The fuse, also known as a safety fuse or a sacrificial fuse, is a crucial electrical component. Its core function is to interrupt the circuit by melting its own fuse element when the current exceeds a specified value. This mechanism makes the fuse a key device for circuit protection, effectively preventing equipment damage or dangerous situations such as fires caused by overcurrent or short circuits.
Fuses are widely used in various power systems and electrical equipment, including high and low-voltage distribution systems, industrial production lines, household circuits, and automotive circuits. Their crucial role in these systems is to prevent circuit overloads, short circuits, and other faults, protecting electrical equipment from damage.
The cutout body, an open frame that supports the fuse holder and a ribbed porcelain or polymer insulator that electrically isolates the conductive portions of the assembly from the support to which the insulator is fastened.
The fuse holder, also called the "fuse tube" or "door", an insulating tube which contains the replaceable fuse element. When the contained fuse melts ("blows"), it opens the circuit, and the fuse holder drops out of the upper contact and hangs from a hinge on its lower end. This hanging fuse holder provides a visible indication that the fuse has operated and assurance that the circuit is open. The circuit can also be opened manually by pulling out the fuse holder using a hot stick. The fuse holder is typically made out of a fiberglass tube with a covering and metal contact points. As a fuse holder ages, the coating on the fiberglass will degrade and the fiberglass tube will start "shedding". The tube starts out with a pinkish hue then becomes white and then starts to "shed" fiberglass.
The fuse element, or "fuse link", is the replaceable portion of the assembly that melts and breaks the circuit when the electric current through it exceeds its rated current value. There are many types of fuse elements for many different uses such as a type T fuse also known as a "slow-blow fuse" being used for sidelines.
