{"product_id":"fdx-551r-notifier-rate-of-rise-temperature-sensor","title":"FDX-551R | Notifier Rate-of-Rise Temperature Sensor","description":"\u003ch4\u003eDescription \u003c\/h4\u003e\n\u003cp\u003eThe FDX‑551R is a plug-in, intelligent analog rate-of-rise temperature sensor in Notifier’s legacy product line, designed to detect rapid temperature increases indicative of fire.\u003c\/p\u003e\n\u003cp data-start=\"284\" data-end=\"574\" class=\"\"\u003e \u003c\/p\u003e\n\u003cp data-start=\"284\" data-end=\"574\" class=\"\"\u003e \u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications \u003c\/h4\u003e\n\u003ctable style=\"width: 99.964%; height: 108px;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"height: 19.6px;\"\u003e\n\u003ctd style=\"width: 29.2337%; height: 19.6px;\"\u003e\u003cstrong\u003eCondition\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%; height: 19.6px;\"\u003eNew\/Never Used Surplus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 19.6px;\"\u003e\n\u003ctd style=\"width: 29.2337%; height: 19.6px;\"\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%; height: 19.6px;\"\u003eNotifier\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 19.6px;\"\u003e\n\u003ctd style=\"width: 29.2337%; height: 19.6px;\"\u003e\u003cstrong\u003eCategory\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%; height: 19.6px;\"\u003e\u003cspan\u003eFire Safety\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 19.6px;\"\u003e\n\u003ctd style=\"width: 29.2337%; height: 19.6px;\"\u003e\u003cstrong\u003ePart Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%; height: 19.6px;\"\u003eFDX-551R\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 19.6px;\"\u003e\n\u003ctd style=\"width: 29.2337%; height: 19.6px;\"\u003e\u003cstrong\u003eSubcategory\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%; height: 19.6px;\"\u003e\u003cspan\u003eFire Alarm Systems\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eDevice Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eFire Detector – Heat Sensor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eDetection Method\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eRate-of-Rise (≥ 15°F\/min)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eSensing Components\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eDual Thermistors\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eDetection Modes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eRate-of-Rise, Fixed Temperature, Fixed High Temperature\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eCommunication Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eAnalog Addressable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eAddress Configuration\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eRotary DECADE switches (01–99)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eOperating Voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003e15–28 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eMounting Base\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eUses common sensor base\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eRemote LED Output\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eStandard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eVisual Indicators\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eDual 360° visible LEDs (blink on poll, steady on alarm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eTest Feature\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eBuilt-in magnetic test switch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eOptional Base Features\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eSupports Relay, Isolator, and Sounder bases\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eTamper-Resistance\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003eNoise Immunity\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003eStable communication with high noise immunity\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.2337%;\"\u003e\u003cstrong\u003e\u003cspan\u003eWeight\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 70.6331%;\"\u003e\u003cspan\u003e0.25 kgs\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch4\u003eInformation About FDX-551R\u003c\/h4\u003e\n\u003cp\u003eThe FDX‑551R is part of Notifier’s legacy line of intelligent rate-of-rise heat detectors, engineered for responsive detection of rapid temperature increases in fire alarm systems. Designed to detect a temperature rise exceeding 15°F per minute, it also features a fixed-temperature threshold for reliable activation under fast-developing fire conditions. Compatible with Notifier’s addressable analog control panels, the FDX‑551R communicates real-time data and status updates while maintaining low standby current and high noise immunity. Its plug-in design, 360° visible LED indicators, and tamper-resistant features make it an ideal solution for commercial and industrial environments requiring thermal detection without the sensitivity of smoke-based sensing.\u003c\/p\u003e\n\u003ch4\u003eKey Features:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eRate-of-Rise Detection: Activates when ambient temperature increases more than 15°F per minute, providing early warning of fast-growing fires.\u003c\/li\u003e\n\u003cli\u003eFixed Temperature Backup: Includes a static alarm threshold (typically 135°F) for reliable activation in heat-intensive conditions.\u003c\/li\u003e\n\u003cli\u003eAnalog Addressable Operation: Communicates real-time thermal data to Notifier panels for detailed event tracking and system diagnostics.\u003c\/li\u003e\n\u003cli\u003eDual Thermistor Technology: Provides accurate, stable temperature sensing with minimal false alarms.\u003c\/li\u003e\n\u003cli\u003e360° LED Visibility: Twin LEDs offer alarm indication from any viewing angle; configurable blink for polling.\u003c\/li\u003e\n\u003cli\u003ePlug-In Base Compatibility: Easily mounts onto standard Notifier bases (e.g., B501 or BX-501), supporting rapid installation and servicing.\u003c\/li\u003e\n\u003cli\u003eMagnetic Test Capability: Built-in switch supports activation using an external magnet for simplified functional testing.\u003c\/li\u003e\n\u003cli\u003eTamper-Resistant Design: Prevents unauthorized removal or manipulation without tools.\u003c\/li\u003e\n\u003cli\u003eOptional Base Features: Supports relay, isolator, or sounder bases for enhanced system integration.\u003c\/li\u003e\n\u003cli\u003eEnvironmental Ratings: Operates from 32°F to 100°F (0°C to 38°C) with up to 93% non-condensing humidity.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe Notifier FDX‑551R provided fast and intelligent thermal detection in addressable systems where smoke detection may not be suitable. Though discontinued, it remains a reliable legacy solution in many installations and is functionally replaced in modern systems by devices like the FST-951R or NFX-TDIFF-IV.\u003c\/p\u003e","brand":"Notifier","offers":[{"title":"Default Title","offer_id":49105263689984,"sku":"FDX-551R","price":307.23,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0388\/5331\/2557\/files\/fe313350961845d48fc10a06f707ba2f.jpg?v=1785543769","url":"https:\/\/alotechparts.com\/products\/fdx-551r-notifier-rate-of-rise-temperature-sensor","provider":"Alo Tech Solutions","version":"1.0","type":"link"}