Ceramic and glass station post insulators

1.1
This Standard specifies the electrical, mechanical, dimensional characteristics, test methods, and acceptance criteria for solid-core and cavity core ceramic and glass type station post insulators for outdoor service in electrical installations or equipment operating with a rated voltage greater than 1000 V and a rated frequency not greater than 100 Hz.

Note: Hollow core insulators are not part of this Standard.

1.2
This Standard covers insulators intended primarily for use as support or operating elements in switching equipment, or as bus bar or other equipment supports in station.

Note: The electrical and mechanical characteristics for direct current insulators are similar to the comparable characteristics for alternating current insulators. However, due to the unidirectional voltage stress, special attention needs to be paid to the pollution susceptibility and to the location of insulators in a direct current scheme.

1.3
In this Standard, shall is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; should is used to express a recommendation or that which is advised but not required; and may is used to express an option or that which is permissible within the limits of the Standard.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.

1.4
The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.