Polyester glass — Its use and factors governing its use in the 5 & 15 kV metal-clad switchgear

The progress and design of 5 and 15 kV metal clad switchgear can be directly connected with the introduction of new insulating materials. Without the broad spectrum of properties, both electrical and mechanical, presented to the Switchgear Industry throughout the 50´s and 60´s in both polyester glass and epoxy, we would have been hard pressed to meet the design requirements of the gear as it exists today. Polyester glass has been the chief contributor to these dynamic design changes not only because of its ability to meet the design requirements, both electrically and mechanically, but also because of the speed in which parts can be produced which reflects in the cost of the final part.