question

petr-malek avatar image
petr-malek asked

Multiplus II stops inverting - a bug or feature?

I have a Victron system for a short time, exactly 11 days and this problem occured already for the third time. For some reason the system switches invertor off (none of LED invertor indicator is on/flashing) . After that one or more phases are consuming 100% from grid even battery is charged enough.

You can see it on the screenshot that this happened today and 01:28 and remained so for the rest of the night.

When I switched off AC in then all of units started to invert correctly. When the grid was on again (7:28) the undesired state (invertor off) remained. At 7:38 I bypassed PV and all of 3 units automatically woke up. After returning back to PV the system is working as desired.

Is it a known problem in firmware or configuration? VRM log shows no alarm, no error.

Thank you.

MultiPlus-II 48/3000/35-32
Firmware version 494
ESS, Three phase system, one unit per phase

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20220411gridoff.png

Multiplus-II
20220411.png (133.8 KiB)
20220411gridoff.png (87.5 KiB)
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ejrossouw avatar image ejrossouw commented ·

I agree with nickdb, but check if a minimum SOC is set in ESS? What is the inverter state shown on the VRM dashboard when this happens?

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petr-malek avatar image petr-malek ejrossouw commented ·

The minimum SoC is set to 20% which is much lower than 50%+ when happened. Inverter state is whole time "bulk".

99% of time the system is working in a perfect way. 2 of 3 occurences of this situation were in night while low consumption without any obvious reason.

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nickdb avatar image
nickdb answered ·

Why do people who don't understand the product automatically assume a bug?

It is almost always poor installation and/or configuration.

3-phase is a complex system and you have not provided nearer enough detail to try give advice.

So can you send a wiring diagram? Copy of all the inverter settings? Details about the batteries?

The internet is a bad place for complex diagnosis of faults.


You should get your installer to check it for you, if this was DIY then perhaps find someone who can help you in person.


There is plenty of important reading:

https://www.victronenergy.com/live/ve.bus:manual_parallel_and_three_phase_systems

https://www.victronenergy.com/media/pg/Energy_Storage_System/en/index-en.html


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Alexandra avatar image Alexandra ♦ commented ·
@Petr Malek

Just to add on here, If the inverters have ess then the inverter has a dynamic dc cut off. So under some low loads it will shut down the inverter before a low SOC is reached.

Your installer is the guy who should be troubleshooting this or have some explanation for its behaviour.

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petr-malek avatar image petr-malek Alexandra ♦ commented ·

@Alexandra

I had several calls with the installer (installed already more than 50 systems like this) and they were not able to explain it. That was the reason I tried to ask somebody here if this behaviour is known.

If the inverter was switched off by the dynamic dc cut off then it is certainly a feature based on configuration.

Unfortunately, there was a significant load that did not wake up inverter as I would expected. Thanks for the hint, I will use it with further investigation with installer.

screenshot-2022-04-11-131057.jpg

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