Surge arrester type 2 requirement class C, UC 350V Protective modules plug-in 1-pole, L-N circuit with remote indication Surge protection devices for protection against overvoltages in electrical installations. Siemens surge protection devices, as an important part of the SENTRON protection components for electrical installations, provide effective protection against lightning and overvoltages due to atmospheric influences or switching operations. Convenient mounting and connection technology as well as a consistent design are the hallmarks of the device family. Whether for infrastructure or industrial requirements, Siemens offers surge protection devices for all applications and every field of use. The Siemens surge protection devices are characterized above all by: 1. effective investment and system protection against lightning and surges. 2. the right lightning and surge protection for every application (type 1 to 3). 3. remote signalling contact for external upload of status indication. 4.