What are the reasons why the insulation layer of photovoltaic cables in solar power stations is often broken down?

Solar photovoltaic cable is often broken down generally refers to the insulation layer and sheath layer of photovoltaic cable due to external force damage, as well as the deterioration of the quality of the insulation layer and other factors, directly destroy the original insulation performance, loss of the original insulation performance, core wire to the operation of photovoltaic cable and so on. The discharge between the core wire and the outer sheath of the photovoltaic cable causes a short circuit to the ground. There are five reasons for the insulation breakdown of photovoltaic cables：

mechanical damage

Due to the heavy weight, the excavator accidentally pulled the cable. When the cable is bent, the photovoltaic cable bends too much and damages the insulation layer. The photovoltaic cable is severely squeezed during transportation, and the insulation and protective layers are damaged. The bottom layer of the buried photovoltaic cable is too strong. Both can damage the insulation layer and even damage the cable. To avoid mechanical damage to the photovoltaic cable, a new photovoltaic cable can be replaced. If the photovoltaic cable is laid along the wall, the ground should be clearly marked and soil should be collected near the photovoltaic cable in time.

Improper construction

Due to the poor construction method and the poor quality of materials used, the weak link in the middle of the photovoltaic cable connection is broken, resulting in insulation breakdown. In order to prevent this phenomenon, the installation quality of photovoltaic cables should be improved. During the manufacturing and installation of photovoltaic cables, the insulation bags should be tight and no gaps should be allowed. The epoxy resin and quartz powder should be strictly dried before application to prevent bubbles and moisture from connecting the photovoltaic cable, and to strengthen the insulation treatment of the edge of the lead sheath.

Insulation and sheathing are damp

Due to the poor construction of the photovoltaic cable, the moisture enters the interior along the conductor, or the protective layer of the photovoltaic cable breaks, allowing the moisture to enter. The lead-clad photovoltaic cable, which is laid near the source of the earthquake, has fatigue and cracking due to long-term vibration. The photovoltaic cable sheath is corroded to create voids. There are small holes or cracks in the lead package due to poor manufacturing quality. In these cases, the maintenance of the outer layer of the photovoltaic cable should be strengthened and a layer of asphalt should be applied to the outer sheath regularly.

overvoltage

The insulation layer is broken down due to excessive voltage or internal overvoltage, especially when multiple photovoltaic cables are broken at the same time due to internal overvoltage of the system. Therefore, people should be sent to install lightning arresters to improve the technical level of automatic protection of solar energy systems.

insulation aging

In the long-term operation of photovoltaic cables, due to poor heat dissipation or overload, the electrical and mechanical properties of insulating materials become worse, and the insulation layer becomes brittle or broken. If this is the case, preventive voltage testing of the photovoltaic cable should be carried out regularly. If it is found that the reduction of photovoltaic cable insulation cannot meet the requirements of safe operation, new photovoltaic cables should be replaced.

If you have more questions or need more information, please contact us and our professional team will be happy to support and answer you.