Mersen’s TPMOV technology eliminates common failure modes that occur in the field with standard metal oxide varistors. Internally each unit is comprised of a voltage clamping device and a disconnecting apparatus that monitors the status of the metal oxide disk, making the TPMOV surge suppression component a fail-safe device. In the event of an overvoltage breakdown, the metal oxide disc is securely disconnected from the system power by an arc shield. Upon failure, the TPMOV surge suppression component is also equipped with a visual pin indicator as well as a normally open micro-switch, providing remote indication if applicable.