What is a Varistor?
A varistor is a surge-protecting electronic component with an electrical resistance that varies with the applied voltage.
Varistor Suppliers In South Africa
How do I choose a varistor?
Therefore, in general, when we select a varistor, the flow capacity should be calculated by pressing the 10 to 100 impacts in the rating curve of the varistor surge lifetime.
The actual surge current passed is about 30% of the maximum impact current.
How do you know if a varistor is good?
The most common method of testing a varistor is resistance or voltage measurement. In this type of test, the varistor is placed in a circuit and the resistance or voltage is measured across it.
This can be done using a digital multimeter.
What happens when a varistor fails?
The failure mode for TNR Ceramic Varistors is generally short mode.
If a large surge current is applied, it may lead to an instantaneous short resulting in violent explosion and scattering that leaves the circuit open.
What voltage is a varistor for mains?
For 230 V mains a varistor of 275 V clamping voltage is a good choice. This rating is given in joules and shows how much energy the varistor can absorb.