Hi Hmani,
I got the ADE7878 working.
I think the problem is with the ground connection. I got a new ADE7878 IC and dead bug soldered it on a prototype board. Now everything works fine. There was nothing wrong with the crystals.
I have a old relay tester which can supply variable voltages and current values. I supplied AC voltage and current and got the correct reading and got them calibrated.
I didnt isolate the i2c connection between micro controller and the ADE7878 and they both runs with single power supply.
So when I connect to AC mains three phase system and connect the Neutral line of the AC to AGND of the ADE7878 the system doesnt show any value.
In my system phase voltages are supplied through anti aliasing filter and the neutral is connected to AGND. And VN of the ADE7878 is connected to GND through a 1k resister.
Is there anything wrong with my connections?
Thank You
Bhanuka