question

AlexCPU avatar image

MultiPlus-II ESS with No AC-Out

I'm trying to work out how to add a MultiPlus-II 5000 for ESS to my existing solar installation.

I think my setup will look like the below image.

Currently I've got the Solar edge inverter and ET112 meter in place.


So I've got two questions that I can't work out (I've checked all the diagrams!):

  1. Can the MultiPlus-II provide power to my house back out through the AC-In, without having to get perform a significant re-wire of the house?
  2. Do I need a CT on the Live from the Solar Edge inverter? I'm aware the CCGX can read the data from the ModbusTCP out of the inverter. But don't know if that's sufficient.
Multiplus-IIESS
victronsetup.png (193.3 KiB)
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

2 Answers
Sean avatar image

1, yes - so it just needs to be connected to your consumer unit via a suitable breaker.

2, Prior to installation of the EM112 I extended the CT approx 30m and simply plugged it into the 3.5mm socket on the MP, which bypasses the internal CT. The external CT goes on the main incoming grid feed. I have a Fronius Primo, and a Fronius smart meter, the generation is seen on the Venus device.

So in terms of your schematic CT? is not required.

Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Rob Duthie avatar image

1: Not really but you can export power by changing the grid set point you can export power and import power. that is not how the ESS system works, you need to have the loads on the AC outs

for the ESS system to work correctly.

2 comments Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1, That's exactly how my ESS is setup - AC-in is bi directional

The CT or smart meter is used to ensure net zero import, using inverted battery power.

You don't have to have loads on the AC-out if you have an energy meter installed (or external current sensor).
If you want to have power when the grid fails, you have to route (part of) your house wiring from the AC-out.