Application of New Methods for Calculating Short-Circuit Duties and Power Circuit-Breaker Capabilities

The more salient points in the application of ac high-voltage circuit breakers according to new Standards C37.010 1964 and C37.5-1969 are outlined. The relationship between circuit-breaker rated interrupting and momentary capabilities and the corresponding calculated duties is defined. Areas of ambiguity, omissions, and controversy which exist in the standards are under review at the present time. The authors report some of these areas for information only.