Materials and Process Selection for Engineering Design, 3rd Edition

316 Materials and Process Selection for Engineering Design

Analysis

Rigid requirements in this case are exibility, or ductility, of the insulating

material and operating temperature. The requirement for ductility eliminates

all ceramic insulating materials, and the operating temperature eliminates some

plastics such as LDPE.

The next step is to analyze the electrical and physical design requirements.

They are as follows:

1. Dielectric strength, which is related to the breakdown voltage, is a

lower-limit property in this case. Owing to space limitations, the dielec-

tric strength should be more than 10,000 V/mm.

2. Insulating resistance depends on both the resistivity of the material and

the geometry of the insulator; it is the lower-limit proper ...