Advanced Monitoring, Diagnostics, Remote Indication and Testing of SPDs Connected to Telecommunications and Signalling Networks

To protect telecommunications and signalling networks efficiently against man-made and lightning induced surges, reliable surge protective devices (SPDs) are needed. Sometimes SPDs get exposed to voltages and currents beyond their design limits. This can cause overheating in certain applications with relatively high prospective short-circuit currents. For the protection against overheating, new sophisticated thermal disconnect devices and new short-circuiting mechanisms got designed. During their commercial lifetime SPDs can degrade. It's highly desirable to monitor the ”State of Health” of SPDs in a way that ageing SPDs can be detected reliably. This allows to replace SPDs during preventive maintenance. In this paper advanced approaches to ”online” and ”offline” monitoring and to testing of SPDs are discussed - including Smart SPDs with integrated advanced monitoring features, network connectivity, cloud-based ”State of Health” evaluation and cloud-based monitoring of surge impulses.