I am exploring options to improve the interrupting rating of a particular circuit breaker in an ungrounded 125VDC system. The breaker in question has an interrupting rating of 10000A at 125VDC. The breaker has 3 poles, but only 2 poles are currently being utilized (1 pole for the positive leg...
For a DC fault involving multiple current sources and a common branch, equation 50 of IEC 61660-1 describes a correction factor to be used in determining the short circuit current delivered by a source to the fault location. For source j, the correction factor is given as
?_j = R_resj * (R_ij...
