I need your advice on the proper hardware to replace the OWL system.
I have Rpi 3 and I am hoping to use the 3 Current sensors from my old system, Can you please help in the recommended hardware to purchase.
I need to monitor each phase using the web (locally only through the wi-fi) and mobile app as well. I have no interest in a cloud solution. Only local network.
My plan is to use temperature sensors to monitor the temperature in different rooms. through the use of ESP8266’s
The good news is you can use your RPi 3. The bad news is you might be able to use your current transformers, but without knowing exactly what they are (in terms of their ratio, their current output at rated current and their VA rating), I cannot say definitely that you can use them.
What I think you need is an emonTx V3.4, 3 YHDC 100 A c.t’s to measure your 3 phase incoming lines, a 9 V a.c. adapter to measure one of the voltages, a programmer to enable you to load the 3-phase sketch into your emonTx, and you might also need a 5 V d.c. USB power supply for the emonTx; and for your RPi, you either need a RFM69Pi radio module for it to receive by radio the data from your emonTx, or if the emonTx and RPi can be located close together, then you can connect them serially.
The RPi needs emonCMS (which you can either download or you can buy a pre-programmed SD card), and it will receive your temperature data via Wi-Fi (or wired Ethernet).
Before you buy, you might like to look at the download for the 3-phase sketch. In the zip file, you’ll find documentation with all the details that you need to configure and calibrate it.
Great response Robert…
1- 3 CT’s
2- an emonTx V3.4, 3 YHDC 100 A
3- RFM69Pi radio module
4- [email protected] 9V adapters for each line voltages ( I need you to explain how this is done)
5- 5 V 2+A adapter to power BOTH the emon and the Pi
For the temp monitoring, I will need
a- [email protected] + LM35 +power adapter ( for 5 rooms)
Again I do not know how the emon will handle the 5 temp sensors, I presume the software will take care of ( or I program it myself) but i need to know if it is DOABLE or not ??
I did not get that …I thought if the CT’s are close the emon ( which is not in my case)
You see the CT’s will be installed inside the Main Switch board then the RF tranmitter ; connected to the CT’s will send the data to (emon + Rpi) far away in my Den.
The CTs need to be close to the emonTX. The data can then be transmitted via RF to the RPi, but you need to buy an RFM board for that RPi to receive the data (referred to as an emonBase). If the Pi is co-located with the emonTX, you can connect via the serial port directly thus avoid the need for the RFM card and the programmer.
I have to “delearn” …give me a moment…
The CT’s will be connected to the emon. So, the Emon will be located AT the MAINS switchboard
If I also connect the Rpi to the Emon. AT the swithboard, I will NOT need any RF transmission( I like that)
THEN I will have to do EVERYTHING using SSH ( WiFi) from my Den
No, you can have only ONE a.c. voltage input to your emonTx. That is what I wrote. The sketch in the emonTx manufactures the 2nd and 3rd voltages internally in the software. Accuracy depends on the three voltages being sufficiently close together in amplitude. If that is not the case where you live, you need three emonTx’s, one for each phase. This is why I suggested you read all the information first before you order.
You cannot power the emonTx and the RPi from the same 5 V d.c. supply if they are a long way apart.
The emonTx will not handle the temperature sensors. That information will go directly into emonCMS.
Where did you get that idea from? If it’s written anywhere on this site, I will get it changed, because it is incorrect. Currents are not normally displayed, only the three powers are normally sent to emonCMS, and those ARE available separately. But if you specifically want to see the phase currents, then you can modify the emonTx sketch to send those as well as the three powers, and record and display them as you need. Normally, we display only power, because that is what most people are charged for by their supplier.
Again. that’s not quite true. When setting up the emonTx, you will be able to do at least part of the set-up and calibration in your “den”. For that, you will need a programmer (or a serial connection, but a programmer and a laptop is by far easier), and only the last stages of commissioning need to be done at the incoming cables.
What I think you will have, from what you have written, is:
At the switchboard where your incoming cables are: 3 c.t’s, one a.c. adapter, possibly one 5 V. d.c. USB adapter, and the emonTx. That will send the data by 433 MHz ISM band radio (not Wi-Fi) to
in your den, the RPi + RFM69Pi adapter (the emonBase).
In your other rooms, each has a temperature sensor sending data by Wi-Fi to the emonBase.
Somewhere else, a smartphone, tablet or computer on which you see the web pages generated by emonCMS, showing your power, temperatures, etc.
The reason for saying you might need a 5 V d.c. power supply to the emonTx is, if the a.c. voltage falls to far, it will stop working a reset itself when the voltage rises again, even though the interruption might only last for a fraction of a second.