The LV FPI from Bowdens

The LV-FPI helps locate LV cable faults by tracing the path down which a fault current flows.

There are six sensors in a standard set, and they record the peak current that has been detected flowing down the buried cable over which they are placed. The sensors measure the magnetic field generated by the fault current. 

This fault current decreases as the sensor's distance from the source increases, however the sensor readings drop dramatically on the other side of any fault in the cable. By placing the sensors on different legs of a branched cable or down a straight cable then conditioning the fault and comparing readings it is possible to quickly locate cable faults without the need for excavation.