{"product_id":"honeywell-rm7890b1048-control-module","title":"Honeywell RM7890B1048 Control Module","description":"\u003cp\u003eConfigured for automatic burner sequence control and primary flame monitoring in 7800 SERIES combustion assemblies, the \u003cstrong\u003eHoneywell RM7890B1048\u003c\/strong\u003e (\u003cstrong\u003eRM7890B1048\u003c\/strong\u003e Burner Control Unit) provides direct physical\/electrical execution. It mounts directly to a Q7800 wiring subbase to supervise intermittent pilot ignition, main flame establishing periods, safety interlock loops, and line-voltage fuel shutoff valve outputs.\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\u003eRM7890B1048\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\u003eMemory Type\u003c\/td\u003e\n\u003ctd\u003eNonvolatile Memory\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 4 s or 10 s\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 provides channel-to-channel isolation between low-voltage micro-ampere flame detection circuits, internal microprocessors, and line-voltage switching relays. System status, real-time flame voltage telemetry, and historical lockout codes pass through the integrated serial ControlBus interface to supervisory DCS platforms or plant PLCs without causing signal degradation or introducing interference to critical safety trip loops.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: What protection does the nonvolatile memory provide in the RM7890B1048?\u003c\/p\u003e\n\u003cp\u003eA: Nonvolatile memory retains all critical lockout history, sequence execution status, and diagnostic operational fault data during a complete loss of primary input power.\u003c\/p\u003e\n\u003cp\u003eQ: Is a separate plug-in purge card required to operate the RM7890B1048?\u003c\/p\u003e\n\u003cp\u003eA: No, unlike purge-dependent 7800 SERIES modules, the RM7890B1048 operates as a non-purge burner control unit while still requiring a plug-in flame signal amplifier and Q7800 subbase.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003eEnsure all 120 VAC incoming line power feeds to the Q7800 wiring subbase are completely isolated before mounting or removing the module.\u003c\/li\u003e\n\u003cli\u003eInspect the rear card-edge contacts to confirm terminals are aligned straight and clean prior to seating into the subbase receptacle.\u003c\/li\u003e\n\u003cli\u003ePush the module firmly onto the subbase and tighten the central captive retaining screws to prevent loose contact under operational industrial vibration.\u003c\/li\u003e\n\u003cli\u003eRoute flame signal sensor lines and ControlBus communication cables in dedicated conduits separated by at least 150 mm from high-voltage ignition transformer leads.\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"Honeywell","offers":[{"title":"Default Title","offer_id":45396608286835,"sku":"RM7890B1048","price":233.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0644\/4348\/2227\/files\/S7800A1001_a76c6250-09e7-43ff-8c58-dc2c93b3aeb3.png?v=1787623881","url":"https:\/\/www.dcssupplier.com\/products\/honeywell-rm7890b1048-control-module","provider":"DcsSupplier Limited","version":"1.0","type":"link"}