Rupturing capacities of oil circuit breakers

This paper is really a series of more or less disconnected notes dealing with the question of rupturing capacity of oil breakers. It makes no attempt to go into the theory of circuit breaker design, and its main object is to open up a discussion regarding the advisability of using the term “Maximum Safe Rupturing Capacity” to describe the result obtained by the root-mean-square of the maximum peak of the current wave that occurs while the breaker is opening, multiplied by the root-mean-square of the open circuit voltage that occurs immediately after the breaker opens. Attention is called to the different ratings due to use of peak values and root-mean-square values of current voltage. It is recommended that an oil switch or an oil circuit breaker should be given a rating on the basis of maximum safe rupturing capacity that it can handle, and that a breaker after opening a short circuit up to its rating, should be immediately reclosable, and able to again open up a similar short circuit; breaker should open three successive short circuits before contacts need be repaired or oil replaced; these short circuits may be as close as two minutes apart.