Industrial RXIDF 2H RK 473 005-CA Overcurrent Relay

The RXIDF 2H RK 473 005-CA Overcurrent Relay is a plug‑in, AC time‑overcurrent protection module from ASEA (ABB lineage) designed to mount in compatible protection relay racks and monitor line current via a CT secondary. As part of the RXIDF 2H family, it provides inverse‑time protection by detecting CT secondary current relative to a programmable pickup; once fault current exceeds the pickup, the relay delays tripping proportionally to fault magnitude to coordinate with other protection devices and minimize nuisance trips. The unit incorporates a reconnectible current rating (In) selector that must be matched to the connected CT secondary rating to set the pickup accurately; installers commonly configure CTs with a 5 A secondary (for example, 600/5 A) to ensure proper coordination and selectivity in feeders and transformers. The 473‑005‑CA variant identifies a specific RK 473 model, and, as part of ASEA's protection‑relay portfolio, it is used for protection of feeders, transformers, and motor circuits in industrial power systems where legacy RXIDF hardware remains in service.