Analisis Hasil Pengujian Tahanan Isolasi dan Keserempakan Pemutus Tenaga 150 kV Bay Palur 1 dan Palur 2 Gardu Induk Gondangrejo

In an electric power system, the protection system aims to secure electrical and human equipment located in the vicinity of interference (short circuit). One of the equipment included in the protection system is a Power Breaker (PMT). The main function of PMT is as a tool to open or close an electrical circuit under load conditions, and can open or close when there is a fault current (short circuit) on a network or other equipment. This study aims to find out how the reliability and feasibility of Bay Palur 1 power breaker and Palur 2 in Gondangrejo substation after biennial maintenance. PMT maintenance is carried out by testing the isolation resistance and the simultaneous PMT contact test. The study was conducted by looking for literature studies and then taking data at the Gondangrejo substation, then the data obtained were analyzed according to existing literature studies. From the analysis of the test results it can be seen that the Palur 1 and Palur 2 bay breakers at the Gondangrejo substation are still feasible and working well. The insulation resistance values at the Palur 1 and 2 bay power breakers have varying values in each maintenance period. The value of inter-phase isolation resistance also varies. The value of the smallest isolation capability in the last 2 maintenance periods is 5,230 MΩ / kV in Palur 1 bay while the smallest capability in Palur 2 bay is 14,940 MΩ / kV, this value still meets the standard of ≥ 1 MΩ / kV. The results of testing the PMT contact randomness vary in each maintenance period. Working time for individual contacts is still within the permit ed limit of under 120 milliseconds. The highest intermittent working time difference (randomness) when open PMT is 1.2 milliseconds. This value occurs in the PMT bay Palur 1 contact frequency in 2015 and 2017 and all the similarity values meet the standard of