Arc Length of Break Arcs Magnetically Blown-out at Arc Extinction

摘要

Silver electrical contacts are separated at constant speed and break arcs are generated in a DC300V-450V/10A resistive circuit. The transverse magnetic field of the permanent magnet is applied to the break arcs. The alumina pipes are put on the contacts, and the motion of break arcs is restricted. Dependences of the arc lengthening time and the arc length just before arc extinction L on the strength of the magnetic field and supply voltage are investigated. As a result, the arc lengthening time increases with increase of the supply voltage E. The arc lengthening time tends to decrease when the magnetic flux density B_x is increased. The arc length L increases with increase of the supply voltage E. The arc length L increases with decrease of the magnetic flux density B_x. The arc length L increases linearly with increase of arc lengthening time t_m when no re-ignitions occur.