Archived Forum

I may be mis-reading your schematic, but it looks like you've tied your RPi GND to grid neutral?  If that's true, the whole system, including the RPi needs to be considered potentially live.

[EDIT]  P.S. Some of those voltage phase traces look very close together for signals that have 415V between them.

It looks to me as if your design is very dangerous if not illegal within the EU. You need to consider what happens if the neutral becomes disconnected between the unit and the supply. If that happens, the entire unit and anything and everything connected to it could become live to the full line voltage.

In broad terms, to make your unit safe, you need a totally separate power supply for the metering IC, you need to add optical or transformer isolation in all the signal lines between it and the rest of the circuit, and that isolation needs to be good to the full test voltage, with the correct tracking distances between the high voltage and low voltage sides. And the whole high voltage side needs to enclosed in an earthed metal box or double-insulated.

RobP with his GIVMon has very clearly explained the difficulties in making a SAFE means of monitoring mains voltages.

Correct, its not safe and its was not aimed to be in version 1.0

I don't claim to comply with any rules or regulation, nor do I sell this product to anyone.

Do not build the this in version 1.0 if you don't understand the risks.

Wait for updates, as version 1.0 is just a quick and dirty to get running with the software.

My goal now is not to comply with any safety regulations or discussion about safety or rules.

I want to see how good the ADE7878A is at measuring power and if it will be in harmony with my regular (from the power-company) meter in measuring power consumption. I also want to have this capability to load balance between phases and delay loads to avoid peaks.

If you want this isolated I can fix that, but I will  not do it if no one wont use it.

Me personally don't need it. If others want to build this, fine I fix that.

I want some discussion bout the capabilities of the ADE7878 vs other home-brews.

Thanks

/Nicholas

Here's the wiki link: http://wiki.openenergymonitor.org/index.php?title=ADE7878A_rpi

Thanks for adding. 

I'm interested to see how this develops, have you built a prototype yet? I have not got experiance with the ADE7878A. What made you choose this chip over others?

Thanks Glyn.

Happy to share if it can be of use for someone else.

PCB is under manufacturing, maybe 1-2 weeks away.

made by : https://oshpark.com/  (first try with this vendor)

Parts are in transit to my home.

ADE7878A chosen based on googling.

Part is readily available from mouser and digikey. Good documentation and app-note.

I wanted a side-kick chip for the PI that is dedicated and specialized on accurate poly phase power metering.

I did not want another CPU.

I already use pi for different measurements that goes into sql database and then reports/actions are generated from the database by other pi/computers. Also the PI has WLAN (over USB).

It will be an addition to my echo-system of measurement and control.

/Nicholas

Design was removed from forum by request of moderators.

Communication with device established.

8 / 16 / 32 read and writes functions created.

Init of device started just now.

C++ files available.

ADE7878A is an c++ object / class.

Compiled as shared library,  .so file can be shared.

Works like a charm now

3 phase.

accurate.

Works like a charm now

Maybe, but the design has serious safety concerns as per the posts above, and therefore it is not supported or endorsed by this forum.

Paul - Moderator