Lightning arrester PRD1 Master. 1-pole+N, surge arrester class Type 1, nominal discharge current 25kA, highest continuous voltage (Uc) 350V, nominal voltage (Un) 230/400V, earthing system TT, TN-S. Surge protection for low-voltage systems. Installation takes place at the system's feed-in point. Arresters of the PRD1 25r and PRD1 Master series have plug-in protection modules. The PRD1 Master lightning arrester meets the following standards - IEC 61643-1 and EN 61643-11.