superchargedpolo commented ·
Thanks for the detailed feedback. Very much appreciated. I will look into a hard wired connection. I much preferred this option. Thanks Craig
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