A selection ground relaying apparatus rapidly can correspond to the event occurrence by indicating the location information of the zero-phase sequence voltage and zero-phase sequence current in real time. The image transformer(GPT) is installed at the distribution line and detects the zero-phase sequence voltage. The zero-phase current transformer(ZCT) is installed at the distribution line and detects the zero-phase sequence current. By using the zero-phase sequence voltage and zero-phase sequence current, the reference setting part is set up. The display unit displays the zero-phase sequence voltage and the detected zero-phase sequence current. Controller determines whether the location information which is calculated by using the zero-phase sequence current and the location information are included in the reference area.
