Transient is any instantaneous change in the state leading to a burst of energy for a limited time (very short). The causes can be both external and internal, with the aftermath being sequential and affecting the other parts too. Transient suppressors are used for removal of Power System transients. Lightning is one of the main cause of Electrical Transients in Power System. Transients can reach several thousand volts and can seriously damage equipment but, fortunately, protection is achieved easily and economically by the use of transient voltage surge suppressors.