YCS6-D series Surge Protection Device is suitable for TT, IT, TN-S, TN-C and TN-C-S, the power supply system with the rated voltage up to 230/400V and AC 50/60Hz. Its design corresponds to IEC61643-1. The product is usually installed in the incoming line low voltage distribution box of the building, and it can release 20kA lightning stroke current. The lightning current SPD protection with protection level: III is applied to the Equipotential bonding when the lightning strike. YCS6-D Device should be installed in the boundary of LPZ1, LPZ2 and LPZn, usually in front of the residential distribution box, computer center, informational equipment, electronic equipment and controlling equipment or in the nearest socket box.