Metal Oxide Varistor (MOV) as one nonlinear resistance element is mainly made of zinc oxide (ZnO), which has very high surge capacity and big nonlinear coefficient. Below the threshold voltage, its resistance is very high, nearly no current flows through, but above the threshold voltage, the resistance reduces sharply, huge current can be discharged. Due to this characteristic, varistor as a protection component in electronic and electrical equipment can absorb abnormal over-voltage and lightning surge.
SETsafe | SETfuse varistor is with High Surge Current Density, Low Clamping Voltage, and Good Surge Capacity. It can also be customized as required.
● Smart grid Industrial control equipment Security
● Military industry aerospace illumination
Nominal Varistor Voltage
Voltage, at specified d.c. current used as a reference point in the component characteristic.
Measuring at 75% of varistor voltage
Upper Category Temp.
Max. ambient temp. for which a varistor has been designed to operate continuously.
Lower Category Temp.
Minimum ambient temp. at which a varistor has been designed to operate continuously.
Max. Peak Current
Max. current per pulse, which may be passed by a varistor at an ambient temp. of 25 °C, for a given number of pulses.
Peak voltage developed across the varistor terminations under standard atmospheric conditions, when passing an 8/20 μs class current pulse.
Max. peak voltage, which may be applied under continuous operating conditions between the varistor terminations and any conducting mounting surface. (Applicable only to insulated varistors)
Capacitance across the MOV measured at a specified frequency and voltage.
Max. Continuous a.c. Voltage
Max. a.c. r.m.s. voltage of a substantially sinusoidal waveform (less than 5% total harmonic distortion) which can be applied to the component under continuous operating conditions at 25 °C.
Max. Continuous d.c. Voltage
Max. d.c. voltage (with less than 5% ripple) which can be applied to the component under continuous operating conditions at an ambient temp. of 25 °C.
Nominal Discharge Current
Crest value of the current through the SPD having a current waveshape of 8/20 µs.
Max. Discharge Current
Crest value of a current through the SPD having an 8/20 µs waveshape and magnitude according to the manufacturers specification. Imax is equal to or greater than In.
1. Varistor must operated in the specified ambient temp.
2. Do not clean the varistor with strong polar solvent such as ketone, esters, benzene and halogenated hydrocarbon.
3. Please do not apply severe vibration, shock or pressure to MOV.
4. Please fix lead wires when bending or cutting. The distance between the bending point and the sealing of MOV shall be greater than 2 mm.
If varistor is visually damaged,please replace it.
1. Storage Temp. Range: (-40 to +125) °C
2. Relative Humidity : ≤75% RH
3. Height Above Sea Level :< 2000 m
Do not store the MOV at the high temp., high humidity or corrosive gas environment, to avoid influencing the solder-ability of the lead wires, the product shall be used up within 1 year after receiving the goods.
1. Varistor should neither be exposed to the open air, nor direct sunshine.
2. Varistor should avoid rain, water vapor or other condition of high temp. and high humidity.
3. Varistor should avoid sand dust, salt spray, or other harmful gases.
Max. Typical Capacitance of Varistor
The typical capacitance of varistor is listed in the specifications. Designers may refer to it when designing MOV in high frequency circuit.
Do not knock MOV when installing, to avoid mechanical damage.
Wave Soldering Parameters
The wave soldering parameters are for reference only. When MOV is for practice use, some related validation is recommended.