DEHNguard ME DC Y 950 FM three-pole, modular, plug-in combined arrester Type 1+2 for direct current applications with mechanical operating / fault state indication and UL approval Arrester Type 1+2 analogous to EN 61643-11, Y circuit consisting of leakage-current-free varistor gas discharge tube technology. DC switching device DCD specifically for use in DC current circuits up to 950 V.