A fusible link is a mechanical or electrical safety device. They are used in
fire sprinkler
A fire sprinkler or sprinkler head is the component of a fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been exceeded. Fire sprinklers are extensively used ...
heads to activate the sprinkler in the presence of heat. They are used in automobile electrical systems as a
fuse.
Mechanical fusible link
A mechanical fusible link is a device consisting of two strips of metal soldered together with a
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.
Sometimes the term "fusible alloy" is used to describe 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
A fire sprinkler or sprinkler head is the component of a fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been exceeded. Fire sprinklers are extensively used ...
systems and mechanical automatic door release mechanisms that close fire doors in warehouses, etc. Fire dampers in ventilation systems have fusible links so that the dampers close automatically in case of fire, limiting the spread of flame or hot gases through a building. Some high-security safes also utilize fusible link-based
relockers as a defense against torches and heat-producing tools. Mechanical fusible links come in a variety of designs and different temperature ratings.
Electrical fusible link
An electrical fusible link is a type of
electrical fuse
In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows t ...
that is constructed simply with a short piece of wire typically four
American wire gauge (AWG) 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.
[Jim Horner, ''Automotive electrical handbook'', Penguin, 1986, , pages 36-37 ]
See also
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Thermal fuse
*
Fuse (automotive)
Automotive fuses are a class of Fuse (electrical), fuses used to protect the wiring and electrical equipment for vehicles. They are generally rated for circuits no higher than 32 volts direct current, but some types are rated for 42-volt electri ...
References
{{Fire protection, state=collapsed
Safety equipment
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