A power cable fault tester is a professional instrument used to detect and locate power cable faults. In the field cable fault test, the use of a power cable fault tester needs to follow a certain test method to ensure the accuracy and reliability of the test results.
1. Preparation before the test.
Before conducting a cable fault test in the field, the following preparations need to be made:
1.Understand cable faults: Understand the model, specification, laying method, operation status and other information of the cable in order to better select test methods and instruments.
2.Determine the test plan: According to the actual situation of the cable, formulate a suitable test plan, including test steps, test point selection, safety measures, etc.
3.Prepare test instruments and tools: According to the test plan, prepare the required test instruments and tools, such as power cable fault tester, multimeter, insulation resistance meter, etc.
4.Ensure safety: Before the test, the site should be safe, and necessary safety measures should be taken, such as disconnecting the relevant equipment at both ends of the cable, setting up safety warning signs, etc.
2. On-site cable fault test method.
The field cable fault test method mainly includes the following steps:
1.Preliminary test of fault location.
In the preliminary test of fault location, the cable is first pressurized by DC using a fault tester, and the location of the fault point is determined by measuring the current wave signal. Then, based on the waveform and propagation velocity of the traveling wave signal, the approximate location of the fault point is calculated. At the same time, auxiliary methods such as sonometry can be used to further determine the location of the fault point.
2.Precise positioning test.
In the precision positioning test, a fault tester is used to pressurize the cable with a pulse signal, and the precise location of the fault point is determined by measuring the reflection and propagation time of the pulse signal. At the same time, auxiliary methods such as sonometry can be used to further verify and confirm the location of the fault point.
3.Judgment of the nature of the fault.
After determining the location of the fault point, it is necessary to judge the nature of the fault. The nature of the fault can be judged by observing the appearance of the fault point and measuring the insulation resistance. For example, if there is a significant burn mark or breakage at the fault point, it may be due to a fault caused by an overload or short circuit; If the insulation resistance is very small, it may be due to the failure caused by aging insulation or moisture, etc.
4.Fix the glitch.
According to the results of the judgment of the nature of the fault, take corresponding measures to repair the fault. For example, if the fault is due to overload, a larger capacity cable can be replaced or the capacity of the power supply equipment can be increased; If the fault is caused by aging insulation, the insulation can be replaced or the insulation protection measures can be strengthened.
5.Documentation and analysis of test results.
After completing the field cable fault test, the test results should be recorded and analyzed. The record content includes information such as test time, tester, cable information, fault type, fault location, etc. At the same time, the test results should be analyzed, and lessons should be summarized to provide reference for future cable maintenance and overhaul work.
In conclusion, a power cable fault tester is a very useful tool that can help us quickly and accurately locate and judge the location and nature of cable faults. When conducting on-site cable fault testing, it is necessary to make adequate preparations and test in accordance with the prescribed steps and methods to ensure the accuracy and reliability of the test results. At the same time, the maintenance and overhaul of cables should be strengthened, and potential faults should be found and dealt with in a timely manner to ensure the safe and stable operation of the power system.