In a dual element time delay fuse, what happens inside the fuse if an overload occurs?

In a dual element time delay fuse, when an overload occurs, the design of the fuse is such that one of the elements within the fuse is specifically designed to respond to the overload condition. The dual elements serve distinct purposes: one is for short-circuit protection and reacts quickly, while the other is for overload protection and is crafted to allow brief overloads to pass without immediately blowing.

When an overload condition occurs, the fusible element designed to handle overloads will heat up due to the increased current flow. If the overload persists long enough, this element will reach its melting point, causing a fusible pin to melt out. This action removes the conductive path within the fuse, thereby interrupting the circuit and preventing potential damage to the electrical system and connected equipment.

This mechanism is crucial for ensuring that transient, non-harmful overloads don't cause unnecessary interruptions while still providing necessary protection when sustained overloads occur. In essence, the melting of the fusible pin is a critical safety feature that protects against damage without compromising operational efficiency under normal conditions.