By EPCOS 111
TDK extends its EPCOS ThermoFuse family of fuse-protected varistors with the compact NT series. ThermoFuse varistors are uniquely designed disk varistors connected in series with a thermally coupled fuse and, therefore, they are intrinsically safe. If the varistor overheats, the fuse trips and isolates the varistor from the grid. This safety measure prevents any potential damage on the PCB or to the components located near the varistor and greatly increases the reliability of the equipment to be protected. Both series are available in 2-leaded and 3-leaded types, with the third lead used to monitor whether the fuse has been activated.
The NT14 series (disk diameter 14 mm) is designed to absorb maximum surge currents with an 8/20 µs pulse of 6 kA at rated voltages of between 130 VRMS and 680 VRMS, while the NT20 series (disk diameter 20 mm) has a surge current capability with an 8/20 µs pulse of 10 kA at rated voltages of between 130 VRMS and 750 VRMS.
