Heater plate design for voltage endurance testing

IEEE Std. 1043-1989 "Recommended Practice for Voltage Endurance of Form-Wound Bar and Coils" does not provide a specific design for slot heater plates. There are, however, established guidelines to assure consistent test results between facilities. Common practice has been to apply several pairs of short plates to each slot section to obtain the desired test temperature. This paper presents several problems inherent with short, uninsulated heater plates and provides the results of an investigation into energy-efficient slot length heaters. Advantages of insulated low-power slot heaters are enumerated.