how to select VARISTORS FOR SURGE PROTECTION

Determine the maximum voltage rating required: The voltage rating of the varistor should be higher than the highest expected voltage that the device will experience during operation.

Determine the maximum surge energy that the device may experience: This will help determine the energy absorption capability of the varistor.

Select the appropriate varistor type: The most common types of varistors are metal oxide varistors (MOV) and silicon carbide varistors (SIC). MOVs are commonly used for low and medium voltage applications, while SICs are used for high voltage applications.

Determine the clamping voltage: The clamping voltage is the voltage at which the varistor starts conducting and dissipating energy. It should be less than the maximum allowed voltage for the protected equipment.

Check the response time: The response time is the time it takes for the varistor to start conducting and dissipating energy. It should be fast enough to protect the equipment from the surge.

Check the temperature rating: The varistor should be able to withstand the maximum operating temperature of the equipment.

Check the physical size and mounting options: The varistor should fit in the equipment and be able to be mounted in a suitable location.

Consider the manufacturer's reputation and reliability: Select a reputable manufacturer with a proven track record in producing quality surge protection devices.