Fast and accurate location of cable fault point

When the total length of the fault cable is known as the data, the method to accurately locate the fault point of the cable has the following steps: suspend the fault cable and take one end of the fault cable as the detection point; The digital insulation resistance tester is used to measure the insulation resistance between the isolated wire core and between the wire core and the screen steel strip, so as to determine the fault wire core, that is, the fault wire core. Then the dc resistance between the fault line cores and between the fault line cores and the screen steel strip is measured. Is the measured dc resistance less than or equal to 1? K Ω, the use of cable fault location bridge and any wave reflection to locate trouble points in cable fault line measurement to determine the fault point and the length of cable between the test point value, to determine the fault point location; If the position difference of the fault point measured by the two devices is larger than the tolerance difference, the test result of the fault locator of the wave reflection cable shall prevail. If the difference is less than or equal to the tolerance distance, the distance between the failure points of the tested equipment shall be determined as the range of the failure points. Measure the dc resistance is not less than 1 k Ω, any trouble wave reflection to locate trouble points in cable is used to measure the wire core to determine the fault point and the length of cable between the test point value, to determine the fault point location, and fault point location as the center, radius of gap, should determine the scope of the point of failure; If the measured dc resistance is different, the wave reflection cable fault locator is used to measure any fault unit and determine the cable length between the fault point and the detection point, thus determining the location of the fault point. The above tolerance difference of 5mC) apply pulse voltage to the fault iron core or between the fault iron core and the steel strip, and set the cable fault locating power supply at the detection point; Within the scope of the fault point determined in step b), the cable fault locator shall be used according to reasonable judgment to find the exact location of the fault point. In the range of fault points determined in step b), the acoustic magnetic synchronization method is adopted to accurately locate the cable fault points.