International Journal of Academic Engineering Research (IJAER)   Year: 2023 | Volume: 7 | Issue: 5 | Page No.: 2-6 Testing of the 150 Kv Circuit Breaker Based on The Results of Isolation Resistance and Contact Resistance Tests Download PDF Enda Wista Sinuraya, Yuli Christyono , Bambang Winardi, Agung Nugroho Abstract: Electricity is one of the most important energies for the sustainability of human life. In Indonesia, electricity is managed by the company PT PLN (Persero), which is the provider and supplier of electricity to all regions in Indonesia. One of the stages in the distribution of electricity is the transmission system at the main substation. Transmission at the main substation is a useful stage for lowering the voltage of electricity and as a means of connecting the generator system and distribution system before it is supplied to consumers. In the transmission system, regular maintenance of equipment at the main substation is necessary. One vital piece of equipment is the Circuit Breaker (CB), which functions to disconnect load currents both in normal and abnormal conditions to protect other equipment from damage. Therefore, the reliability of the CB must always be maintained. Examples of tests that are conducted to ensure the reliability of the CB include contact resistance testing and insulation resistance testing. Contact resistance and insulation resistance testing are usually conducted annually.