moeterxl avatar image
moeterxl asked

Multigrid AC coupled Fronius shut down on grid failure

I`ve got an question about gridfailure and disabled Fronius PV- Inverter AC1- coupled.

My system: Multigrid 48/3000/35-50 with Venus GX and two connected Pylontech US2000 Plus. A BlueSolar 150/35 is DC- connected to the Multigrid. My Fronius Primo 3.0-1 is AC-1 connected to the output 1 of the Multigrid. The gridmeter is an ET340. All firmwares are up to date.

Today our grid in the village is running at APU by the energy supplier because of repair. They`re setting up the grid frequency to 51,7Hz for turning off all the PV`s in the village. The Multigrid detect a grid failure and disconnected to grid. At AC-1 output the frequency is 53,0Hz and the Fronius is switched off. Shouldn`t it use the Fronius energy to charge the batteries by Multigrids internal charger? What`s the reason of this reaction?

Venus GX - VGXPylontechFroniusgridmultigrid
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3 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hello Moeterxl,

Your Pylontech batteries are too cold and applying a Charge Current Limit. You can see this in Parameters menu, inside the battery menu on your Venus Device.

Please contact your Pylontech distributor/salesperson and tell them that this is an issue, and you were not adequately notified by the Pylontech documentation that there was charge current limits at temperatures as high as 15 degrees C.

I have been unable to get accurate information from Pylontech as yet about the thresholds and charge current limitations, but if enough customers are also asking, I hope they will respond.

This is the 3rd community question about this issue, So I have taken it as a sign and updated the Victron & Pylontech documentation and make it clearer that these batteries restrict charge current when they are below 16 degrees C.

Other users reporting the same:

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Hello Guy,

i, would check it the next days by switch off the input fuse of the Multigrid if the reaction is the same like overclocked grid.

According to current limitation by temperature i would build an electric battery heating and cooling system. I´ve checked the VGX and Multigrid to control the internal relay in relation to the batteries temperature. Unfortunately i haven`t found any free configurable function at the VE.bus assists and VGX to use the BMS temperature. There`s only temp high / temp low alarm and pre alarm (LED) available from Multi without the possibility to set the switching temperature. This is an important feature for heating or cooling a battery system to his comfortable temperature. Do you have a solution without an external control?

Thanks - Kay

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I think this is a relatively new problem. I also have it myself, it is summer now in Australia, but in the winter my shed gets cold enough that batteries do not charge in the morning.

We may need to create a new feature to address it. Others may also have something to contribute:

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boekel avatar image
boekel answered ·

can you post a screenshot of the battery (BMS) parameters?

-edit- Guy already posted a better answer.

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mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hey, one addition in case someone else comes across this one:

Just like you did, first make sure your Venus-device is running latest firmware. See this one from the v2.20 change log:

“ESS Systems with a grid meter, Fronius Inverters and Zero Feed-in enabled: no longer shut the PV Inverters down when there is a power failure. Instead; let the Multi/Quattro regulate them with frequency shifting. Thanks to Eon F. for reporting”

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