The design of circuit breakers is mainly based on experience rather than precise science. Empirical formulae can be used to determine dimensions of certain general types and the breaking capacity rating. Further developments will rely on new research of a scientific as well as a practical nature. This book, by a woman who has contributed to the development of electrical arc control in circuit breakers, provides new insight into arc root motion in the contact region. It combines new results from pressure, spectral and optical data. This is the first time that the influences of magnetics, gas dynamics, thermal energy, mass flow, gas composition, arc chamber venting, contact material, arc chamber material, short circuit current, polarity, contact opening velocity and the gap behind the moving contact on the arc control have been presented. There are 8 chapters give a general account of arc root motion, experimental facilities, results from modelling and experiments. The last two chapters discuss the significance of the results and effects of the parameters. Engineers and professionals will profit immensely from this outstanding volume. The 2dn Edition includes the new innovation data, discussion and analysis the insight of the arc spectrum, electron energy, mass and temperature rise for each chemical element for materials of the arc chamber: Polycarbonate and ceramic, contact materials: Ag/C step and Cu punch, and contact opening velocity: 1 m/s and 10 m/s.
