Views:218 Author:Site Editor Publish Time: 2020-11-12 Origin:Site
In recent years of social development, the scale of low-voltage distribution network lines is also expanding. As an important part of the overhead power distribution, low-voltage distribution network lines directly affect people's lives and property safety. Therefore, it is necessary to do a good job in the operation, maintenance and management of low-voltage lines. Let us analyze the common faults of low-voltage overhead power lines.
The most common occurrence of low-voltage distribution lines is open circuit faults. Due to the intricacies of overhead electric lines, the possibility of arcing in the circuit increases, which may cause an electric fire in serious cases. There are several situations that may cause an open circuit:
1). The wires are easy to come into contact with sharp objects, or the operating environment of the distribution line is not good, it is easy to be interfered with by external forces, and the stability is poor.
2). The overhead distribution lines may react with some natural substances and be affected. For example, wires in the air are in contact with acid rain, and converting overhead power lines underground are in contact with water or other substances in the soil for a long time, thereby being corroded, causing the insulating layer of the wires to be exposed and breaking down.
Overload fault means that the actual load on the line exceeds the maximum allowable value of the line, causing the line to be paralyzed. When the current is transmitted through the line, a part of the heat will be generated. Normally, it will dissipate by itself during normal use. The overload situation is that excess heat is generated by the overload current， the circuit temperature is too high, which causes the insulator to age in advance. Low-voltage lines are mainly directly related to households with electricity. The continuous operation of aging insulators is prone to spontaneous combustion, which greatly affects power distribution lines and even personal safety.
Power short circuit faults are also common faults in the operation of power grid systems. The common causes of cable short circuit are as follows: damaged wire insulation, small cable cross-sectional area, connection problems, and electrical operation violations.
A ground fault is also called short circuit to earth, which means that the wire is damaged, and the ground wire fails to insulate the wire from the ground, resulting in a ground short circuit fault of the distribution line. Ground current leakage is usually divided into normal current leakage and ground-fault current leakage. Because the grounding wire and the faulty wire will discharge, it will cause the overall temperature of the circuit to rise, which will affect the reliability of electrical equipment. A ground fault indicator will help you find out the problem if a ground fault happens.
The most common cause of line leakage is weathering or aging of line insulators. The aging line is exposed to the outside world, which increases the probability of line leakage faults.