How to check for faults in buried cables

The following methods and steps can be taken to check for faults in buried cables:

1. Analyze the nature of wire faults and understand the types of faulty cables. Because different types of cable faults require different testing methods, for example, low resistance faults (such as open circuit, short circuit, etc.) and high resistance faults (such as leakage, flashover, etc.) require different testing methods. At the same time, it is important to understand the voltage rating and other relevant parameters of the cable in order to select the appropriate testing method.

2. Use HV4020 cable fault tester and other equipment for fault pre positioning. These devices can help determine the approximate location of the fault point, thereby narrowing down the search scope. For example, the low-voltage pulse method can be used to test the length of cables and calibrate the radio wave transmission speed of cables, which helps to determine the type of fault (such as high resistance or low resistance faults) and the specific situation of the cable.

3. Use a pathfinder or HS140 pipeline detector to detect the direction of buried cables. Before accurately locating the fault point, it is necessary to know the precise path of the cable. If the path is known, this step can be omitted.

4. Use a fixed-point instrument to accurately locate the fault point. After determining the path of the cable, devices such as fixed-point instruments can be used to accurately locate the fault point. This usually involves connecting high-voltage discharge equipment and determining the degree of voltage boost based on the nature and withstand voltage level of the cable. During the positioning process, it is important to distinguish between the discharge sound and interference sound at the fault point to ensure accurate positioning.

5. Verify the test results and repair the cable. After determining the location of the fault point, excavation verification should be carried out to confirm the accuracy of the fault point. Then, corresponding repair work should be carried out according to the cause of the fault, such as replacing cables, repairing insulation layers, or replacing joints.

During the entire inspection process, safety precautions should be taken, such as wearing appropriate protective equipment and ensuring good grounding of the equipment. At the same time, relevant operating procedures and standards should be followed to ensure the accuracy and reliability of the inspection.

The above steps for checking buried cable faults are for reference only, and the specific operation should be based on the actual situation. If encountering difficulties or uncertain situations, it is recommended to seek the help of professionals.