DUPLICATION PROTECTION SYSTEM HAVING AUTO SWITCHABLE SPD

The present invention relates to a duplication protection system of SPD capable of automatic conversion which stably prevents a surge current by comprising multiple surge protectors (30) and connecting the other surge protector (30) if one surge protector (30) is not work. A major composition of the present invention comprises; a current inserting part (10) which receives a current inserted into the inside form outside while being located inside a case; a current discharging part (20) which is located within the case and supplies the current to an external electronic device; the surge protectors (30) which are formed within the case with a parallel mode and selectively receives the current of the current inserting part (10); a conversion switch part (50) which selectively connects one among the multiple surge protectors (30) to the current inserting part (10); and a surge protector checking part (70) which checks the operating state of the surge protector (30) connected through the conversion switch part (50) and provides a replacing signal to the conversion switch part (50) so that the other surge protector (30) is connected to the current inserting part (10) if it is determined that the connected surge protector (30) breaks out. [Reference numerals] (10) Current inserting part;(20) Current discharging part;(30) Surge protector;(40) Conversion switch part;(50) Voltage switch part;(60) Voltage measurement part;(70) surge protector checking part;(80) Display part;(90) Communication part