Evaluation of induction warming stator cores for coil removal

Past methods for warming stators for mechanical coil removal included: gas flame; oven warming; oil bath; and, electric heaters. Independent studies including the Canadian Electrical Association´s “Evaluation of Electric Motor Repair Procedures,” in 1995, and the US Department of the Navy (NAVSEA Motor Repair Manual), identified that these methods have no measurable impact on the core and environment. An induction warming method has been introduced with the intention to improve coil removal times and environmental impact. The purpose of this paper is to compare gas flame to inductive warming and review warming times, post-stripped core condition, and impact on the stator core on integral horsepower machines.