It’s important to correctly use reclosing equipments to keep power systems running safely and steadily. Because of the adaptability of outlet circuits with 3/2 connection

triangle connection and double circuit-breakers

the reclosing mode must alter along with system running mode. This paper analyzes a refuse accident of a reclosing equipment with triangle connection in a 220 kV central substation

reveals the causes and relative problems

and moreover proposes some specific methods to prevent the similar accidents for grid safely running.