Fusible link
Encyclopedia
Fusible links include mechanical and electrical devices.
A mechanical fusible link is a device consisting of two strips of metal soldered together with a fusible alloy
that is designed to melt at a specific temperature, thus allowing the two pieces to separate. Mechanical fusible links are utilized as the triggering device in fire sprinkler
systems and mechanical automatic door release mechanisms that close fire doors in warehouses, etc. Some high-security safes also utilize fusible link-based relocker
s as a defense against torches and heat-producing tools. Mechanical fusible links come in a variety of designs and different temperature ratings.
An electrical fusible link is a type of electrical fuse
that is constructed simply with a short piece of wire typically four American wire gauge
sizes smaller than the wire that is being protected. For example, an AWG 16 fusible link might be used to protect AWG 12 wiring. Electrical fusible links are common in high-current automotive applications. The wire in an electrical fusible link is encased in high-temperature fire-resistant insulation to reduce hazards when the wire melts.
A mechanical fusible link is a device consisting of two strips of metal soldered together with a fusible alloy
Fusible alloy
A fusible alloy is a metal alloy capable of being easily fused, i.e. easily meltable, at relatively low temperatures. Fusible alloys are commonly, but not necessarily, eutectic alloys....
that is designed to melt at a specific temperature, thus allowing the two pieces to separate. Mechanical fusible links are utilized as the triggering device in fire sprinkler
Fire sprinkler
A fire sprinkler system is an active fire protection measure, consisting of a water supply system, providing adequate pressure and flowrate to a water distribution piping system, onto which fire sprinklers are connected...
systems and mechanical automatic door release mechanisms that close fire doors in warehouses, etc. Some high-security safes also utilize fusible link-based relocker
Relocker
A relocker is one of various mechanisms intended to keep a safe or vault locked in a burglary attempt.There are two basic classes of relockers:* Relock trigger , an internal relocker built into the primary lock...
s as a defense against torches and heat-producing tools. Mechanical fusible links come in a variety of designs and different temperature ratings.
An electrical fusible link is a type of electrical fuse
Fuse (electrical)
In electronics and electrical engineering, a fuse is a type of low resistance resistor that acts as a sacrificial device to provide overcurrent protection, of either the load or source circuit...
that is constructed simply with a short piece of wire typically four American wire gauge
American wire gauge
American wire gauge , also known as the Brown & Sharpe wire gauge, is a standardized wire gauge system used since 1857 predominantly in the United States and Canada for the diameters of round, solid, nonferrous, electrically conducting wire...
sizes smaller than the wire that is being protected. For example, an AWG 16 fusible link might be used to protect AWG 12 wiring. Electrical fusible links are common in high-current automotive applications. The wire in an electrical fusible link is encased in high-temperature fire-resistant insulation to reduce hazards when the wire melts.