Now -a - days electrical trains have significance than the fuel trains like diesel and coal fuel does not produce emission as like other trains. So, in recent days faults and also increasing in the electric motors and components used in the electrical trains. We have so many methods to detect the faults. In this paper we are mainly explained about the techniques used to detect the faults in electric machines. The main faults are rotor bars, gear tooth surface, vibration caused in shaft, bogie wheel faults etc.