In order to investigate the current distribution characteristics of multi-column arresters under long duration overvoltage impacts

varistors from two manufactures were tested with the 60 ms square current impact in this paper. The research results show that

with long duration overvoltage impacts

the current disparity is much different with that acquired from the normal test; the current disparity may increase or decrease with the increase of temperature; the current disparity is not only related to the positive and negative of the temperature coefficient of varistor resistance

but also the difference of the coefficient between the columns; in case of matching the varistors

we should not only considering the U

1mA

reference voltage and residual voltage under standard lightning impulse

the temperature characteristics of the current disparity shou

ld also be considered. The research results can provide reference for the valve match selection of multi-column valve parallel shunt arrester.