What is the difference between an expulsion type fuse cutout and a vacuum fuse?

Expulsion type fuse cutout is a common overcurrent protection device. Its working principle is based on the internal filling of quartz sand or other materials to generate high-pressure gas during the fusing process, which quickly cools and extinguishes the arc through the jet effect, thereby cutting off the circuit. This design is suitable for medium and low voltage environments, with a relatively simple structure and low cost. In contrast, vacuum fuses use a high vacuum environment as an arc extinguishing medium, extinguishing the arc through rapid ion diffusion in the vacuum when disconnecting the current, avoiding the need for external fillers. Both are important safety components in electrical systems, but there are significant differences in their basic mechanisms, which affects their application range and performance.

In terms of specific operation, expulsion type fuse cutout relies on the physical reaction of the internal filler to generate a jet flow. Although it effectively suppresses the arc, its operation may produce gas emissions and residues, requiring regular maintenance; vacuum fuses do not have such problems, the arc extinguishing process is cleaner and faster, suitable for high-voltage scenarios but with higher costs. The structure of the ejection type fuse is relatively complex, and its durability is slightly worse under frequent overload conditions, while the vacuum type achieves long life and low maintenance with its vacuum sealing design. Therefore, the ejection type fuse is more suitable for economical applications, but the vacuum fuse has obvious advantages in high reliability and silent environments.

In general, the expulsion type fuse cutout has advantages in price and ease of use, and is widely used in power distribution systems and industrial equipment, but its efficiency is slightly lower and the maintenance requirements are greater; the vacuum fuse stands out with its high performance and environmental protection characteristics, especially suitable for high-voltage power transmission and transformation. The choice of which fuse should be combined with actual needs, and the ejection type fuse is still competitive in cost-sensitive projects.