{"product_id":"honeywell-51120841-101-spdt-control-relay","title":"Honeywell 51120841-101 SPDT Control Relay","description":"\u003cp\u003eThe \u003cstrong\u003eHoneywell 51120841-101\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e51120841\u003c\/strong\u003e SPDT Control Relay, operates as a dedicated hardware component for physical circuit isolation and load switching within industrial control systems. This MR series assembly establishes electromechanical contact switching pathways to route pilot-duty signals and power circuits based on external control voltage commands.\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\u003e51120841-101\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\u003eSeries\u003c\/td\u003e\n\u003ctd\u003eMR Series\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eUnited States\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.2 lbs (0.09 kg)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e2 in x 2 in x 1.5 in (5.08 cm x 5.08 cm x 3.81 cm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003eStandard industrial control enclosure environmental limits\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eElectromechanical Control Relay\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eContact Arrangement\u003c\/td\u003e\n\u003ctd\u003eSPDT (Single Pole, Double Throw), Form C execution\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eContact Current Rating\u003c\/td\u003e\n\u003ctd\u003e10 A maximum resistive load handling\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoil Control Voltages\u003c\/td\u003e\n\u003ctd\u003eMulti-voltage input pins: 24 V AC\/DC, 115 V AC, or 230 V AC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDC Operating Range\u003c\/td\u003e\n\u003ctd\u003e18 to 30 VDC continuous coil activation limits\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStatus Indicator\u003c\/td\u003e\n\u003ctd\u003eIntegrated red LED (Illuminates upon active coil energization)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Configuration\u003c\/td\u003e\n\u003ctd\u003eIntegrated hardware for DIN-rail or flat panel mounting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eProcess Control Instrumentation and DCS Communication\u003c\/h3\u003e\n\u003cp\u003eThe control relay acts as a robust physical isolation barrier between sensitive low-voltage microprocessors and high-voltage field actuator elements. When integrated alongside digital outputs from a distributed control system, the module isolates the logic card from inductive back-EMF spikes generated by large solenoids or motor starters.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: How does the multi-voltage coil terminal configuration operate without causing internal short circuits?\u003c\/p\u003e\n\u003cp\u003eA: The relay frame utilizes separate, dedicated physical terminal pins for each specific control voltage rating (24 V AC\/DC, 115 V AC, and 230 V AC). Electrical wiring must only be terminated to the single target voltage pin and common neutral\/ground pair required for the application; energizing multiple coil input pins concurrently will destroy the internal coil windings.\u003c\/p\u003e\n\u003cp\u003eQ: What is the mechanical state of the SPDT contacts when control power is lost to the module coil?\u003c\/p\u003e\n\u003cp\u003eA: The SPDT contact array utilizes a spring-return Form C architecture. Upon a total loss of coil control voltage, the internal armature immediately returns to its de-energized state, opening the Normally Open (NO) circuit path and closing the Normally Closed (NC) circuit path to execute a predictable fail-safe state.\u003c\/p\u003e","brand":"Honeywell","offers":[{"title":"Default Title","offer_id":47613948461246,"sku":"51120841-101","price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0725\/1145\/5422\/files\/screenshot_2026-06-08_11-50-59.png?v=1780890773","url":"https:\/\/www.autooiltech.com\/ar\/products\/honeywell-51120841-101-spdt-control-relay","provider":"AutoOilTech Limited","version":"1.0","type":"link"}