Protection of electronic equipment inside buildings: A hidden source of damages

This paper shows that the criteria for the installation of surge protective devices (SPD) in power distribution panels as prescribed in standards on lightning protection and on low-voltage electrical installations may not prevent damages of sensitive electronic equipment, regardless of the protection level of the SPD and ground impedance. This is due to a not so evident source of damages related to incidental flashovers occurring between the equipment frame and grounded structures such as the floor underneath. This paper investigates this issue from experimental and theoretical approaches and provides some procedures in order to avoid such type of damages.