Blowout coil

(electromagnetism) A coil that produces a magnetic field in an electrical switching device for the purpose of lengthening and extinguishing an electric arc formed as the contacts of the switching device part to interrupt the current.

A coil that produces a magnetic field in an electrical switching device for the purpose of lengthening and extinguishing an electric arc formed as the contacts of the switching device part to interrupt the current. The magnetic field produced by the coil is approximately perpendicular to the arc. The interaction between the arc and current and the magnetic field produces a force driving the arc in the direction perpendicular to both the magnetic flux and the arc current (see illustration).

Relation of directions of current, magnetic flux, and movement of arc in a blowout coil.