THE PRACTICAL GUIDE TO OUTDOOR HIGH VOLTAGE INSULATORS
W L VOSLOO, R E MACEY, C de TOURREIL“The Practical Guide to Outdoor High Voltage Insulators” is intended to
provide an understanding of the factors which dictate the behaviour of
overhead line and substation insulators and to generate an appreciation of the
parameters which have a significant influence on their performance and life.
The Guide is aimed at utility staff and consulting engineers responsible for the
selection, specification, installation and maintenance of insulators. Students
of the subject and engineers-in-training should also benefit from its use.
The emphasis of the book is definitely on the “practical”, and simple
procedures, decision tables, flow charts and inspection sheets are included –
both in the text and on the accompanying CD – to assist those involved in the
design and operation of electrical transmission and distribution systems. The
structure of the book is described below.
Chapter 2 is especially useful to those who are new to the subject, of high
voltage insulators. It serves to define the terminology used and provide basic
information on the various insulator types and materials available. The main
physical attributes which determine the performance of insulators are also
addressed.
In Chapter 3 the electrical aspects to be considered when selecting
insulators, are discussed. It examines the various mechanisms of flashover
and the relationships between the probability of breakdown and the
dimensioning of an insulator.
It is impossible to select a suitable insulator for a particular application unless
the environment in which it is expected to operate is fully understood.
Chapter 4 describes the important ambient conditions that influence insulator
performance and provides techniques for their assessment. Methods to
interpret the climatic data and pollution levels measured, to define a “Site
Severity Class”, are described. This facilitates the selection of an appropriate
insulator for a given area.
With the wide variety of dielectric materials currently being used in the
manufacture of outdoor insul