... surge protection device (in short: SPD, alias: surge suppressor, surge arrester) is suitable for TN-S, TN-C-S, TT, ... and Installation PositionIt's suitable for D grade (class) lightning protection, CAN-D20 series surge protection device according to IEC61643 ... 4P-385, 8 pieces.Main Technical Parameters Surge Protection Device CAN-D20Max. Continuous Operating Voltage Uc (V~)275V320V385V420V440VVoltage ...