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 Locator Suppliers
Cable fault test cable fault test procedure When using the cable fault tester (echo method) to test the cable fault, the following procedures should be carried out: (1) Multimeter, shake meter or judge the nature of the cable fault from the cable pre-test results. (2) Select the appropriate test method according to the nature of the cable fault: the pulse method is best used for low-resistance faults and open-circuit faults, and of course, the flashover method can also be used for low-resistance faults. Leakage high resistance faults are best to use the flashover method (rush L method), some leaky high resistance faults can also use the direct flash method, but usually do not do this, it is best to use the direct flash method for flashover high resistance faults. You can also use both methods to measure and compare with each other to improve the accuracy of judgment.
(3) Select the working ground point, and lead out two ground wires from the selected ground point, one is connected to the ground of the instrument, and the other is connected to the ground of the high-voltage equipment. The selection principle of the working ground wire is to ensure that the test phase and it form a closed loop, so that the instrument can obtain the correct test waveform. It should also be noted that the working ground wire must be connected with the system ground, so that the ground of people, instruments, high-voltage equipment and the cable under test are in the same four-body position.
To ensure personal safety and equipment integrity. If the cable is faulty between phases, the working ground wire must be one of the phase wires, and the phase wire used as the ground wire must be connected to the system ground. For cables with lead-free bushings, the vast majority of faults are discharges to earth or space during high-voltage flashover tests.
In theory, the fault also forms a closed loop relative to the ground or space, but in fact the equivalent impedance in the loop is quite large, so the correct test waveform cannot be obtained on the instrument. If this situation is encountered in the test, the method of directly fixing the suspected fault point can be adopted to solve it. No matter what ground wire, its grounding point must be reliable.
⑷ Use the pulse method to test the entire length of the cable to calibrate the transmission speed of the cable under test. ⑸ According to the selected test method, make a rough test on the fault point. ⑹ After the rough measurement is completed, fix the fault point.
Cable Fault Test Procedure Cable Fault Test Shenzhen Noyafa Electronic Technology Co., Ltd.
Copyright © 2022 SHENZHEN NOYAFA ELECTRONIC CO.,LIMITED - www.noyafa.net All Rights Reserved.