NOYAFA Electronic specializing in testing instruments and cable testers for 16 years
Language
NOYAFA Electronic specializing in testing instruments and cable testers for 16 years
Author: Noyafa–Cable Tester Manufacturer
Question: How does the cable fault tester work? Answer: The transmission cable is damaged by external force, humidity, insulation aging, etc., which will cause line transmission failure, which will seriously affect normal production and service life. It is necessary to quickly find the fault point for troubleshooting. Hence the question: how does a cable fault tester work? Answer: The transmission cable is damaged by external force, humidity, insulation aging, etc., which will cause line transmission failure, which will seriously affect normal production and service life. It is necessary to quickly find the fault point for troubleshooting. Hence the need for cable fault testers, a lot of people I don't know how the equipment works.
This article will show you how the device works. First, the working principle of the DC fault test method of the 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).
The 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.
Second, the working principle of the cable fault tester affects the high-voltage flash test method: the flash method is suitable for testing high-resistance leakage faults. Flash tests can also be used for other types of high- and low-resistance faults. 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 for fault clicks and discharges, as well as reflected voltage (or current), and the instrument records the state of the transient.
Waveform analysis is 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. Third, the working principle of the low-voltage pulse test method of the cable fault tester: The low-voltage pulse test method has the characteristics of simple operation, easy waveform identification and high precision.
For short circuit, low resistance and broken wire faults, this method can be used to directly determine the distance to fault. Even in the absence of such a fault, the full length or speed of the cable can be measured by the low voltage pulse method prior to the high voltage flashover test. Compared with the flashover test waveform, it is usually convenient for waveform analysis to quickly determine the fault point.
The working principle of the cable fault tester is actually very simple. You can only use this device better if you understand how it works.
Copyright © 2022 SHENZHEN NOYAFA ELECTRONIC CO.,LIMITED - www.noyafa.net All Rights Reserved.