The fuse is an electrical protection device, which is composed of a metal fuse (melt, fuse) and a contact structure supporting the fuse, which is mainly divided into the following six types:
1.Porcelain plug-in fuse, simple structure, more specifications, long service life, porcelain material, good flame retardant performance, safe and reliable.
2.Spiral fuse, when the fuse is blown, the color chip is bounced off, and the fuse tube needs to be replaced, which is often used in the distribution cabinet.
3.Enclosed fuse, using a high-temperature sealed protective tube, with a fuse or fuse inside. When the fuse melts, the air pressure in the pipe is very high, which can play the role of arc extinguishing and avoid interphase short circuit. This type of fuse is often used for short-circuit protection on loads with large capacities.
4.The main characteristics of the filler fuse are the current limiting effect and the high limit breaking capacity. Therefore, this kind of fuse is used in power systems with large short-circuit currents and complete sets of power distribution devices.
5.Self-reversing fuses, the modern low-voltage electrical capacity is gradually increasing, the short-circuit current of low-voltage distribution lines is also increasing, and the breaking capacity of the switching components required for system protection is also increasing, for which some new current-limiting components have emerged, such as self-resetting fuses. A self-resetting fuse is a fuse that can be used for multiple actions, and the melt can automatically return to its original state immediately after breaking the overload or short-circuit current. The self-resettable fuse is characterized by a large breaking current.
6.Resettable fuses, which are made up of specially treated polymeric resin and conductive particles distributed inside. When the line is short-circuited or overloaded, the high current flowing through the resettable fuse melts the polymeric resin, and the volume grows rapidly, forming a high-resistance state, and the working current decreases rapidly, thereby limiting and protecting the circuit. When the fault is solved, the resettable fuse is re-cooled and crystallized, the volume shrinks, the conductive particles re-form a conductive path, and the resettable fuse returns to a low-impedance state, so as to complete the protection of the circuit without manual replacement.