Abstract-This paper proposes an improved scheme of fault detection and classification for multi-terminal transmission lines using discrete wavelet transform (DWT). The proposed scheme can correctly used to detect and classify the faults. The proposed scheme is dependent on line current data only. The proposed scheme is derived in the spectral domain and is based on the application of the DWT. The proposed scheme uses an adaptive threshold level for detect and classify the faults. The ATP/EMTP program is used to evaluate the presented approach. In addition, the nuclear power plants planned to be integrated with the Egypt electric network in 2026, so the presented approach is considered the installation of El Dabaa nuclear power plant. The presented approach achieves accurate results under numerous and enhanced fault detection and classification methodologies. The proposed methodologies have been applied correctly and verified a good contribution in detection and classification of electrical network faults.