SPD is an electronic device that protects electronic equipment, instruments, and communication connections against unauthorized access. SPD can conduct the shunt in a very short time when the peak current or voltage is rapidly generated in the electrical circuit or communication line owing to external interference, preventing surge damage to other equipment in the circuit.

DC SPD is ideal for AC 50/60Hz power supply systems with a rated voltage of 220 V to 380 V, and can be used to protect against indirect and direct lightning strikes, as well as other types of sudden overvoltage surges, in the home, tertiary industry, and industrial settings.