The increasing demands on insulation

The advances in insulating materials in the past few years have been major indeed. Yet the users of electrical apparatus are continually imposing new demands on those who manufacture the products containing insulation and upon the technology of the materials themselves. Controls, motors and other devices are now becoming physically smaller with respect to the duties they must perform. The result is that frequently wire and other insulated materials must operate at much higher temperature than was required just a few years ago. In several industries the insulation systems of controls and motors are exposed to specific atmospheres differing in many respects from the more normal exposure to air. For example hermetic refrigeration motors operate in an atmosphere of the refrigerant gas used in the system. In addition they may be exposed for extended periods to liquified refrigerant.