Author: Noyafa–Cable Tester Manufacturer
Cable fault testing steps The detection of cable faults generally goes through four steps: diagnosis, distance measurement, path finding and location. 1. Diagnosis The diagnosis of the nature of the cable fault, that is, to determine the type and severity of the fault, so that the tester can prescribe the right medicine, and select the cable fault test step. The detection of cable faults generally goes through four steps of diagnosis, distance measurement, path detection and fixed point. 1. Diagnosis Diagnosis of the nature of the cable fault, that is, to determine the type and severity of the fault, so that the tester can prescribe the right medicine and choose the appropriate cable fault location and fixed-point method.
Use a megohmmeter and a multimeter to measure the fault resistance to determine whether the cable fault is high resistance or low resistance; whether it is a flashover or a closed fault; whether it is grounding, short circuit, disconnection, or a combination of them; whether it is single-phase, two-phase, or three-phase. Phase failure. 2. Distance measurement Cable fault location, also known as rough measurement, uses an instrument at one end of the cable to determine the fault distance. The commonly used fault location methods in the field include the classical bridge method and the modern traveling wave method. 3. The GDBN-012 cable path identification instrument produced by our company is used for the path finding. 4. The legal point of the acousto-magnetic synchronization of the fault fixed point: the electromagnetic signal of the discharge is used for synchronization, the sound signal is digitally sampled, and the sound waveform at the moment of the discharge is displayed on the liquid crystal. On the screen, the waveform can be maintained continuously for the operator to distinguish carefully, avoiding the shortcoming of the transient sound, and the actual discharge waveform is obviously different from the surrounding noise. More importantly, the sound waveforms of multiple discharges are very similar. When it is observed that the sound waveform of multiple discharges is the same, it can be clearly judged that the discharge sound has been collected.
Since the response range of the acoustic measurement method is generally small, when the discharge sound is heard, it is very close to the fault point, generally not more than 5m, or even within 1-2m.
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