{"product_id":"honeywell-analytics-301-em-rfsa-us3-multi-zone-gas-detection-controller-with-modbus-communication","title":"Honeywell Analytics 301-EM-RFSA-US3 Multi-Zone Gas Detection Controller with Modbus Communication","description":"\u003cdiv data-is-intersecting=\"true\" data-turn-id-container=\"request-WEB:57a3c288-e5c2-4b7b-bbec-6ffbfcaecaa3-6\" class=\"\"\u003e\n\u003csection data-turn=\"assistant\" data-scroll-anchor=\"false\" data-testid=\"conversation-turn-14\" data-turn-id-container=\"request-WEB:57a3c288-e5c2-4b7b-bbec-6ffbfcaecaa3-6\" data-turn-id=\"request-WEB:57a3c288-e5c2-4b7b-bbec-6ffbfcaecaa3-6\" dir=\"auto\" class=\"text-token-text-primary w-full focus:outline-none has-data-writing-block:pointer-events-none [\u0026amp;:has([data-writing-block])\u0026gt;*]:pointer-events-auto R6Vx5W_threadScrollVars scroll-mb-[calc(var(--scroll-root-safe-area-inset-bottom,0px)+var(--thread-response-height))] scroll-mt-[calc(var(--header-height)+min(200px,max(70px,20svh)))]\"\u003e\n\u003cdiv class=\"text-base my-auto mx-auto pb-10 [--thread-content-margin:var(--thread-content-margin-xs,calc(var(--spacing)*4))] @w-sm\/main:[--thread-content-margin:var(--thread-content-margin-sm,calc(var(--spacing)*6))] @w-lg\/main:[--thread-content-margin:var(--thread-content-margin-lg,calc(var(--spacing)*16))] px-(--thread-content-margin)\"\u003e\n\u003cdiv class=\"[--thread-content-max-width:40rem] @w-lg\/main:[--thread-content-max-width:48rem] mx-auto max-w-(--thread-content-max-width) flex-1 group\/turn-messages focus-visible:outline-hidden relative flex w-full min-w-0 flex-col agent-turn\"\u003e\n\u003cdiv class=\"flex max-w-full flex-col gap-4 grow\"\u003e\n\u003cdiv data-turn-start-message=\"true\" class=\"min-h-8 text-message relative flex w-full flex-col items-end gap-2 text-start break-words whitespace-normal outline-none keyboard-focused:focus-ring [.text-message+\u0026amp;]:mt-1\" data-message-model-slug=\"gpt-5-5\" dir=\"auto\" data-message-id=\"fe0a3d2a-6c2a-4322-ae5b-5c5121259dcb\" data-message-author-role=\"assistant\" tabindex=\"0\"\u003e\n\u003cdiv class=\"flex w-full flex-col gap-1 empty:hidden\"\u003e\n\u003cdiv class=\"markdown prose dark:prose-invert wrap-break-word w-full light markdown-new-styling\"\u003e\n\u003ch4 data-start=\"0\" data-end=\"16\"\u003eDescription\u003c\/h4\u003e\n\u003cp data-start=\"17\" data-end=\"618\"\u003eThe Honeywell Analytics 301-EM-RFSA-US3 is a multi-zone gas detection controller and remote fan shut-off accessory engineered for industrial and commercial safety monitoring applications. Designed for integration with toxic gas, refrigerant, and combustion gas sensors, this controller provides advanced alarm handling, ventilation control, and Modbus communication for centralized gas monitoring systems. The Honeywell 301-EM-RFSA-US3 combines relay outputs, 4-20mA signal transmission, and programmable alarm functionality to support reliable environmental safety management in demanding facilities.\u003c\/p\u003e\n\u003cp data-start=\"17\" data-end=\"618\"\u003e \u003c\/p\u003e\n\u003cp data-start=\"17\" data-end=\"618\"\u003e \u003c\/p\u003e\n\u003ch4 data-start=\"17\" data-end=\"618\"\u003eTechnical Specifications\u003c\/h4\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCondition\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eNew\/Never Used Surplus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eHoneywell Analytics\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCategory\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eGas Detection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePart Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e301-EM-RFSA-US3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSubcategory\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eGas Detection Controllers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eProduct Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eRemote Fan Shut-Off Expansion Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCommunication\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eRS-485, Modbus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSignal Output\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4-20mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOutput Load\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1000Ω @ 24 VDC per sensor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eRelay Outputs\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4 DPDT Relays\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eRelay Rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e5A, 30 VDC \/ 250 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSupply Voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e22-27 VAC, 50\/60 Hz or 22-38 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePower Consumption\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e48 VA AC \/ 2A Max DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDisplay Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eBacklit LCD\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eAlarm Indicators\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eGreen, Red, Yellow, Amber LEDs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eAudible Alarm\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e65 dBA @ 3 ft\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMeasurement Range CO\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0-250 ppm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMeasurement Range NO2\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0-10 ppm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMeasurement Range Refrigerants\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0-1000 ppm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSensing Technology\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrochemical \/ Dual Infrared\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCalibration Interval\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e6 Months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eResponse Time\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e60 Seconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaximum Sensor Distance\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUp to 500 ft (160 m)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOperating Temperature\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e32°F to 100°F (0°C to 40°C)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOperating Humidity\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0% to 95% RH Non-Condensing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eEnclosure Rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eNEMA 1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eApprovals\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCSA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eApplication\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eRefrigeration, Laboratory, Transportation, Pharma, Medical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e7.99\"H x 11.02\"W x 2.76\"D\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e3.1 lb (1.4 kg)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp data-start=\"17\" data-end=\"618\"\u003e \u003c\/p\u003e\n\u003cp data-start=\"17\" data-end=\"618\"\u003e \u003c\/p\u003e\n\u003ch4 data-start=\"620\" data-end=\"642\"\u003eInformation About 301-EM-RFSA-US3\u003c\/h4\u003e\n\u003cp data-start=\"643\" data-end=\"1473\"\u003eThe 301-EM-RFSA-US3 is a Honeywell Analytics gas detection expansion module designed for use in refrigeration plants, laboratories, parking garages, transportation facilities, pharmaceutical environments, and cold storage applications. It supports monitoring of multiple gases including CO, NO2, and various refrigerants through electrochemical and infrared sensing technologies integrated with compatible remote transmitters and sensors. The controller features RS-485 Modbus networking, four programmable DPDT relays, audible and visual alarm indication, and multiple 24VDC outputs for activation of strobes and horns during hazardous gas events. Built for U.S. regulatory environments, this module offers simplified wiring, flexible multi-zone supervision, and dependable long-term performance in industrial gas safety systems.\u003c\/p\u003e\n\u003cp data-start=\"1475\" data-end=\"1492\"\u003e\u003cstrong\u003eKey Features:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"1493\" data-end=\"2650\"\u003e\n\u003cli data-start=\"1493\" data-end=\"1581\"\u003eMulti-Zone Gas Monitoring: Supports supervision of up to twenty gas detection zones.\u003c\/li\u003e\n\u003cli data-start=\"1582\" data-end=\"1700\"\u003eRemote Fan Shut-Off Function: Automatically activates ventilation and fan control systems during alarm conditions.\u003c\/li\u003e\n\u003cli data-start=\"1701\" data-end=\"1824\"\u003eWide Gas Compatibility: Detects CO, NO2, and multiple refrigerant gases including R11, R12, R22, R123, R125, and R134A.\u003c\/li\u003e\n\u003cli data-start=\"1825\" data-end=\"1930\"\u003eRS-485 Modbus Communication: Enables network integration with building automation and safety systems.\u003c\/li\u003e\n\u003cli data-start=\"1931\" data-end=\"2007\"\u003e4-20mA Signal Outputs: Provides analog output for each connected sensor.\u003c\/li\u003e\n\u003cli data-start=\"2008\" data-end=\"2113\"\u003eFour DPDT Relay Outputs: Includes programmable relays rated at 5A for alarm and control applications.\u003c\/li\u003e\n\u003cli data-start=\"2114\" data-end=\"2203\"\u003eIntegrated Audible Alarm: Features 65 dBA internal horn for local alarm notification.\u003c\/li\u003e\n\u003cli data-start=\"2204\" data-end=\"2282\"\u003eBacklit LCD Display: Allows clear system monitoring and status indication.\u003c\/li\u003e\n\u003cli data-start=\"2283\" data-end=\"2379\"\u003eVisual Alarm Indicators: Multi-color LED indication for normal, fault, and alarm conditions.\u003c\/li\u003e\n\u003cli data-start=\"2380\" data-end=\"2477\"\u003eStrobe and Horn Outputs: Includes three dedicated 24VDC outputs for external warning devices.\u003c\/li\u003e\n\u003cli data-start=\"2478\" data-end=\"2567\"\u003eFlexible Power Input: Operates from either AC or DC industrial control power sources.\u003c\/li\u003e\n\u003cli data-start=\"2568\" data-end=\"2650\"\u003eNEMA 1 Enclosure: Suitable for indoor industrial and commercial installations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2652\" data-end=\"2825\"\u003eThe 301-EM-RFSA-US3 delivers the reliability and precision required for industrial gas detection, refrigeration safety monitoring, and automated ventilation control systems.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003c\/div\u003e","brand":"Honeywell","offers":[{"title":"Default Title","offer_id":51568531570986,"sku":"301-EM-RFSA-US3","price":2897.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/0392\/4266\/files\/s-l1600_bb58232c-252f-45e3-8af0-a6ba24fe744c.webp?v=1779391593","url":"https:\/\/iqelectro.com\/products\/honeywell-analytics-301-em-rfsa-us3-multi-zone-gas-detection-controller-with-modbus-communication","provider":"IQElectro","version":"1.0","type":"link"}