Devices, systems and methods to monitor and report wiring status for zone selective interlocking cables

摘要

Various embodiments of the present invention are directed to a first trip unit that is configured to be coupled to a power distribution system arranged in a Zone Selective Interlocking (ZSI) arrangement. The first trip unit includes an Input/Output circuit including a ZSI input terminal and a ZSI output terminal, a heartbeat signaling module configured to transmit a second signal to a second trip unit in a lower-level zone than the first trip unit, responsive to the normal condition, a first monitoring module configured to monitor a first signal received by the first trip from a third trip unit in a higher-level zone, responsive to the normal condition, and a second monitoring module configured to detect the fault condition. Related systems, devices, and methods are also described.