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kalamgish avatar image
kalamgish asked

ESS Multiplus Wiring

Hi, I am trying to set up an ESS system but would like to check the connections to the Multiplus.

Q1. Reading the ESS design docs it seems you connect the ACout to the grid, is this correct? Does this mean the ACin is not connected?

Q2. I already have a meter which gives me bidirectional power information which I read and use to switch the immersion heater, is there no way I can use this with the multiplus? I send this reading over the local LAN via MQTT,

Q3. Am I better off using the Multiplus in dumb mode ESS mode4? Can you point me to useful links on that subject?

Thanks, see (possible!) schematic below.


MultiPlus Quattro Inverter ChargerESS
multiplus.png (68.0 KiB)
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2 Answers
Rob Duthie avatar image
Rob Duthie answered ·

Hi

AC in from grid goes to the in not out, look at the victron installation manuals!!!.

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kalamgish avatar image
kalamgish answered ·

I was under the impression that the ACin and ACout cannot be connected together.

From the ESS installation manual.

All loads and (optional) grid-tie inverters must be installed on the AC out in a system without a Victron grid meter.

So in a domestic setup where the grid supplies the loads how do you wire the inverter?

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ejrossouw avatar image ejrossouw commented ·

May I suggest you consult with an electrician or professional given if you make notifiable changes to the consumer unit read (add a circuit you) will be breaking the law if you don't have it certified. Also, the DNO has to be either notified and an application made depending on the size of the installation. Finally, your insurance will be invalidated if it is not done "legally" and before I forget, you have to have a type B RCD (NOT B curve) installed when connecting an inverter/battery to the consumer unit. Don't understand much of this or even able to correctly interpret the Victron manual installation diagrams? You are risking lives.

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Rob Duthie avatar image Rob Duthie commented ·

Hi

Read the manuals!!! the grid tie inverter can go any were on the input and output.

Get the installer to do this work a qualified electrician who knows how they work and connect up.

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ejrossouw avatar image ejrossouw Rob Duthie commented ·

Hi

Correct, but it depends on the requirement. If you want the multi as a backup when the grid fails during the day and there is solar available then AC1OUT, otherwise ACIN is fine. I have an ESS system without any ACOUT or solar :)


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petajoule avatar image petajoule commented ·

AC in and AC out cannot be connected together - so much is true.

However, the Multiplus has something called a Transfer Switch and will pass through AC-In to AC-Out the right way, when needed, will synchronize with the grid and will be able to Power Assist...

All very nice things.

Whereas if you simply connect AC-In to AC-out, all you get is smoke and sparks.

Therefore, your UK grid in goes to AC-In, and the house loads are connected to AC-out.

For a thorough demonstration what goes where, please see also: https://www.youtube.com/watch?v=hmUVo0xVAqE

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kalamgish avatar image kalamgish petajoule commented ·

OK, thanks.


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