Selection Of Varistor
Feb 20, 2021
Before choosing a varistor, you should first understand the following related technical parameters: Nominal voltage refers to the voltage value across the varistor under the specified temperature and DC current. Leakage current refers to the current value flowing in the varistor when the maximum continuous DC voltage is applied under the condition of 25°C.
Grade voltage refers to the voltage peak value that appears at both ends of the varistor when it passes 8/20 grade current pulses. The flow rate is the peak current when the specified pulse current (8/20μs) waveform is applied.
Surge environmental parameters include the maximum surge current Ipm (or the maximum surge voltage Vpm and the surge source impedance Zo), the surge pulse width Tt, the minimum time interval Tm between two adjacent surges, and the preset value of the varistor During the working life, the total number of surge pulses N etc.
