How do I choose a proper approach for detecting ground fault currents (20 mA through 30A, 60Hz)? Let's say I have a zero sequence CT and calculate a burden resistor. I have a 12-bit ADC in the micro. I have seen different methods:

  1. A peak detector, like this one
  2. DC biasing like this
  3. Doing some FFT in the micro?

I want to avoid as much hardware as I can and leverage the microcontroller, even for filtering. Also, I don't think a fixed gain amplifier or burden resistor would cover this wide range of current with good resolution?

I'd appreciate your suggestions.

  • 1
    \$\begingroup\$ Use a GFCI (USA) or an RCD (UK)? \$\endgroup\$ – Andy aka Mar 3 '20 at 14:35

I dont have reputation so i could not able to comment. The most common way is using fuse.But the circuit stops working if fuse breakes .

Do you want to detect the false currents ? or do you want to detect and eliminate or suppress?

For ac circuits you can use bypass capacitors , it short circuits during high frequency.


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