The purpose of this investigation was to determine if generator stator bars/coils with Class F insulation have self-extinguishing behavior. Specimens included samples prepared from both VPI and resin rich manufacturing processes with either a taped or painted stress control treatments. Specimens were selected from new, spare, and used specimens subjected to TCT/VET, as well as specimens from a generator removed from service. Testing examined the effects from an electrical arc, an ejected plasma stream, and a flame source, as well as material flammability testing measuring heat release rate using an oxygen consumption calorimeter. Two generator failures were used as control cases and compared with results obtained from laboratory testing.
Stator Winding, Electrical Arc, Fire Behavior, Stator Fault, Epoxy Insulation, Flammability Testing.