The fault circuit indicator is an instrument for detecting short circuit and earth faults. This indicator is used in medium voltage radial networks with one input. In order to avoid serious failure happening in the distribution power network, especially in the network where lot of ring main unit with loadbreak switch were used, as a rule, the upper level system must trip within the set time when a short circuit or earth fault occurs in the low level. After dividing and breaking happens, the whole network subjected to the upper level will be powered off. The indicator can locate and indicate the fault position so that the operator can find and trip the fault section quickly according to the  alarm signal, which will save a lot of working time, shorten the time and range of power cut.

The sensors are used to detect the load current and earth current respectively. The trip level for earth fault and short circuit are adjusted by threshold level electronic. When the current exceeds the pre-adjusted threshold level, and impulse is sent to the reading instrument of evaluation. And then the respective LED is activated and starts to blink.

The equipment have the function of inrush restraint which avoids the wrong indication by the switching on/off operation.

Unit packing detail

-Fault circuit indicator

-Installation instruction sheet