{"product_id":"honeywell-rm7890a1031-relay-module","title":"Honeywell RM7890A1031 Relay Module","description":"\u003cp\u003eConfigured for automatic burner sequence execution and primary flame supervision in 7800 SERIES combustion platforms, the \u003cstrong\u003eHoneywell RM7890A1031\u003c\/strong\u003e (\u003cstrong\u003eRM7890A1031\u003c\/strong\u003e Burner Control Unit) provides direct physical\/electrical execution. It mounts directly to a Q7800 wiring subbase to supervise intermittent pilot ignition, extended pilot flame establishing sequences, safety interlock inputs, and main fuel valve circuit outputs across industrial single-burner installations.\u003c\/p\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eRM7890A1031\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eHoneywell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eUSA \/ Mexico\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e3.00 lbs (1.36 kg)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e127 mm x 127 mm x 133 mm (with Q7800 subbase)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e-40 deg C to +60 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e10 W nominal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSupply Voltage\u003c\/td\u003e\n\u003ctd\u003e120 VAC (+10%, -15%), 50\/60 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePilot Type\u003c\/td\u003e\n\u003ctd\u003eIntermittent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePilot Flame Establishing Period\u003c\/td\u003e\n\u003ctd\u003eFixed 30 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMain Flame Establishing Period\u003c\/td\u003e\n\u003ctd\u003eIntermittent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eProcess Control and DCS Interface Features\u003c\/h3\u003e\n\u003cp\u003eThe module relies on channel-to-channel isolation to decouple low-voltage micro-ampere flame sensor inputs from 120 VAC output switching logic. Operating telemetry, sequence state timing, and real-time diagnostic lockout codes pass through the front-facing serial ControlBus port, enabling direct data integration into supervisory DCS networks and industrial PLCs without compromising safety circuit integrity or loop isolation.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: What is the primary operational distinction of the RM7890A1031 compared to standard 7800 SERIES primary relay modules?\u003c\/p\u003e\n\u003cp\u003eA: The RM7890A1031 features a fixed 30-second pilot flame establishing period to accommodate specialized industrial pilot burner ignition requirements.\u003c\/p\u003e\n\u003cp\u003eQ: Is a plug-in purge timer card required to operate the RM7890A1031?\u003c\/p\u003e\n\u003cp\u003eA: No, the RM7890A1031 functions as a non-purge primary control module, but it still requires a plug-in flame signal amplifier and a compatible Q7800 subbase for full system operation.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003eDisconnect and isolate all line-voltage AC power feeds connected to the Q7800 subbase prior to installing or removing the module.\u003c\/li\u003e\n\u003cli\u003eCheck subbase terminal headers to ensure clean card-edge contacts and proper physical alignment.\u003c\/li\u003e\n\u003cli\u003eAlign the rear connector of the RM7890A1031 straight into the subbase socket and secure the captive retaining screws to prevent loose terminal connection under field vibration.\u003c\/li\u003e\n\u003cli\u003eMaintain a physical separation of at least 150 mm between low-voltage flame signal lines, serial ControlBus wiring, and high-voltage ignition transformer leads.\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"Honeywell","offers":[{"title":"Default Title","offer_id":45396608909427,"sku":"RM7890A1031","price":233.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0644\/4348\/2227\/files\/RM7898A1000_2_98aea678-48d5-4e0c-986f-465d40c4652c.png?v=1787623847","url":"https:\/\/www.dcssupplier.com\/products\/honeywell-rm7890a1031-relay-module","provider":"DcsSupplier Limited","version":"1.0","type":"link"}