Effects of arcs in enclosures filled with SF6 and steps taken to restrict them in SF6 switchgear

For internal arc faults in metalclad SF6 switchgear the main parameters fault current, arc voltage, fault duration, enclosed volume and material of the enclosure are discussed in relation to test results. The effects in connection with pressure rise and melting through are stated, from which the requirements to be complied with by SF6 installations are derived. Measures to restrict the effects of arc faults are compared and a solution deduced which satisfies the requirements imposed.