Breaking arc in several liquid environments with light-duty application

The aim of this work is to study breaking arc phenomena in several liquid environments with light-duty application. The switching tests by using an inductive circuit (load inductance=20 mH, load current=0.5/spl sim/4A) were performed. The steady arc is observed in air under this test condition. The tests were carried out for silver, palladium contacts in several kinds of dielectric liquids such as distilled water, methanol and n-hexane. It was found that arc discharge types were affected by the dielectric constant of liquids as well as the load current. In liquids which have low dielectric constant (n-hexane), the steady arc occurred like in air. On the other hand, in liquids which have high dielectric constant (distilled water and methanol), the steady arc occurred in higher load current ranges, while the showering arc occurred in low load current ranges. Furthermore in this paper, the contact surface and contact resistance are described under the steady and showering arc occurrence conditions.