T-KF200 Cable Sheath Fault Pinpointer

The T-KF200 can pinpoint the location of a fault on a buried power cable sheath using the Pool of Potential method. The unit can receive a signal generated by the T-100C voltage source. If a cable is not buried in the ground, the T-KF200 can also determine the direction of the fault using its current sensing accessory, then find its exact position through sectionalising (i.e. determining the current direction at different access points on the cable, until the faulty section is identified).

When a cable is buried, it can be considered to be surrounded by the earth at all points along its length but due to its insulation, the fault is the one point of galvanic contact between the sheath and the earth. If a voltage is applied between the metallic sheath and the earth it produces currents which expand in to the ground. An idealised plan view of the fault point indicates the concentric points of equipotential (the pool of potential), such that the voltages at A, B, C and D are equal but A -0 is positive, whereas 0 – C is negative. It should be noted that in a real situation the voltage rise on the source side is more gradual and so the equipotential lines will not be circular.

The T-KF200 uses this phenomenon to pinpoint the sheath fault. The faulty cable is disconnected from the supply and the earth, the T-100C is connected to its metallic sheath and a voltage applied. The spikes are inserted in the ground as far apart as possible and the polarity of the reading on the T-KF200 is noted. The test is repeated at regular intervals along the cable path, until a change in the polarity is noted. The null point between the peaks of polarity will represent the position of the fault.

The T-KF200 can pinpoint the location of a fault on a buried power cable sheath using the Pool of Potential method. The unit can receive a signal generated by the T-100C voltage source.

If a cable is not buried in the ground, the T-KF200 can also determine the direction of the fault using its current sensing accessory, then find its exact position through sectionalising (i.e. determining the current direction at different access points on the cable, until the faulty section is identified)

Features:

  • High sensitivity and large response range.
  • Automatic zero adjustment to offset the influence of ground potential changes.
  • The fault point can be segmented by measuring the resistive current in the faulty cable with a current sensor.
  • High-performance rechargeable lithium battery, continuous operation for more than 15 hours from fully charged, with low charge warning and automatic shutdown.
  • Rugged housing, lightweight and portable.

Technical data

Signal receiving modes

Voltage Signal, probe input
Current signal, sensor input
Display functions Signal waveform
Direction of fault point
Battery level etc.
Input resistance 0 – 2000Ω
Input sensitivity 100µV or 5mA
Maximum probe input signal voltage 300V
Accuracy ±0.2m
Signal receiving mode Ground spikes
  Current sensor
  High-voltage probe
Power supply 3.7V, 6.8AH rechargeable battery
Environmental conditions Temperature: -10-40 °C; humidity 10-90% RH; altitude <4500 m
Dimensions and weight Main unit 220mm × 125mm × 55mm, 0.9kg
 

Probe Φ75 × 400mm, 0.31kg

Our products:
Distribution Automation – PZG PZK-56 PZK-560K PZK-560Z
Power Utility – FTR-100 T-GPS XC-2100E 
Switched Reluctance Motor – SRM/SRD