NEMA HV 2:2014

INTRODUCTION High voltage line insulators of essentially the same basic designs as those made today have been providing reliable service for many years. An even greater level of reliability can be attained by recognizing that insulators are both structural members and electrical apparatus and it is equally important that they be properly handled, stored, installed, and maintained. Suspension and post type insulators for electric power overhead lines are described and defined in the voluntary C29 series of American National Standards [1-9]. The sole purpose of these product standards is to define dimensions and tests as required to ensure the interchangeability in service of one manufacturer's insulator with that of another for the same type and class insulator. Conformance of a given insulator to the mechanical and electrical requirements of a particular standard, when subjected to tests as described in the standard, is intended to assist users in selecting their insulators. High voltage insulators are but one component of overhead electric lines and users are assumed competent in integrating them into their systems. Necessarily, not all conditions can be anticipated in a general discussion and the proper use of information offered here is the responsibility of the user.