The EMI filters in common household devices are designed according to the EMI regulatory standards to filter conducted emissions (noise) ranging typically from 150 kHz to 30 MHz. The function of these filters is to provide a low impedance path for the noise to the Protective Earth (PE), and to suppress the high frequency voltage occurring between PE and Neutral (N). This paper studies the behavior of the EMI filter for supraharmonics (conducted emission between 2 kHz and 150 kHz) under realistic conditions. The increase in PE-N voltage and the summation of the supraharmonics in PE can cause the tripping of Residual Current Devices (RCD) in places like data center causing the loss of money and information if power back-up is not used.