A comparison of contact erosion for two types arcing contact of SF6 circuit breakers in making process

The paper presents the results of making tests of arcing contact made from copper-tungsten (Cu-W) composites containing different contents of tungsten: 80% and 85%. The Cu-W arcing contacts are tested in a SF6 circuit breaker under the condition that the making velocity is 7m/s and the current peak is 18kA. The arcing time of every making test is measured. The electrical properties of the contacts are tested every 20 making operations and the mass loss is investigated after 100 operations. It is determined that the two types of Cu-W contacts have different electrical properties, in other words, their efficacy can be determined for the making as arcing contacts for an SF6 circuit breaker.