question

odnacon avatar image
odnacon asked

Very weird Power Output graph in VRM

I have a very weird problem in my ESS system that I have been struggling with since the install. Some weeks back during a troubleshooting session I stumbled upon a behaviour in VRM that I cannot explain and might have something to do with my problems.


screenshot-2023-07-22-at-221854.png


As you can see in the screenshot, one of the phases (the black one) is reporting basically zero consumption - that is absolutely not the case. I do logg input from the ET340 device separately too, and below is what that looks like:


screenshot-2023-07-22-at-224324.png

Yellow is corresponding to the black line in the first screenshot, representing the third phase, and the additional blue line is exported power (read from the grid meter).


Around 9PM the black line stars to oscillate, that is when I switched the ESS system over from "Keeping batteries charged" to "Optimized". Then it ran out during the night and started to charge again as the sun came up. After that I turned it back 'off' to "Keep batteries charged" and have kept it there since.


Anyone who has an idea about what could cause this o have seen anything similar in the past?

ESSvrm advanced
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2 Answers
mvas avatar image
mvas answered ·

What model # of inverter?

Are they identical models, with identical firmware. All three connected to same battery bank?

Power off . Remove the wires and inspect the connection, especially Phase 3. Can you swap the set of Phase #3 wires with Phase #1 or #2. The inverters may need to be informed of this change? Too see if the problem changes phase or not?

Faulty meter?

Can you put a clamp-on amp meter on phase #3 and compare to graph. Is the meter accurate or wrong? Start establishing what wiring and what is not working


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odnacon avatar image
odnacon answered ·

Good and very relevant follow-up questions. I have done quite some troubleshooting and parts of that is what you have suggested.

I have a three-phased Multiplus II 5KVA set-up, they are all on the same firmware and connected to the same battery through Lynx Power In --> Lynx Shunt --> Lynx Distributor to the inverters.

On the AC side, I have switched the 2nd and 3rd phase and reconfigured the MPs to reflect that change. This weird behaviour 'also switched' meaning the weird behaviour stayed with the physical unit. I haven't moved any DC cabled around, yet at least. Something that I could try. Also good idea to check with a clamp AMP meter. Haven't done that either.

What I did notice last time I reconfigured and switched the AC phases was that during start-up, I ran only on battery before turning the grid back on again. And things seemed fine until I switched the grid power back on, then more devices turned on... this is something that I haven't been able to figure out how that could happen...

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Related Resources

What is ESS training video

ESS Quick Installation Guide

ESS design and installation manual

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