Some evaluations of hermetic motor insulation systems

Hermetic motors used in refrigerators, room air-conditioners etc. which are operated with Refrigerant 12 or Refrigerant 22 and refrigeration oil, are required to have insulating materials whose characteristics are stable in these atmospheres. Generally, in Japan, refrigerant resistance of insulating materials is evaluated according to the tests prescribed in the Japanese Industrial Standard (JIS C3003-1969), Ref. (1), which include extraction, blister characteristics, etc. However, it has been difficult to establish correlations between these results and the performance of actual machines.