What hardware would I need to monitor?

Hello

I'm interested in monitoring my electricity and water consumption, but also my electricity production with PV panels. That is how I came across your website. But I'm not totally sure what I need.

The specifications of my connection (in Belgium) to the grid are 3x230V, one fase, 25A, 5,8kVA. I have one Ferrarismeter, which is situated about 30 meters from the house. There is only one counter, so there is no difference in day or night. There is no socket over there.

I have a zero energy/passive house, so that's why we decided to have an electricity panel for all the electricity outside and an electricity panel for all the electricity inside the house. In this way we don't need to “perforate” the passive part of the house too much. Close to both panels, there is a socket.

Our structure is as follows:

Grid connection ↔ electricity panel nr. 1 + water meter ↔ electricity panel nr. 2 + PV-panel meter.

The water meter is from Elster and looks a lot like this one. The PV-panel meter is a “EM10 DIN energy meter”: I found a topic about monitoring it with Flusko and also the specifications.

My questions are: what do I need and where do I need it? What I think:

  • EmonBase - Raspberry Pi web-connected base-station. Could be whereever, as long as it is in reach of the network.
  • At electricity panel nr. 1
    • EmonTx V3
    • AC-AC Power Supply Adapter (Euro plug)
    • 3x “100 A max clip-on current sensor CT”
    • What would I need to monitor the water meter? I found this OEM-article  which led me to Enica, but this doesn't seem to be available in the OEM-shop. Could I find such meters in Belgium?
  • At electricity panel nr. 2
    • What would I need to monitor the “EM10 DIN energy meter”?

I'm in the IT sector, so installing software or programming should cause a problem that can't be solved. I only have very basic knowledge of electricity and electronics. Any help or tips would be appreciated.

Robert Wall's picture

Re: What hardware would I need to monitor?

"What I think [I need]:
EmonBase - Raspberry Pi web-connected base-station. Could be wherever, as long as it is in reach of the network."

Correct. It uses a wired Ethernet connection - assuming you want to use emoncms.org or another server on your network for logging the data. Or you could run the full emonCMS on the Raspberry Pi with an attached hard disk, or a cut-down emonCMS on the Raspberry Pi with an SD card (but less reliable due to SD card life).

"At electricity panel nr. 1
EmonTx V3
AC-AC Power Supply Adapter (Euro plug)
3x “100 A max clip-on current sensor CT”

Correct. You have a 3-phase supply? Note the default sketch is for single phase only - you will need a programmer to load a new sketch.

"What would I need to monitor the water meter? I found this OEM-article which led me to Enica, but this doesn't seem to be available in the OEM-shop. Could I find such meters in Belgium?"
There are very many threads on this website about water meters. The easy way is to install a new meter in series with the existing one (is that owned by your water company?) that gives you a pulse every n litres, which you feed into the pulse input of the emonTx. Alternatively, it might be possible to fit a pulse output module to your existing meter. If you want to "read" your existing meter, I have seen a device http://openenergymonitor.org/emon/node/5779 that uses a camera to optically read the meter , then OCR software to process the image. I do not know the cost, how reliable it is, what is needed to install it, nor indeed how it would interface with emoncms (I presume it would interface directly with your RPi, then you'd need to customise emonHub to read the data).

"At electricity panel nr. 2
What would I need to monitor the “EM10 DIN energy meter”?"

Do you want to monitor that meter? You would have EmonTx Nr.2 (+ AC adapter + CT) located at Panel Nr.2 to monitor the PV. You could monitor the optical pulse output, but a CT is our preferred method and gives you instantaneous current and power.

m2ts's picture

Re: What hardware would I need to monitor?

Hello Robert

Merry Christmas! And thank you for your answer.

About the supply. My papers tell me 3 x 230V, single fase. Is that possible? Would I need 3x “100 A max clip-on current sensor CT” or only 1 instead of 3?

About the water meter. Looks more complicated that I thought. One would hope that there would be a kind of standard in Europe to read out those things, but apparently not :-(. I'll focus on the electricity part and see how far I get with that :-).

About the PV: a CT is the preferred method. Now I'm trying to figure out if I have type 1 or type 2...

Robert Wall's picture

Re: What hardware would I need to monitor?

Don't let "type 1" or "type 2" worry you - it's our notation and it's only a matter of where you put the CTs in relation to where the PV infeed joins the main installation - basically, do you measure the nett grid power and PV infeed (type 2); or house load and PV infeed (type 1).
[And thanks for the link - I can never remember which is which!]

"My papers tell me 3 x 230V, single fase. Is that possible?"
Now that's got me completely confused - unless it refers to your inverter. If it is your inverter, it means there are three single-phase units inside the one box, and they operate independently.
I shall assume that you really have a genuine 3-phase supply. To prove it, you can look at the wire colours and measure voltages.

If your main wiring between the meter and your distribution board is Brown, Black, Grey, Blue with Green/yellow as the protective earth, and/or wires are labelled L1, L2, L3, N, then you have a 3-phase supply.

To be absolutely certain, you can measure voltages. With the greatest care:

Measure Earth to N (blue). You should measure a very low voltage <10 V.

Measure Brown (L1) - Blue (N) - you should measure ~ 230 V.
Measure Black (L2) - Blue (N) - you should measure ~ 230 V.
Measure Grey (L3) - Blue (N) - you should measure ~ 230 V.

Measure Brown (L1) - Black (L2) - you should measure ~ 400 V.
Measure Black (L2) - Grey (L3) - you should measure ~ 400 V.
Measure Grey (L3) - Brown (L1) - you should measure ~ 400 V.

And a Merry Christmas to you too.

m2ts's picture

Re: What hardware would I need to monitor?

Hello Robert

If I look at the colors: it will be a three fase. You wrote that the default sketch is for single phase only - and that I will need a programmer to load a new sketch. I searched the forums if somebody had done this before, but unfortunately, I could not find anything.

I'm still unsure what "type" I would need to monitor the solar panels. Maybe the pictures as an attachment can clarify some things: there is a pic from the grid ; one from panel 1 (for electricity outside) and one from panel 2 (for electricity inside the house). The blue rectangle is the connection to the grid ; green the connection inside <-> outside and yellow is everything about the solar panels.

 

m2ts's picture

Re: What hardware would I need to monitor?

I used "3 fase" and "three fase" as a search term, but now I see that "3 phase" and "three phase" returns much (much) more results... I will have to read a lot I guess...

Robert Wall's picture

Re: What hardware would I need to monitor?

Ah well, "phase" is how we spell it in genuine English.

And you definitely have a 3-phase supply, but the PV meter is single phase (on Black phase - L2). Therefore your inverter is almost certainly also single phase, and you need only 1 CT for that.

Loading a new sketch is something I do several times each day! When someone asks a question about a sketch and the answer is not immediately obvious to me, or I need to check a detail, I get the sketch, edit it as necessary (e.g. if the radio frequency is not the one I use) and reload it. Today, I have been trying to establish some data to show how random noise affects the CT input circuit. I have made small changes and loaded that sketch at least 9 times this evening.

What determines the type of installation is where you can put the CTs.
If you put 3 CTs on the grid connection - the 3 cables into the bottom of the main incoming isolator (blue rectangle square) and one on the black cable of the PV meter, you have a Type 2 installation.
Here is all you need to know about "type" (unless you have an emonGLCD):
In emonCMS, you do the maths to give you the answers you want:
The grid power may be positive (importing) or negative (exporting).
The PV infeed will be positive when you are generating, and negative at night (but only a few watts to keep it alive).
You measured your grid power, you measured your PV power, therefore your house consumption = nett power imported + PV infeed, and you know everything you need to know.

m2ts's picture

Re: What hardware would I need to monitor?

I've started to read a bit more, but the more I read, the less I seem to know :-(.

Although this article doesn't mention it, I seems to be about single fase only. Than I read about "measuring 3 phase-power", but that article talks about 3x emonTx. There is a foot note that says "One emonTx with an off-board extension to accommodate two additional voltage sensor inputs, connected to the two unused analogue inputs on the I2C connector, and suitable modifications to the library and sketch, should also work". But I don't know what that means, is a "sensor input" the same as a CT?

You don't talk about 3x emonTx, but about 3x CT, namely "If you put 3 CTs on the grid connection - the 3 cables into the bottom of the main incoming isolator (blue rectangle square)". I guess you are talking about "elec outside (P1030089).JPG", blue rectangle, 1 CT on black, 1 CT on grey, 1 CT on brown and nothing on the blue N-cable?

Than you talk about "and one on the black cable of the PV meter, you have a Type 2 installation." Then I guess you are talking about "elec inside (P1030094).JPG", yellow rectangle, brown cable (on the picture it looks black, but it actually is brown). The problem is that this isn't close to the panel "outside" the house, so I guess I will need a separate emonTx for that.

Robert: thanks a lot for your help (and patience) so far!

Robert Wall's picture

Re: What hardware would I need to monitor?

"I've started to read a bit more, but the more I read, the less I seem to know :-(."
It can be like that. Hopefully, the mist will clear as you begin to understand more.

Single Phase is the standard in the UK for domestic installations, so everything about OEM is designed for single phase. The note "two additional voltage sensor inputs" means you make two more ac adapter inputs on a separate PCB (or stripboard) and wire them to the unused inputs AI4 & AI5. That's easy with the emonTx V2, not easy with the emonTx V3. That solution should be more accurate than the 3-phase sketch, which uses only one voltage sensor (the ac adapter) and hopes that the voltages on the other two phases match reasonably accurately.

Elec outside. Yes, that is what I was talking about. You can use the 3-phase voltage sketch on the emonTx V3 'outside'. You do not measure the Neutral because it carries the vector sum of the currents in the 3 phases, which ideally is zero!

Elec inside. OK, a brown cable makes sense, it is L1. (We never had that trouble when the UK standard colours for 3 phases were red, yellow & blue!) Does that brown feed from the inverter to the 'inside' distribution board run anywhere near, say within 10 - 15 m of, the 'outside' distribution board? If it does and the cable is accessible, you can put the CT anywhere on the cable and extend the CT with some 'microphone' or Ethernet type cable to the emonTx.
If that is not practical, then yes, unfortunately it does mean a second emonTx and ac-ac adapter.

A thought: What is your air-tight barrier made of? I hope it does not have foil-backed insulation in it. If it does, you could have big problems getting the radio signal through from emonTx to RPi.

m2ts's picture

Re: What hardware would I need to monitor?

"It can be like that. Hopefully, the mist will clear as you begin to understand more."

I ease my mind with the fact that it is all physics and mathematics, so it should be all logic... in the end :-).

I have a spare ethernet cable and a spare coax cable between the 'inside' and 'outside' distribution board. I guess those cables are about 5 metres long. So that could be doable.

The air-tight barrier is made of two 12 cm PIR insulation... with foil backed insulation :-(. The wireless signal strength drops, but I think it is still okay. Maybe I will need an SMA antenna to be sure?

I guess what I would need is:

  • EmonBase - Raspberry Pi web-connected base-station. Could be whereever, as long as it is in reach of the network.
  • At electricity panel nr. 1
    • EmonTx V3...
    • ... with SMA antenna
    • AC-AC Power Supply Adapter (Euro plug)
    • 3x “100 A max clip-on current sensor CT” to measure the 3 phase grid connection
  • At electricity panel nr. 2
    • 1x “100 A max clip-on current sensor CT" to measure PV. The CT is extended with the spare ethernet cable, so I can connect it to the EmonTx at panel nr. 1.
  • Programmer - USB to serial UART, because I need to load a new sketch onto the EmonTx.

Am I correct about this?

Robert Wall's picture

Re: What hardware would I need to monitor?

I think that is what you need.

Ideally, to extend the CT I would use (and I have used) twin screened microphone cable - 5 metres is not going to be a problem. Unscreened Ethernet (UTP) cable (as long as it doesn't carry anything else) should be OK over that distance, but if you run into problems with it picking up noise and interference, you'd need to replace it with a screened cable. I do not recommend the co-ax cable for this.

Check Glyn's (blog?) post about antennas before you buy (but I think the emonTx V3.4 comes with an antenna).

m2ts's picture

Re: What hardware would I need to monitor?

I thought I ran out of questions, so I went shopping, but apparently I can configure some options...

  • EmonBase
    • RaspberryPi RF: probably best to go with 433MHz, according to this forum post? I guess this is a legal frequency in Belgium?
    • Raspberry Pi Model B+
    • Pre-Loaded microSD Card
    • Raspberry Pi Model B+ Case
  • EmonTx
    • RF Module: 433 MHz
    • Node ID: 10 (default). No idea what this is (at the moment), but the default seems like a safe choice ;-).
    • Fully assembled
    • AC Power Adapter: Euro Plug
    • SMA antenna is already included (like you thought)
  • 4x “100 A max clip-on current sensor CT"
  • Programmer - USB to serial UART, because I need to load a new sketch onto the EmonTx.
  • Shipping to Belgium: there are some options. "Royal Mail (International Standard)" is the cheapest, but I guess it is safer to go with "Royal Mail (International Tracked/Signed)"?
  • Payment:
    • "Bank transfer" is probably something like this SEPA bank transfer? Although I would do an digital SEPA bank transfer, with an IBAN number.
    • I read in Payment, TAX, Shipping & Returns: for International IBAN and SWIFT payments. Please ensure you settle all associated transaction fees; if not, then in addition to the payment shortfall, we will charge a fee of 30.00 GBP to cover administrative costs incurred. I don't know if any such fees are applicable to my situation in Belgium?
    • VAT: as I'm living in Belgium (Europe), I'll have to pay an UK VAT of 20%.

As for shopping: I really hope that I don't have any more questions. But for sure I'll have some when all of this arrives at my home ;-).

Robert Wall's picture

Re: What hardware would I need to monitor?

You need to check the law in Belgium regarding the frequency, because it's you who will pay the fine if it's wrong! I think your national regulator is http://www.bipt.be/, and it is they who are the authority on this matter.

Tracked shipping should indeed be safer.

You'll need to email the shop to ask about payments - or maybe one of your Belgian colleagues can advise you.

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