{"product_id":"rex-521-abb-feeder-protection-relay-in-stock","title":"REX 521 | ABB | Feeder Protection Relay In Stock","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eREX 521 Feeder Protection Relay\u003c\/strong\u003e is designed for the protection, control, measurement, and supervision of medium voltage networks. It also protects large and medium-sized three-phase AC motors in circuit breaker-controlled motor drives. This relay provides robust protection for both utility substations and industrial power distribution systems. Though it is no longer an active product since 2012, the REX 521 is still used in legacy installations.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMulti-Functional Protection:\u003c\/strong\u003e The relay offers protection for feeders, motors, and substations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInput Compatibility:\u003c\/strong\u003e Supports conventional current and voltage transformers, as well as hardware versions for current and voltage sensors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePre-configured Settings:\u003c\/strong\u003e Pre-made standard configurations make the unit adaptable to different network types.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtended Functions:\u003c\/strong\u003e Provides efficient protection with extended measuring, supervision, and control functionalities.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSingle Busbar Solutions:\u003c\/strong\u003e Suitable for single busbar configurations, with a single circuit breaker for various protections.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNetwork Compatibility:\u003c\/strong\u003e Medium voltage networks, radial isolated neutral, resonant earthed, solidly earthed, and resistively earthed systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMotor Protection:\u003c\/strong\u003e Designed for large and medium-size three-phase AC motors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTransformer Protection:\u003c\/strong\u003e Can be used as backup protection for power transformers and high-voltage line-protection relays.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInputs:\u003c\/strong\u003e Compatible with conventional current and voltage transformers, with a version available for current and voltage sensors.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ABB","offers":[{"title":"Default Title","offer_id":41881576800323,"sku":"REX521","price":300.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/5810\/3107\/files\/REX521_2.png?v=1741329275","url":"https:\/\/www.plcdcspro.com\/products\/rex-521-abb-feeder-protection-relay-in-stock","provider":"PLC DCS Pro Ltd.","version":"1.0","type":"link"}