Portable TDR Cable Fault Locator with Clamp Current Method and Acoustic Magnetic Synchronization

• Time Domain Reflectometry (TDR) technology for precise fault location
• Clamp current measurement method for accurate current analysis
• High-precision positioning of cable faults
• Reliable performance in various cable testing scenarios

Technical Specifications

Working Principle

Positioning Function
The AC220V mains power is rectified by full-wave rectifier to achieve excellent conversion, transforming it into a high-power special signal required for identification. This signal is applied to the cable to be located through the connecting wire. The "step voltage method" or "current method" can be used to accurately locate the cable fault.

Step Voltage Method

If a buried cable experiences a grounding fault, we can use the potential difference method to locate the fault point. The method involves applying a test voltage between the test point of the faulty cable and ground. This will create a distributed electric field concentric with the cable's entry point. Within this electric field, there is no potential difference between any points with the same radius, but a potential difference exists between any two points with different radii (as shown by points A and B in the diagram). Furthermore, when the distance between the two points is fixed, the potential difference is stronger the closer they are to the center.

Using this characteristic, we can move points A and B gradually closer to the center. When the fault point is exactly between points A and B, the potential difference becomes zero. If we continue moving past the fault point, the polarity of the potential difference will reverse. By moving back and forth in this way, the grounding point can be accurately determined.

Current Method

If a ground fault occurs in a tunnel cable, we can locate the fault point by observing the opposite current directions before and after the fault. This is done by applying a high-voltage pulse signal to the faulty cable to discharge the fault. At this point, currents of opposite polarity will be generated before and after the fault, but the current at the fault point will be minimal.

Using this characteristic, we can use a receiver clamp to determine the current direction before and after the fault. By clamping the receiver clamp onto the cable, the receiver box will indicate a direction. If we continue moving it past the fault point, the current polarity will reverse. By moving it back and forth in this way, we can accurately determine the ground fault point.