1. Between the determination of cable fault, the tester must first determine the nature of the cable fault in addition to mastering the performance and operation methods of the machine, so as to adopt appropriate working methods and test methods. First, use a megohm meter or multimeter to measure the insulation resistance between each relative ground and phase at one end of the cable. According to the resistance value, it is a low resistance short circuit or open line break, or a high resistance flashover fault.
2. When the resistance value is less than 100 ohms, it is a low resistance fault, 0 ~ tens of ohms is a short circuit fault, and the resistance value is extremely high to unlimited. Whether the line is broken, you can also connect the cable terminal to the universal meter at the beginning to measure the resistance value of the two phases short-circuited to confirm. Such faults can be measured directly by low pulse method.
3. When the resistance value is very high (hundreds of megabits and gigabits) and there is a transient discharge phenomenon in the high-voltage test, such faults are generally called flashover faults, which can be determined by DC high-voltage flash measurement method.
4. The resistance value of high resistance fault is higher than that of low resistance fault, which can be determined by DC high voltage flash measurement method when doing high voltage experiment.
5. After a rough test in a certain way, determine the point. If necessary, find the cable path and measure the cable length or distance.
Post time: Apr-02-2024