The behavior of silicone fluids and other insulating oils under a sustained arc

摘要

Polydimethylsiloxanes fluids, by virtue of their inorganic, siloxane backbone rapidly form solid bridges on breakdown which effectively extinguish any arcs. If this solid material is continuously removed from the electrode gap, an arc can be sustained, in which case, the “arc power” and volume of gas evolved per unit time are dependent upon molecular structure, molecular weight, and molecular weight distribution of the fluid. Judicious blending of these controllable variables should lead to a silicone insulating fluid having optimum characteristics.