Shading coil


A shading coil or shading ring is a single turn of electrical conductor located in the face of the magnet assembly or armature. The main alternating magnetic flux induces currents in the Frager coil. So, these induced currents create an auxiliary magnetic flux. This auxiliary flux is out of phase from the main flux.
The property of property allows the armature sealed-in when the main flux falls to zero times / second with 50.
Without this shading ring, the armature would tend to open each time the main flux goes through zero and create noise, heat and mechanical damages on the magnet faces

Shaded-pole AC motors

A shaded pole motor is an AC single phase induction motor. The auxiliary winding, is composed of a copper ring, called a shading ring.
Shaded-pole motors are provided with a main winding connected to the single-phase electric supply. In addition, that kind of AC motors have a permanently short-circuited winding, known as a shading coil and located ahead of the main winding in the direction of rotation. This shading coil consists of one or more shorted turns. The shading coil allows to delay the establishment of magnetic flux in the region that it encircles and producing thereby a small component of rotating field at standstill.