In the orderly and stable operation process of the photovoltaic system, the bolt-type photovoltaic fuse is like a loyal guard, taking on the extremely critical task of overcurrent protection. Whether it can work normally is directly related to whether the photovoltaic power station can continue to operate safely and efficiently. Therefore, regular comprehensive inspection of bolt-type photovoltaic fuses has become the core point of daily operation and maintenance of photovoltaic power stations.
Appearance inspection
Appearance inspection is the most direct and basic of all detection methods, but it should not be underestimated. At the beginning of the inspection, the operation and maintenance personnel need to hold a strong flashlight and observe the outer shell of the fuse at an angle of about 45 degrees. The first concern is whether the outer shell has abnormal signs such as damage, deformation or discoloration. Under normal working conditions, the fuse shell should be like a brand new armor, maintaining an intact state, with a smooth surface and no cracks. Once the outer shell is even slightly damaged, the components that were originally tightly protected inside will be exposed. In the complex electrical environment of the photovoltaic system, this can easily cause dangerous conditions such as short circuits, instantly disrupting the stable operation of the system and causing the entire photovoltaic power station to be paralyzed.
When the fuse shell is found to change color, especially when it is obviously black, this is undoubtedly a strong warning signal. This means that the fuse may have experienced severe overheating during its past operation. The root cause of overheating is most likely overcurrent, that is, at a certain moment, the current flowing through the fuse exceeds its rated tolerance range. Even if the fuse has not blown at this moment, this abnormal overheating has caused potential damage to its internal structure and performance, and it may "strike" at any time. Therefore, once such a phenomenon is observed, the operation and maintenance personnel must immediately be alert and further investigate the cause of the abnormal system current. Through professional electrical testing equipment, each line node and electrical equipment of the photovoltaic system are tested one by one to find out the "culprit" causing the overcurrent.
Checking the connection parts at both ends of the fuse is also a key step in the appearance inspection. It is necessary to focus on whether the connection bolts are firm and whether there are signs of looseness. The firmness of the connection bolts directly affects the connection quality between the fuse and the circuit system. If the connecting bolts become loose, gaps will appear in the originally tight electrical connection, which will significantly increase the contact resistance. According to Joule's law, when the resistance increases, when the current passes through, a large amount of additional heat will be generated at the contact point. This is like placing a "small stove" next to the fuse, which continuously bakes the fuse, accelerates its aging process, and may even cause it to blow in a short period of time, thereby interrupting the normal power supply of the photovoltaic system. Therefore, once the bolts are found to be loose, the operation and maintenance personnel must use an appropriate torque wrench in time to tighten the bolts accurately according to the torque value specified in the product manual, so as to prevent the further expansion of safety hazards and ensure that the fuse and the circuit system always maintain a good electrical connection.
