AC Contactor with Shading Coil

Application ID: 102771


An AC contactor is a particular type of magnetic switch device, which is activated by a primary coil fed by an alternating current. Unlike DC switches, such devices can suffer from a tendency to reopen when the AC current crosses zero. The addition of a shading coil that supports retarded induced currents with respect to those of the feeding coil makes it possible to always have a nonzero pulling force, thus providing a more stable closure.

This example studies the closing dynamics of an AC contactor and the consequent establishing of a mechanical contact. The changing distance between the moving and stationary parts of the device has an influence on the distribution of the magnetic field. This effect is accounted for using a moving mesh in the surrounding air. The model is set up using the Magnetomechanics multiphysics interface.

This model example illustrates applications of this type that would nominally be built using the following products: