Current sensor for DC

DIY
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1

Hi all

I have the following setup:

  1. Victron multiplus ii 8kva
  2. Battery 12.5 kwh
  3. Cerbo GX (coordinating everything)
  4. Smart solar 250/70
  5. 3 X 580w sharp solar panels.

Victron is connected to the grid.
The “Grid” comprises of two systems:

  1. Actual Grid power
  2. A Net Metering system “Fronius 5kw, BYD HVM 11.04 and 4.92 kw solar panels”

What I want to achieve is to allow Victron to charge the battery from the grid (in combination to the smart solar) when the fronius solar are producing a specific amount of power otherwise I want the system to only charge from smart solar.

Initially I thought that the " Current Transformer for MultiPlus-II" sensor would be able to accomplish that however I later realized that it can only monitor AC power not DC (which will be coming from the 4.92kw of panels connected to Fronius)

Is there another way of capturing this information so that I can feed it to the Cerbo?.

Thank you in advance for your help.

2

Check “solar and wind priority” for the multiplus, that should solve your problems.

But use the current firmware v552, not the 508 that announced this feature.

3

I dont think Solar and Wind Priority is the answer here. That is mostly for DC Solar I though?

You probably want to look into ESS. I am not to versed in that realm, but I believe it has direct tie in with the Fronius.

Edit: This is probably a good place to start.
https://www.victronenergy.com/live/ac_coupling:fronius

1 Like
4

Just answering the simple question, “can I monitor DC current?”, yes you can, you can get a Victron SmartShunt and use it in DC Energy meter mode and connect it to the Cerbo via VE Direct cable. What I can not answer is " what exactly should be measured?", “will this be a useful measurement?” or “how can this measurement be used?”.

5

Hi thanknyou all for the answers.
As I said I have a netmetering with fronius and BYD battery. In want this system to feed AC power to Victron multi so that the multi charges the 48v battery. BUT I want this to take place only if solar production on the fronius is above a certain level.

So what I want to measure through the censor is the current in the solar cables of the fronius

6

I believe the Fornius can measure the Solar Power on its own and report it the Cerbo so that you can program accordingly.

7

I do not think you can use the Victron SmartShunt in the solar input to the controller

8

I have the fronius Gen24 plus. I havent read anywhere how to do that

9

Actually I though of how to do it through home assistant.
Does anyone know If I can control the relays (I have Relay 1 and Relay 2 activated) through home assistant ?
Basically if Fronius reports that solar production is above 1.5kw then relay 1 (which is passthrough with only additional 5A charging) will open. When solar production is above 2.9kw then relay 2 (which is only charging with 40A) will open.
If relay 1 is not open then relay 2 doesn’t work.

Any ideas if I can control Relays through Home Assistant?

10

Anyone tried to switch on and off the relays through Home Assistant?