Author: Noyafa–CCTV Tester
How does a cable fault tester work? Cable fault tester The direct flash method is suitable for measuring high resistance flashover faults. In the actual test, the operation method and wiring diagram are basically the same as the flash method (no ball gap). Cable fault tester Direct flash question: How does a cable fault tester work? Answer: The direct flash method of the cable fault tester is suitable for measuring high resistance flashover faults.
In the actual test, the operation method and wiring diagram are basically the same as the flash method (no ball gap). The cable fault tester direct flash method is also divided into two methods: voltage sampling and current sampling. We recommend using the current sample.
When a DC high voltage is applied to a certain value during the fault phase, the fault point is decomposed and short-circuited. At this time, the reverse switching voltage V10 is generated from the fault point. Voltage is transmitted along the cable.
When the fault is transmitted to the beginning, the impedance at the beginning is greater than the characteristic impedance of the cable, so the reflection is 2V10, this voltage continues to transmit backwards and short-circuits after the fault point, so the reflected voltage is -2V1, after a period of negative reflected voltage, It is transmitted to the beginning, so it goes back and forth a few times until the flashover discharge ends and stops. The cable fault tester flash method is suitable for testing high resistance leakage faults. For other types of high resistance and low resistance faults, a cable fault tester flash test can also be used.
The test method is the same as the direct flash method, except that no DC high voltage is applied to the cable but a surge voltage is applied through the ball gap so that the fault clicks and discharges, and the reflected voltage (or current is generated, and the instrument records the state of the transient. Waveform Analysis Used to locate the fault point. It is the primary method for measuring high impedance and flashover faults.
The same sampling method is also divided into voltage sampling and current sampling. Of course, the subdivision can be divided into high-side and low-side voltage sampling, inductance and resistance sampling, startup and termination sampling. Since the low-side current sampling wiring is simple, reliable, and easy to identify, the current sampling method is recommended.
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