When short circuit fault or earth fault occurs, fault indicators in front of the fault point will flash or turn flag to indicate the fault, the indicators behind the fault point will not indicate the fault. The operator can identify the fault area (between the last flashed indicator and the first non-flashed indicator) by following the flashed indicators. It can help operator to find out the fault point quickly.
The Di/Dt principle is used for fault determination and indication. When fault occurs, the current flow in the line will increase suddenly, the internal magnetic field will change, and the fault indicator will determine the fault based on surge value and duration of the short circuit current.
CREAT is the first company to detect the earth fault with signal injection method by assistance of a device called signal source, and the earth fault accuracy is improved greatly after using the signal source.
The fault indicator is designed and tested as per IEEE 495-2007 international standard.
Voltage: (6-10)kV
Current: (0-630)A
Suitable conductor diameter: (8-41)mm
Line minimum load current: 8A
Short circuit fault detection sensitivity: Automatically adapt to the load current and the setting value of substation outlet protection (Quick break/over current is greater than 150A, delay time is less than 3s, and the coincidence interval is greater than 0.5s)
Number of actions: not less than 4000 times
Short-term current tolerance: Effective value 20Ka/2s and the peak value 50KA/0.3s
Service life: 8 yrs