LYD1-C series surge protective device(SPD) is suitably used in the IT, TT, TN-C, TN-S, TN-C-S and Low-voltage AC power distribution system, rated voltage up to 380V, to protect from direct and indirect lighting impulse and other transient over voltage. SPD has two protection modes: MC and MD.

SPD as only one side of terminals, able to prevent from being electric touching, indoor fixedly mounted, limiting voltage.
SPD has built-in disconnector, when SPD is invalid due to overheating or break down, the disconnector can automatically separate SPD from the network, meanwhile send an indication signal. The visible window show white color in normal service, if to be separated from network, it will show red color
1P+N, 2P+N, 3P+N SPD consist of 1P, 2P, 3P SPD and NPE neutral and earthing protection modules, used in the power supply system of TT, TN-S and so on.
Secondary protection for in line.
White Normal; Red, invalidation