We are reaching the testing phase of our device but there are still a few doubts related to isolation and ground references of the ADE7953 board.
1) To prevent short circuits when testing (Ex: Shorting a Oscilloscope negative probe) we are considering introducing a Isolation Transformer with a 1:1 Ratio for the voltage channel. Is this a good option,even if there is a very small distortion on the sinusoidal wave?
The current wave is measured with a magnetic sensor, so it's already isolated from mains power.This means that we whole circuit is isolated from mains power lines.
2) We are powering our circuit with a lab PSU. Considering that we implement the previous method then the PSU Ground reference is going to be our GND and not the neutral line.
Can we implement this tactics considering that the applications notes all recommend connecting the neutral line to GND.
3) According to AN639 the current sensor circuit should be connected to Digital GND, considering that we are using amplifiers and the high sensitivity of our sensor, isn't there going to be a lot of noise created by the others components connected to this ground plains(ex:crystal oscillator circuit).
An Isolation transformer if put in the right place will work fine. Line voltage is hazardous. If you are not familiar with using an Isolation transformer Please find someone local to help.