The TDK EPCOS T series of ThermoFuse™ varistors consist of a disk varistor in series with a thermally coupled fuse. If the varistor overheats, the thermal fuse activates and disconnects it from the power circuit, thus preventing the occurrence of fires, in the worst case. This 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 14 mm and 20 mm and are designed for maximum operating voltages of between 130 and 1000 VRMS. The new ThermoFuse varistors can withstand surge currents of up to 10.000 A (8/20 µs) and absorb up to 410 J (2 ms).
Major applications for ThermoFuse varistors are:
· Household appliances
· Power supply units
· Inverters in solar power systems
· Lighting applications
· Communication and data systems
· Transient voltage surge suppression (TVSS)