Abstract: An alternating current electromagnet with a magnetic core assembly is provided with a unique design for a sideplate. The sideplate has a slot with a lateral opening. In assembling the sideplate onto the side of the magnetic core, the slot receives a shading coil. A portion of the sideplate forming the slot extends across a channel formed in a pole face of the core to lock the shading coil into the channel along the sides of the core. The sideplate is formed in a C-configuration and interconnects two L-shape cores arranged in a C-configuration with a gap existing between the confronting faces of the lower legs of the cores.