The role and materials of the fuse shell

Fuse element is generally thinner, softer, the role of the shell is to fix the fuse element, so that the three parts form a rigid whole, easy to install and use. It must have good mechanical strength, insulation, heat resistance and flame retardancy, and should not break, deform, burn or short-circuit during use. Only in this way can it resist the impact of arc temperature and mechanical force and maintain the integrity of the fuse as a whole.

The tube body is usually made of ceramic or melamine tube, and different types of fuses are made of different materials.
For example, the British standard fuse is mainly used in equipment produced in Commonwealth countries, the shell is made of ceramic, the product has a small size, cost-effective features, especially favored by UPS manufacturers below 240V.

North American Fuse is the most widely used one, covering most of the power electronic products. The North American standard fuse housing is made of melamine mesh and ceramic lamination process, which has strong impact resistance, small Joule integral value, small power loss and excellent DC performance, and is widely used in substations, electric vehicles and other occasions.

Euro Square Body Fuse is made of ceramic material.This product is characterized by low operating temperature, small power loss, small Joule integral value, etc. It is suitable for applications requiring compact structure, superior performance and high power, especially in the fields of electric vehicles, electric vehicle charging and energy storage.

The role and materials of arc extinguishing equipment for fuses

The fuses used in power supply circuits and high-power equipment also have arc extinguishing equipment. Since the circuit protected by this type of fuse not only has a high operating current, but also has a high voltage at both ends when the fuse is fused, it is often the case that the fuse has been fused (burned) or even vaporized, but the current has not been cut off.The reason is that in the instant of fusing, under the action of voltage and current, the fuse between the two electrodes to produce an arc. This arc extinguishing equipment must have strong insulation and good thermal conductivity, and negatively charged.

Quartz sand is a commonly used arc extinguishing material.

It can absorb the conductor and buffer arc temperature and mechanical shock, splitting and cooling arc, and produce a large amount of gas pressure, the arc to play the role of de-ionization, quickly extinguish the arc, thus cutting off the circuit or the faulty equipment and the grid to isolate, to ensure the safe operation of other areas on the grid or other equipment.

In addition, there are fuses with a fuse indication device, which is a parallel wire, when the main fuse element fuses, together with the fuse, the high temperature triggers the gunpowder or stored elasticity, resulting in a visible displacement or indication of switch action. Its role is when the fuse action (melting), its appearance of certain changes to facilitate the discovery of maintenance personnel, such as: luminous, color changing, pop-up solid indicator.