The Dielectric Power of Mixed Gas Insulation of SF₆-CO₂ and SF₆-N₂

Some high-voltage equipment uses gas as an insulating or cooling medium in its operation, like a power breaker that uses gas to extinguish its arc. In its performance, the dielectric strength of the gas material must meet the standards so that the circuit breaker can operate properly. One of the insulating gases with excellent dielectric strength is sulfur hexafluoride (SF6) gas, but it is known that its continuous and excessive use can damage the environment. Because of this problem, many studies have been carried out by mixing SF6 with other insulating gases such as Carbon dioxide (CO2) and Nitrogen (N2) to find safe gases for the environment but still prioritize the dielectric strength the gas. This paper researches a gas mixture of SF6 with CO2 and SF6 with N2, which aims to determine the dielectric strength of the gas mixture after experiencing electricity penetration many times. The test was carried out using spherical electrodes with a diameter of 5 cm with an electric breakdown of 40 times at a pressure of 1 bar. The study result was found that the number of electrical breakdowns experienced by each gas mixture causes the dielectric strength of the gas to decrease.