scope:

This standard covers capacitance current switching requirements for ac high-voltage circuit breakers rated in accordance with methods given in American National Standard Rating Structure for A C High-Voltage Circuit Breakers, C37.04-1964, and listed in American National Standard Schedules of Preferred Ratings and Related Required Capabilities for A C High-Voltage Circuit Breakers, C37.06-1972.²

It is anticipated that the manufacturers of circuit breakers will expend efforts to meet the requirements of these new standards as soon as possible. However, it is recognized that this will require time for completion; users are cautioned to confer with the manufacturer as to whether a specific design meets these standards. Circuit breakers manufactured before the publication date of this standard may not meet its requirements; the manufacturer should be consulted concerning the capacitance current switching capabilities of these earlier designs.

Purpose

The purpose of this standard is to define the special terms used, establish a rating structure, a schedule of preferred ratings, and a test procedure for the switching of capacitance currents with ac high-voltage circuit breakers An application guide is being developed and will be published at a later date. This standard is intended as an addition to the American National Standards for ac high-voltage circuit breakers rated on a symmetrical basis and their supplements (see the Foreword of this standard for a complete list). It is planned eventually to incorporate its contents into these basic circuit breaker standards.

This standard specifically covers those sections of American National Standards C37.04-1964, C37.06-1971, and C37.09-1964 concerning capacitance switching, which in those standards are noted as being under study or development by various industry committees