The use of ZnO arrester for electrical equipment Lightning surge protection has been worldwidely spread since the last two decades. Many researches paid attention to the performance of the ZnO arrester. Many kind of ZnO arrester tests were carried out. One kind of test that needs to be done is an impulse current testing using 8/20 microseconds impulse waveshape of 5000 A and of 10000 A amplitudes. As has been known that the life time of ZnO arrester installed at some electrical system is determined by the number of lightning that really strike and result in large amplitude of impulse current flowing through the arrester. This research shows the design of impulse current parameters and their effects in producing impulse current waveshape toward an impulse current of 8/20 microseconds using EMTP (Electromagnetic Transient Program). It was found that by increasing the inductance of the circuit making a longer time to reach the amplitude of the impulse. While increasing the capacitance results in the increase of the impulse current amplitude. The resistance can control the tail time of the impulse current. By means of EMTP, it can be designed the impulse current waveshape of any kind. Therefore, before the impulse current wave physical construction is made, the EMTP was used to determine the impulse current parameters. The result of varying one parameter related to the size, the kind, and other thing that we would like to have a look. Finally, the impulse current circuit can be constructed as required by the arrester testing methode.
