Introduction to Low Voltage Cable Application
Low-voltage cables refer to power cables whose operating voltage is less than 1kv. Low-voltage cables are composed of wire cores, insulating layers and protective layers. They are used for connecting cables from power distribution cabinets to equipment ends. Compared with high-voltage cables, low-voltage cables are more technologically structured and used. The range is also different, the same is that they are all carriers for conducting electrical energy, and their use range is ubiquitous.
The main causes of cable failure
When the cable fails, we first try to solve the failure and resume operation. In addition, we must analyze the cable failure and analyze the specific reasons. According to the data of the after-sales service department of Dingsheng Electric Power, we can eliminate the problem of the quality of the cable itself. There are two main reasons for the failure of low-voltage cables. First, the external insulation is damaged due to external force factors, and the ground fault caused by moisture. Second, the joints are not handled properly, resulting in short-circuit faults caused by moisture.
Low-voltage cable fault finding method
After the cable fails, firstly use a multimeter or an electronic megohmmeter to analyze the current fault situation through data. See which phase has a cable fault. After the faulty phase is determined, use a multimeter to measure the resistance to ground. If the measured resistance is greater than 200 ohms, you can use the low-voltage cable fault finding method.
Low-voltage cable fault finding method (step voltage method)
The step voltage method is suitable for cable faults of all voltage levels of ground faults. It is a method of finding cable faults by using the voltage between its two feet around the ground current entry point. The specific wiring method is the red color of the power cable fault detector. The clip is connected to the faulty phase of the cable under test, the black clip is grounded, and then the induction magnet bar and step voltage sampler of the path are connected, and the power is turned on. After a short synchronization signal, the host sends an electromagnetic pulse and searches along the road through the magnet bar receiver. , the path of the cable can be accurately inspected, and then, along the found path, the fault location of the cable is carried out. The specific method is that the left and right ends of the step voltage sampler are marked with red and green, and the indicators are also corresponding. The indicator mark of the step voltage sampler is inserted into the soil. The red and green directions of the indicator represent the direction of the fault point of the cable. If you encounter a hard road, the watering can also be accurately measured. The right side indicates, and so on, the fault point can be determined.