Which type of fuse is designed to blow quickly under short-circuit conditions?

A fast-acting fuse is specifically designed to blow quickly under short-circuit conditions. The primary function of this type of fuse is to protect electrical circuits from excessive current that can occur during short circuits, which can lead to damage or hazards such as fire. Fast-acting fuses have low thermal mass and respond almost instantly to overcurrent situations, effectively disconnecting the circuit before significant damage can occur.

In contrast, slow-blow fuses are designed to tolerate short-term overloads while still providing protection during sustained excessive currents. This makes them ideal for applications where inrush currents are expected, such as in motors or transformers. Resettable fuses, also known as polyfuses, can revert to their operational state after an overload condition is removed, but they do not blow in the traditional sense. Safety fuses often refer to various types of fuses that provide additional protection but may not specifically denote the quick response characteristic associated with fast-acting fuses. Overall, the fast-acting fuse's ability to respond rapidly distinguishes it as the correct choice for protecting against short-circuit conditions.