Power cables are important equipment in the power system, so the stable operation of power cables is closely related to people's normal life and work. Minor issues may affect people's normal work and life, while severe ones can cause fires, threatening people's lives and property safety. Therefore, it is very necessary to handle power cable faults in a timely manner. Below, Asia Cable will introduce the fault finding and fault analysis of power cables.
Mechanical damage is mainly caused by physical collisions, pulling, and other reasons. According to relevant statistical data, mechanical damage is the most common cause of cable faults, specifically including the following types:
③ Under natural conditions, the middle joints or terminal joints of cables are subjected to natural tension and expansion of internal insulating glue, leading to rupture of the cable protective sheath and causing fault problems. Moisture ingress in power cable insulation mainly refers to the poor sealing of middle joints or terminal joints of power cables, allowing external moisture to enter and cause insulation dampness. In addition, if the cable quality is poor, defects such as small holes or cracks on the protective sheath can also cause cable dampness.
In actual situations, the occurrence of air gap discharge inside the insulation of power cables can cause local overheating of the insulation, leading to carbonization of the cable insulation. Cables installed in densely populated areas or poorly ventilated areas, or parts close to heat pipelines, can all cause cable overheating. Additionally, prolonged operation of power cables under overload conditions can also lead to cable overheating.
Short circuit faults are a common type of fault in the operation of power cables. Short circuit faults include high resistance short circuit faults and low resistance short circuit faults. When a short circuit fault occurs in a cable, it causes the fuse in the cable protection device to melt, resulting in tripping. Due to the melting of the fuse, the cable insulation is burned by high temperature, and the fault point of the power cable is the short circuit fault. Ground faults in power cables are also divided into low resistance ground faults and high resistance ground faults.How to find the location of cable leakage Ground faults are different from short circuit faults. The two types of ground faults differ significantly and can be clearly distinguished through tools and the nature of the fault.
Under normal circumstances, low resistance ground faults need to be detected using a low voltage bridge, and the ground resistance is less than 20-100Ω, while high resistance ground faults need to be detected using a high voltage bridge, and the resistance value needs to be greater than 100Ω. In actual situations, if a ground fault occurs, fire leakage detector the device specifically used for ground detection in the power system will issue a fault signal, and the leakage protection device will also control the system to trip. Although cables bring great convenience to our lives, there are also many uncontrollable factors. The quality of power cables directly affects the safe operation of the line. Once the line cannot operate safely and stably, the losses caused by faults in life and economy are unpredictable. Therefore, our Asia Cable should fundamentally prevent the occurrence of cable faults, minimize cable accidents, start from the details, and strive to achieve the goal of safe and stable power supply.
