What equipment do i need?

(Bruno Christensen) #1


i have 2 installations, one in my house and one in my garage. All my solar power comes in at my garage (3 face)
Here is a pic of my installation:

I cant figur out what hardware i need to buy to measure the total power i buy/sell to the grid and the total power my solar makes.

I hope you can help me find what im looking for.


(Robert Wall) #2

Welcome back, Bruno.

You have a 3-phase supply in Denmark - is that 3-phase, 4-wire (L1 - brown, L2 - grey, L3 - black & Neutral - blue) 230 / 400 V, plus the safety earth? I shall assume it is.

[Your diagram is too small to read - can you post it here, please?]

If you want the best possible accuracy, then it would be one emonPi and two emonTx’s - one measuring each phase. If you are content with reduced accuracy, then you could have two emonTx’s each with the 3-phase sketch, one measuring the grid connection and the other measuring the PV infeed, plus an emonBase with emonCMS to collate, record and display the data.
For the emonPi option, you need 6 c.t’s, 3 a.c. adapters and a d.c. power pack & cable for the emonPi. For the emonBase option you need 6 c.t’s, 2 a.c. adapters and a d.c. power pack & cable for the emonBase.

(“Reduced accuracy” is because the emonTx has only one voltage input, so it must assume that the voltage of the other two phases is the same. How much error that will create will depend on how accurately the voltages are balanced, and you cannot control that.)

(Bruno Christensen) #3

you are correct with the 3 face + nutral and grund.

the phases is almost always in sync.
is there a way to get it “pre setup” so its more plug 'n play?

(Robert Wall) #4

Can you access all 6 wires in one place in the house (3 phases from the PV and 3 from the grid)?

The way with the least work for you would be the emonPi + 2 Ă— emonTx. You would use the standard default sketch in each emonTx, you will need to change the NodeID in one with a switch (but it is inside the case, so a Torx screwdriver is needed), and you will need to set up emonCMS (via a web browser) to record & show the information you desire.

It might still be a good idea to buy a programmer, even though you should not need it.

(Bruno Christensen) #5

no that is in 2 building about 15m apparat.

(Robert Wall) #6

Your diagram showed the two coming together at the house - I had expected that would be at your distribution panel, where you would be able to access all the cables.

In this case, that first option is not available to you. You have little choice but to have one emonTx in the garage, and one emonTx in the house. Plus an emonBase - also in the house, I expect - to collect the data.

You will need a programmer, and you will need to download the 3-phase sketch, customise it according to your needs, and upload it into each emonTx.
And you need the emonBase. You will also need to set up the Arduino IDE on your computer to upload the sketch.

(Bruno Christensen) #7

thx for all your help. i have placed an order.

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