The T-H300 provides an accurate automatic or manual fault location for cable sheath faults. It utilises the DC resistance method in conjunction with an internal high voltage DC source. The device can be used in automatic mode, providing accurate fault location based on only entering the cable length, or manual mode can be used. The equipment also allows the measurement of insulation impedance.

The DC resistance method calculates the fault distance by measuring the DC resistance from the measuring point to the fault point.

It uses its internal DC power supply (negative polarity) to inject a current into the cable sheath and the earth, measure the DC voltage, and obtain the resistance between the measurement point and the fault point by dividing the voltage by the current. This is then divided by the result of a similar measurement on a healthy core, and the resulting ratio is multiplied by the cable length to give the distance to the fault.

Typical connection diagram

Connection diagram for insulation impedance test

Technical Data