A cable fault locator is a diagnostic tool designed to detect and accurately locate damage in electrical or fiber—optic cables. Damage can be both mechanical (fractures, tears, insulation wear) and electrical (high resistance, short circuit, insulation breakdown).
Basic methods and principles of operation:
- Pulse Reflectometry (TDR)
The device sends a short pulse along the cable. If there is an impedance change in the path (for example, an interruption), part of the signal is reflected back. The return time helps determine the distance to the damage. Suitable for accurate measurement of open and short circuits
- Surge generator (“thumper”)
Creates a powerful pulse of high voltage, causing a breakdown of air at the site of the defect. This location can be detected using an acoustic or electromagnetic sensor. It is effective for high-resistance or non-permanent faults.
- Acoustic—magnetic tracking
Combines an acoustic sensor and a magnetometer, detecting the signal from the arc at the breakdown point. Especially useful for underground and armored cables. Tracing and labeling method A signal generator and receiver are used to find the location of the cable underground, before searching for defects. This is important for laying the route and preventing accidental damage.
Application examples
- Maintenance of underground power cables in urban networks
- Diagnostics of damages in communication lines and Internet cables
- Checking cables before commissioning or after accidents
