Grounded Fault Indicator for Overhead Network Based on 10 kV Low Resistance Grounded System

Based on low resistance grounded system of Shanghai urban district, a new grounded fault indicator for overhead network was put forward. Adopting compound mode of zero sequence transformer and indicator, zero sequence current break was reflected. And matching the relay protection grounded operation and line recloser, it was ensured after tripping operation because of line grounded fault that the fault indicator operates properly, reflects fault coverage and replaces automatically or manually. The indicator have merits of light weight, convenient installation, clear alarm, long useful time, low cost and free maintenance.