Recently, I heard from a colleague that the fuse of his company's electric box burned twice in two months. The first time it was a short circuit, and the second time it was inexplicable. Because it is frequent, the circuit was checked, but no abnormality was found. Later, after his careful observation, the problem actually lies in the installation, which also aroused my curiosity. It stands to reason that there should be no installation problem for the fuse of the distribution cabinet. Everyone knows that the fuse of the distribution cabinet is embedded by pushing and pulling the handle, and safety is the first.
I didn't understand the device he said until I saw the picture. It turned out that when replacing the fuse, the thrust was too strong and too large, which caused the handle connecting rod to bend and deform, and the fuse could not be pushed into place. The fuse is in a semi-embedded working state. Although it was close contact, the contact area became smaller, which left a hidden danger for fever. After a long time, the fuse blew for no reason. As can be seen from the picture, the fuse is not pushed in place, and the surface of the fuse changes color due to thermal oxidation. Pay attention to it when checking, and you will find it. This kind of chronic fault can be avoided rationally, but it is often ignored because of carelessness. Although this has certain particularity, it also deserves everyone's attention. As an electrician, details should not be underestimated.