Investigation of Silicone Insulation on High-Temperature Railway Motor

Thermal aging and humidification tests are reported on a silicone insulated railway motor. This included 1,675 hours at a temperature of 285 degrees centigrade with 46 cycles of severe humidification. Loss of initial moisture resistance was observed but no operating failure occurred. No change occurred in the heat dissipating characteristics of the machine. Finally, the motor was dismantled and the insulation examined in detail. Thermal aging data are interpreted.