Type 1 surge arrester, requirement class B, UC 350V, plug-in protection modules, 3-pole, 3+0 circuit for TNC systems with remote indication. Surge protection devices to protect against surges in electrical installations. Siemens surge protection devices are an essential component of the SENTRON protection portfolio for electrical installations, providing effective protection against lightning and surges caused by atmospheric influences or switching operations. Convenient mounting and connection technology, along with a consistent design, characterize this device family. Whether for infrastructure or industrial applications, Siemens offers surge protection devices for all applications and every area of use. Siemens surge protection devices are particularly distinguished by: 1. Effective investment and equipment protection against lightning and surges. 2. The right lightning and surge protection for every application (Type 1 to 3). 3. Remote contact for external status upload.