A method for detecting a residual current flowing through an intelligent power strip (IPS) having at least one alternating current (AC) power outlet , the method comprising: obtaining current sensing information; performing an analog-to-digital conversion (ADC) of the current sensing information to obtain ADC samples; obtaining a time series collection of the ADC samples as residual and outlet current waveform samples; using a microcontroller to perform operations including: calculating a residual current (RC) RMS value for the obtained residual current waveform samples; calculating phase current from the aggregation of the outlet current waveform samples having the same phase; calculating Pearson's correlation coefficients for variables relating to the residual current waveform samples and to the phase current; calculating Pearson's correlation coefficients for the variables relating to residual current waveform samples and individual outlet current waveform samples from each AC power outlet; determining the phase having a maximum positive Pearson's correlation when the residual current RMS value is greater than a predetermined residual current RMS threshold; and determining an individual one of the AC power outlets having the maximum positive Pearson's correlation when the residual current RMS value is greater than the predetermined RMS threshold. obtaining current sensing information; performing an analog-to-digital conversion (ADC) of the current sensing information to obtain ADC samples; obtaining a time series collection of the ADC samples as residual and outlet current waveform samples; using a microcontroller to perform operations including: calculating a residual current (RC) RMS value for the obtained residual current waveform samples; calculating phase current from the aggregation of the outlet current waveform samples having the same phase; calculating Pearson's correlation coefficients for variables relating to the residual current waveform samples and to the phase current; calculating Pearson's correlation coefficients for the variables relating to residual current waveform samples and individual outlet current waveform samples from each AC power outlet; determining the phase having a maximum positive Pearson's correlation when the residual current RMS value is greater than a predetermined residual current RMS threshold; and determining an individual one of the AC power outlets having the maximum positive Pearson's correlation when the residual current RMS value is greater than the predetermined RMS threshold. calculating a residual current (RC) RMS value for the obtained residual current waveform samples; calculating phase current from the aggregation of the outlet current waveform samples having the same phase; calculating Pearson's correlation coefficients for variables relating to the residual current waveform samples and to the phase current; calculating Pearson's correlation coefficients for the variables relating to residual current waveform samples and individual outlet current waveform samples from each AC power outlet; determining the phase having a maximum positive Pearson's correlation when the residual current RMS value is greater than a predetermined residual current RMS threshold; and determining an individual one of the AC power outlets having the maximum positive Pearson's correlation when the residual current RMS value is greater than the predetermined RMS threshold. <EOS>