Grading Protection – Fault current devices discrimination
Dr. Brown of Fraser George and Associates, is presently helping in a matter concerning an explosion in a 33/11 KV substation where inherent electrical fault current protection devices have failed, provoking a study of the grading protection, i.e. fault current device discrimination of the substation electrical network. A grading protection scheme is the consecutive time/current settings of fault protection devices such as circuit breakers fuses etc., so that in the event of a