ARC VOLTAGE FOR ARCING FAULTS ON 25(28)-KV CABLES AND SPLICES

Hazards to people and property due to arcing faults on medium-voltage underground cables and splices are related to the arc power dissipated in the environment by the arc. However, if the fault current may be a ccurately predicted from known circuit parameters, the arc voltage nee ded to evaluate the arc's power has no analytical expression due to th e fact that the arc resistance is non-linear. On the other hand, the a rc voltage is also strongly dependent on the Inherent physical propert ies of the faulted equipment, so that in order to establish the arc vo ltage value and shape developed by different currently used types of e quipment, a series of staged tests was performed at IREQ's high-power laboratory and other available data were collected. The results obtain ed prove that for arc power calculation purposes the arc. voltage curv e may be considered flat-topped and of constant amplitude specific to the type of faulted equipment.