Electrical Endurance of DC Switching Devices

The article focuses on the electrical endurance testing of direct current switching devices, such as high speed circuit breakers, switch disconnectors and contactors. It presents the normative requirements for these tests and provides sample results obtained during testing conducted in the electrical laboratory of the Department of Electrical Power Engineering at the Railway Research Institute. The most commonly tested switching devices have nominal voltages of 900, 1800, and 3600 V DC, with nominal currents of up to 6.5 kA. The article also discusses phenomena and hazards that may occur during electrical endurance testing.