Electric Motor Rebuilding

THE PROBLEM:  Alternating current electric motors consist of a stationary housing (the stator), a rotor, and the end bells. The stator houses a wound copper wire coil, which is insulated by coating it with a varnish that dries to a hard consistency. Prior to rebuilding these motors, the copper winding has to be removed and the stator cleaned of any remaining insulating material.

In times past, rebuilders simply placed the stators in a metal container, soaked them with kerosene and set them on fire. The heat annealed the copper and "burned-off" the varnish and other insulation. With this procedure, the stators were often damaged and the smoke generated by burning them in the open was a serious environmental problem.

THE SOLUTION:  Pollution Control Products Co. developed the first fully contained “burn-off” oven to solve the problem of safely removing the varnish and insulation from electric motor stators by using convection heat to anneal the copper and remove the insulation. The Company was also the first to develop a furnace with a separate afterburner to control the smoke and odor generated in the cleaning process. The Controlled Pyrolysis® Furnace, with its automatic temperature control regulated by the temperature of the stator core, was designed to safely and economically strip electric motor stators without any damage to aluminum or “T” frames.

The patented Controlled Pyrolysis® process positively controls the charring of the insulation and the rate of emission of the smoke and other volatiles inside the furnace. The stators are heated to 650-800°F (371-427°C.) and the insulation, varnish, epoxy, paint etc. are removed by pyrolysis - the chemical breakdown of organic materials by the action of heat. Automatic control of temperatures with water injection eliminates any damage to parts. Stators come out clean and ready for rewinding with a minimum of preparation. This unique process allows the cleaning of any size stator with any insulation system…Random-Wound or Formed Coils, Vacuum Pressure Impregnated, Pour-On, Thick-Cast or Dip and Bake.

Using Controlled Pyrolysis® ovens has eliminated open burning, acids, strippers and solvents, and the inconvenient and often dangerous handling and disposal of spent stripping materials. Cost savings usually will pay for the furnace in a short time and continue to pay dividends year after year. The successful use of the PCPC Controlled Pyrolysis® oven by Electric Motor Rebuilders has been field-tested and proven in over 1300 installations around the world.