Controlled Pyrolysis Oven Improves Repair Process

An important step in rewinding an AC Induction Motor is removal of the defective winding from the stator.  This is typically accomplished by utilizing an oven to raise the temperature of the stator to decompose the winding insulation. The motor winding wire is then easily removed from the stator laminations. Laminations are made from carbon steel and have been processed thru heat treatment and have an insulating coating applied to prevent eddy currents from moving from lamination to lamination.

Flolo utilizes a Controlled Pyrolysis cleaning furnace to remove the insulation such as cured varnish, epoxy and other organic materials from stators and rotors that need to be rewound. Ovens without temperature controls, as well as open flame stripping do not offer a controlled decomposing of the insulation in the way a Pyrolysis oven does. The temperature is controlled by utilizing a probe placed directly on the smallest part being processed to regulate the core temperature within 5 Degrees F of the set point. Should the temperature exceed the set point the controller turns on a water spray mist to cool the parts being processed and slow down the process. The set point is set for a temperature stipulated by the EASA/ANSI standard AR100.

All of these organic materials are removed without flame on the part and the byproducts that become airborne are incinerated in an afterburner to clean the air before exiting the stack. This meets the Illinois EPA clean air requirements.

This process has many positive effects including the prevention of heat damage to the insulation coating of the laminations as well as maintaining the design or pre-repair efficiency in the rewound motor. For more information on the positive effects of a Pyrolysis oven or to schedule a Flolo plant tour send an e-mail to or call 630-422-4914.