Working Mechanism Of Drop-out Fuse

In power distribution networks, the drop out fuse 22kv fuse is commonly used at voltage levels of 10kV and above, serving as a short-circuit protection switch for outdoor high-voltage lines and the primary side of distribution transformers.

When the system is under normal operation, the fuse remains intact, and the fuse tube forms a reliable electrical connection with the stationary contact through the tension of the fuse, providing a continuous current to the line or transformer.

If a short circuit or overload occurs, the fuse quickly melts due to the excessive current. During the melting process, an electric arc is generated, and the material covering the fuse tube heats up, producing a large amount of gas. The ejected gas forms a longitudinal airflow, elongating and extinguishing the arc. At this point, the fuse tube, having lost its tension, falls under its own weight and the action of a spring, thereby breaking the circuit and isolating the faulty section.