Cost effective motor surge capability

Using surge capacitors to protect medium voltage induction motor windings from steep-fronted power surges has long been an accepted industry practice. Claims have been made that motor reliability would be improved without the use of surge capacitors if added inter-turn insulation were incorporated within the motor winding. This paper explores the surge withstand ability of motors and the surge standards that have emerged. It presents a survey of industry practices, and studies related to current motor applications and provides the motor user with an economic evaluation to arrive at a cost effective selection of motors with or without external surge protection