Safety Thermal Fuse By Orbit Electronics

Safety Thermal Fuse uses an organic thermosensitive pellet inside a metal case.
Thermal fuses (or thermal cut-offs) are "one-shot", non-resettable, temperature-sensitive devices that provides ultimate temperature protection in safety critical circuit. Thermal Cutoffs respond to temperature by interrupting an electrical circuit when the operating and/or environmental temperature exceeds the thermal rating of the thermal fuse.

This is accomplished when the organic pellet experiences a phase change, allowing the spring activated contacts to permanently open the circuits. Mainly defined by their temperature setting but also by the current rating, which is the maximum continuous current that can be applied. Thermal Cutoffs respond to temperature by interrupting an electrical circuit when the operating and/or environmental temperature exceeds the thermal rating of the thermal fuse.