question

peterh avatar image
peterh asked

Inverter goes to 'passthrough' as soon as contribution from PV/MPPT's drops below AC Load

My system is a new system based on two Multiplus II 3000/48 connected in master/slave, two 150/45 MPPT's, CCGX, and a BlueNova battery connected via Canbus.

I have the latest firmware installed on the MPPT's, Multi's, and CCGX.


When the system is physically disconnectted from the grid it is functioning perfectly supplying the critical loads and charging the battery during the day and running off battery at night.

I'm currently trying to implement ESS.

During the day when the contribution from the MPPT's exceeds the AC critical load it functions as expected in charging the batteries and supplying the critical loads.I have set the grid setpoint to -20W to always have a slight export to the grid.

However as soon as it starts getting dark the inverter switches to passthrough mode and supplies the load from the grid even though the battery SOC exceeds 98%.

Are there any other settings on the CCGX or the Multi's that I am missing?



ESS
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2 Answers
Rob Duthie avatar image
Rob Duthie answered ·

Hi
With lithium batteries turn off the mode for battery life to off without as this makes big difference how the ESS system works only designed for lead acid.

Had a a similar issue.

Regards

Rob D

NZ

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peterh avatar image peterh commented ·

Rob,



I can't see that it's possible to disable the BatteryLife option

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peterh avatar image peterh commented ·

Now I understand what you mean - and have switched off

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Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @PeterH

I'd check the options at Q9 of the ESS faq first:


https://www.victronenergy.com/live/ess:design-installation-manual#faq

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peterh avatar image peterh commented ·

Daniel,


Have checked everything on the list and can find no issues.


have also disabled the BatteryLife option and reduced the battery voltage limits.


The chart below shows what is happening.


During the day run off the solar only.


As the sun sets there is a brief period where there is a contribution from grid, solar, and battery.


Then goes onto passthrough and runs off grid only.


The following morning effectively transfers back to solar.


Until I can resolve this problem am every night now switching off the supply to the inverters (grid failure), and running the whole night off the battery.


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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ peterh commented ·

Hi @PeterH

What is your VRM id? I can take a look if you want.

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