{"product_id":"abb-rex521-motor-protection-relay","title":"ABB REX521 Motor Protection Relay","description":"\u003ch3\u003eProduct Overview\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eABB REX521\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis a high-performance, multi-functional protection relay engineered for the rigorous demands of medium-voltage networks. It provides a comprehensive suite of protection, control, measurement, and supervision functions, making it an ideal choice for incoming\/outgoing feeders and asynchronous motor drives.\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eProtection Suite:\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003eOvercurrent (OC) and Earth Fault (EF) Protection\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eDirectional Overcurrent (DO) Protection\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eOver\/Under Voltage (OV\/UV) Monitoring\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eThermal Overload Protection specifically tuned for motors\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eRelay Applications:\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003eIncoming and Outgoing Feeders\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eLarge and medium-sized three-phase AC motors\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eBack-up protection for transformers and HV lines\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eSystem Compatibility:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eSuitable for solidly, resistively, and resonant earthed (Petersen coil) systems\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eOperating Voltage:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e24V DC, 48V DC, or 110V DC (Model dependent)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eEnvironmental:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eExtreme temperature tolerance from -40°C to +70°C\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eInterfaces:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eIntegrated HMI with multi-line LCD and status LEDs\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eCompliance:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eFully compliant with IEC 60255 and IEC 61850 standards\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eKey Features \u0026amp; Engineering Advantages\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eHardware Versatility:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThe availability of sensor-compatible versions allows for the use of Rogowski coils and resistive voltage dividers, offering linear measurement across a wider range than traditional CTs.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eRugged Reliability:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eDesigned to operate in harsh environments, its wide temperature range and high humidity tolerance ensure stable performance in unconditioned industrial substations.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eStreamlined Integration:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ePre-made standard configurations significantly reduce engineering time, allowing the relay to be quickly adapted to various grid grounding philosophies and network types.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eComprehensive Supervision:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eContinuous self-supervision of both internal hardware and software prevents silent failures, ensuring that protection is always ready when a fault occurs.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ABB","offers":[{"title":"Default Title","offer_id":46799788605630,"sku":"REX521","price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0725\/1145\/5422\/files\/screenshot_2026-05-08_11-36-49.png?v=1778211561","url":"https:\/\/www.autooiltech.com\/products\/abb-rex521-motor-protection-relay","provider":"AutoOilTech Limited","version":"1.0","type":"link"}