IEEE C37.012-1979

This application guide for capacitance current switching applies to ac high-voltage circuit breakers rated in accordance with ANSI/IEEE C37.04-1979, Rating Structure for AC High-Voltage Circuit Breakers, and listed in ANSI C37.06-1979 , Schedules of Preferred Ratings and Related Required Capabilities for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis. It is intended to supplement ANSI/IEEE C37.010-1979, Application Guide for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis. Circuit breakers rated and manufactured to meet other standards should be applied in accordance with application procedures adapted to their specific ratings.

This guide is intended for general use in the application of circuit breakers for capacitance current switching. Familiarity with other American National Standards applying to circuit breakers is assumed, and provisions of those standards are indicated herein only when necessary for clarity in describing application requirements.

New IEEE Standard - Superseded. AC high-voltage circuit breakers rated in accordance with ANSI/IEEE C37.04-1979, Rating Structure for AC High-Voltage Circuit Breakers, and listed in ANSI C37.06-1979, Schedules of Preferred Ratings and Related Required Capabilities for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis, are covered. Considerations for capacitance-current switching applications include maximum voltage for application, frequency, capacitance current, interrupting time, transient overvoltage, open-wire transmission lines, capacitor banks, cables, switching through transformers, unusual circuits, effect of load, effect of reclosing, resistor thermal limitations, and the current pause method. Capacitance currents and recovery voltages under fault conditions are also addressed.