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lazza avatar image
lazza asked

More complex options for Ignoring AC in for 3-phase Multi ii 48/10000 setup

HI

We've just set up a 3xMulti ii 48/10000 system, 3 phase system with a Cerbo GX control unit and pylontech batteries. The user only wants to use the grid when absolutely necessary and hopes to go fully off-grid shortly, once the consumption profile is clear.

So for now, we have the simple VS options: "Ignore AC in" which activates on low battery and excessive loads. This works ok, but we'd like to make the switching more complex and if possible using the Cerbo GX as the main controller.... in short we'd like to:

  • "Ignore AC in" on SOC from the BMS/Cerbo GX, rather than on the Multi's battery voltage measurement.
  • "Ignore AC in" always during daytime hours (expensive rate)
  • "Ignore AC in" when either one of any of the 3 inverters reaches 8kW, and not just the Master

Can anyone tell me exactly how this could be done?

Thanks

Larry



3 phase
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2 Answers
mike avatar image
mike answered ·

Hi Larry, The Node Red image for the cerbo can be of some help here.

info about the image can be found here https://www.victronenergy.com/live/venus-os:large
more info about the node red flow can be found here https://flows.nodered.org/node/@victronenergy/node-red-contrib-victron

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lazza avatar image lazza commented ·
Thanks for the reply. That looks overcomplicated for us though. I was hoping there may be simpler solutions
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JohnC avatar image
JohnC answered ·

Hi @Lazza

Take a look at the Gen Start Stop feature in the Cerbo.. https://www.victronenergy.com/media/pg/Cerbo_GX/en/gx---generator-auto-start-stop.html

It should do much of what you want, but instead of a genset, run a wire pair to the Multis Aux port and process the start signal further. A little like VS, but the Assistants are more capable (and more complex). VS and Assts are mutually exclusive, so it's one or the other. General Flag can be set to control ACIN, and you may find the need for even multiple instances of Programmable Relay Asst if you think up stuff you can't do in the Cerbo.

https://www.victronenergy.com/live/assistants:start

I haven't used this in 3 phase, and you'll need to get your head around how they work, but the beauty is it's all aboard the kit you have already.

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lazza avatar image lazza commented ·
Great, thanks for the suggestion John. I've used assitants before, mainly for ESS setup. Just a quick question on the Aux ports- do you need to provide a voltage for them, or will simply closing or opening the contact suffice?
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