In order to use surge arrester sizing, user should add surge arrester element into the scheme. Surge arrester icon is . Double click on this icon and in the properties window push on the “Surge arrester sizing” button. Functionality is currently limited for cables protection.
Software will automatically take information about insulation level of the equipment that is connected to the “Protected object”. Therefore, to successfully use surge arrester sizing, user should specify “Rated voltage” parameters of the equipment. Explanation of markings:
– continuous operating voltage ( for isolated neutral networks and for grounded neutral networks, where is system voltage);
– rated voltage 1,2 to 1,5 times bigger then , coefficient depend on the equipment type (motor, transformer, generator, line and etc.);
– protective level lighting impulse – surge arrester characteristic of 8/20 us wave;
– basic insulation level (standard values are provided in IEEE C62.21);
– line equivalent wave impedance;
– max discharge current;
– arrester residual voltage during line discharge;
– energy absorbed by arrester;
– protection margins according to IEEE C62.21;
– switching voltage due to the fault;
Module calculations will depend on the selected lightening protection level LPL. Lightening protection level can be changed in Settings > Calculation > Short Circuit > Lightening protection level.
. Double click on this icon and in the properties window push on the “Surge arrester sizing” button. Functionality is currently limited for cables protection.
– continuous operating voltage (
for isolated neutral networks and 
for grounded neutral networks, where 
– rated voltage 1,2 to 1,5 times bigger then 
– protective level lighting impulse – surge arrester characteristic of 8/20 us wave;
– basic insulation level (standard values are provided in IEEE C62.21);
– line equivalent wave impedance;
– max discharge current;
– energy absorbed by arrester;
– protection margins according to IEEE C62.21;
– switching voltage due to the fault;