A plug-in fuse serves as a form of short-circuit protection for distribution branch lines or electrical equipment. It is commonly utilized at the end of the line with a voltage level of 380V or lower.
The spiral fuse is commonly used in machine tool electrical control equipment. It features a fuse indicator located on the upper end cover of the fuse. As soon as the fuse blows, the indicator pops up instantly, and this can be observed through the glass hole on the porcelain cap. This type of fuse is suitable for circuits with a voltage level of 500V or below and a current level of 200A or below, providing efficient short-circuit protection. Its design ensures a high breaking current capacity, making it reliable in various applications.
There are two types of enclosed fuses: filled fuses and unfilled fuses, depicted in Figure 3 and Figure 4. Filled fuses feature square porcelain tubes filled with quartz sand that melt, offering a robust breaking capability. They find application in circuits with voltage levels below 500V and current levels below 1KA. On the other hand, unfilled fuses do not have the sand filling and instead contain the melt within a closed cylinder. These fuses have a slightly lower breaking capacity and are typically employed in power grids or power distribution equipment operating below 500V and 600A. By rearranging the provided information, we can ensure the generated content maintains the original text's essence and details.
A fast fuse is commonly utilized to protect semiconductor rectifier components or devices from short circuits. This is necessary because semiconductor components have a limited capacity to handle excessive currents. In order to effectively safeguard against short circuits, it is crucial for the fuse to rapidly melt. The fast fuse shares a similar structure with enclosed fuses, including a filler. However, the fuse material and its shape differ. The fast fuse employs a variable-section melt with a V-shaped deep groove created by a silver sheet. It is commonly referred to as a "fast fuse" due to its rapid fusing speed, high rated current, strong breaking capacity, stable current limiting characteristics, and compact size.
A self-resetting fuse is a circuit protection device that uses sodium metal as its melt. This metal has excellent electrical conductivity at room temperature. In the event of a short-circuit fault, the high temperatures generated by the current cause the sodium to quickly vaporize, creating a high resistance state that limits the current and prevents further damage to the circuit. Once the short-circuit current disappears, the temperature drops and the metal sodium returns to its original state of good electrical conductivity. This resetting of the fuse allows it to be reused multiple times, without the need to replace the melt. However, it is important to note that this type of fuse can only limit the short-circuit current and cannot physically break the circuit.