ThermoFuse™ NT Series Varistors

TDK's EPCOS ThermoFuse varistors offer compact overvoltage protection with an integrated fuse

Image of EPCOS NT series ThermoFuse varistor 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.


Features and Benefits
  • Compact size
  • Wide range of voltages from 130 VRMS to 750 VRMS
  • High surge current capability of up to 10 kA
  • UL 1449 listed
  • Ballasts for lighting
  • Home appliances
  • Power supplies
  • Inverters for solar installations
  • Frequency converters for drives
  • Smart meters
  • General protection of electrical wiring and installations

ThermoFuse™ NT Series Varistors

ImageManufacturer Part NumberDescriptionMaximum AC VoltsMaximum DC VoltsVaristor Voltage (Min)Available QuantityView Details
VARISTOR 470V 6KA DISC 17MMB72214R2301K101VARISTOR 470V 6KA DISC 17MM300V385V423V820 - ImmediateView Details
VARISTOR 430V 6KA DISC 17MMB72214R2271K101VARISTOR 430V 6KA DISC 17MM275V350V387V827 - ImmediateView Details
VARISTOR 510V 6KA DISC 17MMB72214R2321K101VARISTOR 510V 6KA DISC 17MM320V420V459V890 - ImmediateView Details
VARISTOR 240V 6KA DISC 17MMB72214R2151K101VARISTOR 240V 6KA DISC 17MM150V200V216V1220 - ImmediateView Details
VARISTOR 430V 10KA DISC 23MMB72220R2271K101VARISTOR 430V 10KA DISC 23MM275V350V387V670 - ImmediateView Details
VARISTOR 510V 10KA DISC 23MMB72220R2321K101VARISTOR 510V 10KA DISC 23MM320V420V459V710 - ImmediateView Details
VARISTOR 205V 10KA DISC 23MMB72220W2131K101VARISTOR 205V 10KA DISC 23MM130V170V184.5V718 - ImmediateView Details
VARISTOR 430V 10KA DISC 23MMB72220W2271K101VARISTOR 430V 10KA DISC 23MM275V350V387V709 - ImmediateView Details
VARISTOR 510V 10KA DISC 23MMB72220W2321K101VARISTOR 510V 10KA DISC 23MM320V420V459V1010 - ImmediateView Details
VARISTOR 470V 10KA DISC 23MMB72220R2301K101VARISTOR 470V 10KA DISC 23MM300V385V423V680 - ImmediateView Details
VARISTOR 205V 10KA DISC 23MMB72220R2131K101VARISTOR 205V 10KA DISC 23MM130V170V184.5V719 - ImmediateView Details
VARISTOR 240V 10KA DISC 23MMB72220R2151K101VARISTOR 240V 10KA DISC 23MM150V200V216V689 - ImmediateView Details
VARISTOR 510V 6KA DISC 17MMB72214W2321K101VARISTOR 510V 6KA DISC 17MM320V420V459V950 - ImmediateView Details
VARISTOR 620V 6KA DISC 17MMB72214W2381K101VARISTOR 620V 6KA DISC 17MM385V505V558V850 - ImmediateView Details
VARISTOR 390V 10KA DISC 23MMB72220R2251K101VARISTOR 390V 10KA DISC 23MM250V320V351V707 - ImmediateView Details
Published: 2018-10-16