Thermal fuse will activate and disconnect varistor from its power circuit

Consisting of a disk varistor in series with a thermally-coupled fuse, Epcos T Series ThermoFuse varistors are now stocked by Digi-Key. If the varistor overheats, the thermal fuse activates and disconnects it from the power circuit, which increases reliability and protects the equipment. Both the housing and the coating of the varistor are made of flame-retardant material. The ThermoFuse varistor has three terminal wires; two are connected to the active lines while the third terminal can be used for status signalling. The T series lineup currently comprises types that feature disk varistors with diameters of 14mm and 20mm and are designed for maximum operating voltages of between 130V and 1000V RMS. The ThermoFuse varistors can withstand surge currents of up to 10.000A (8/20µs) and absorb up to 410 J (2ms). Applications include household appliances, power supply units, inverters in solar power systems, drives, lighting, communication and data systems, and transient voltage surge suppression (TVSS).