{"product_id":"1746-ow8-digital-contact-output-module-allen-bradley","title":"1746-OW8 Digital Contact Output Module Allen-Bradley","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cspan style=\"color: #d9534f;\"\u003e\u003cstrong\u003eAllen-Bradley 1746-OW8\u003c\/strong\u003e\u003c\/span\u003e is an 8-channel electromechanical relay contact output module engineered for the SLC 500 programmable controller architecture. Operating across wide AC and DC voltage spans (5–265 Vac \/ 5–125 Vdc), this module provides dry-contact switching capabilities across two isolated groups of four Normally Open (N.O.) channels. The \u003cspan style=\"color: #d9534f;\"\u003e\u003cstrong\u003e1746-OW8\u003c\/strong\u003e\u003c\/span\u003e enables direct control of interposing circuits, motor starters, solenoid valves, and warning beacons without requiring auxiliary interposing relays.\u003c\/p\u003e\n\n\u003cp\u003eCompatible with modular SLC 5\/01 through SLC 5\/05 processors and remote 1746 I\/O chassis adapters, the module draws 85 mA at 5 Vdc and 90 mA at 24 Vdc from the backplane. Its dual-group isolated common architecture allows engineers to switch distinct AC and DC supply voltages within a single single-slot chassis location, conserving enclosure footprint and simplifying panel assembly.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features and Benefits\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDual Isolated Common Groups:\u003c\/strong\u003e Features 2 isolated groups (4 channels per group) allowing multi-voltage AC and DC circuit control.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWide Operational Voltage Span:\u003c\/strong\u003e Switches field loads ranging from 5 to 265 Vac (47–63 Hz) and 5 to 125 Vdc safely.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEliminates Interposing Relays:\u003c\/strong\u003e High-capacity dry contacts drive heavy field coils directly, reducing wiring complexity and enclosure costs.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHazardous Location Certification:\u003c\/strong\u003e Certified for Class 1, Division 2 hazardous operating environments (Pollution Degree 2 compliant).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLow Backplane Power Draw:\u003c\/strong\u003e Consumes only 85 mA at 5 Vdc and 90 mA at 24 Vdc with a low maximum heat dissipation of 3.7 W.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRobust Mechanical Durability:\u003c\/strong\u003e Rated for 30g operational shock and 2g vibration resistance across a -25 °C to +60 °C temperature window.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eTechnical Specifications\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eDetailed electrical, mechanical, and operational parameters for the \u003cspan style=\"color: #d9534f;\"\u003e\u003cstrong\u003eAllen-Bradley 1746-OW8\u003c\/strong\u003e\u003c\/span\u003e are structured below:\u003c\/p\u003e\n\n\u003ctable border=\"1\" cellpadding=\"6\" cellspacing=\"0\" style=\"border-collapse: collapse; width: 100%;\"\u003e\n  \u003cthead\u003e\n    \u003ctr style=\"background-color: #f2f2f2;\"\u003e\n      \u003cth style=\"text-align: left;\"\u003e\u003cstrong\u003eCategory\u003c\/strong\u003e\u003c\/th\u003e\n      \u003cth style=\"text-align: left;\"\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n      \u003cth style=\"text-align: left;\"\u003e\u003cstrong\u003eSpecification Details\u003c\/strong\u003e\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd rowspan=\"3\"\u003e\u003cstrong\u003eCore Platform\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eManufacturer \u0026amp; Line\u003c\/td\u003e\n      \u003ctd\u003e\n\u003cstrong\u003eAllen-Bradley\u003c\/strong\u003e \/ Rockwell Automation (SLC 500 Platform)\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003ePart Number \u0026amp; GTIN\u003c\/td\u003e\n      \u003ctd\u003e\n\u003cspan style=\"color: #d9534f;\"\u003e\u003cstrong\u003e1746-OW8\u003c\/strong\u003e\u003c\/span\u003e (GTIN: 10662073578908)\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eModule Category\u003c\/td\u003e\n      \u003ctd\u003eDigital Electromechanical Contact Output Module (8 N.O. Relays)\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd rowspan=\"4\"\u003e\u003cstrong\u003eElectrical Ratings\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eOperating Voltage Range\u003c\/td\u003e\n      \u003ctd\u003e5 to 265 Vac (47–63 Hz) \/ 5 to 125 Vdc\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eContinuous Current Limit\u003c\/td\u003e\n      \u003ctd\u003e1.5 A @ 120 Vac; 1.2 A @ 24 Vdc (16.0 A max per module \/ 8.0 A per group)\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eGroup Configuration\u003c\/td\u003e\n      \u003ctd\u003e2 isolated groups with 4 channels per common terminal\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eBackplane Current \u0026amp; Heat\u003c\/td\u003e\n      \u003ctd\u003e85 mA @ 5 Vdc; 90 mA @ 24 Vdc; 3.7 W max thermal dissipation (0.138 W\/point)\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd rowspan=\"3\"\u003e\u003cstrong\u003eTiming \u0026amp; Isolation\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eSignal Switching Delay\u003c\/td\u003e\n      \u003ctd\u003eON-state delay: 10.0 ms; OFF-state delay: 10.0 ms (Resistive load)\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eStep Response Rate\u003c\/td\u003e\n      \u003ctd\u003e60 ms IN \/ 2.5 ms OUT overall loop response\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eEnvironmental Limits\u003c\/td\u003e\n      \u003ctd\u003eOperating: -25 °C to +60 °C; Non-operating: -40 °C to +85 °C; RH 5–95% non-condensing\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd rowspan=\"2\"\u003e\u003cstrong\u003eMechanics \u0026amp; Safety\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eShock, Vibration \u0026amp; Weight\u003c\/td\u003e\n      \u003ctd\u003e30g operational shock; 2g @ 10–500 Hz vibration; Weight: 1.00 lbs (0.45 kg)\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHazardous Certifications\u003c\/td\u003e\n      \u003ctd\u003eClass 1, Division 2 rating; EN\/IEC 60664-1 Pollution Degree 2 enclosure compliant\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003e\u003cstrong\u003eTarget Equipment and Application Scenarios\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect control of 120\/240 Vac motor starter contactors and heavy industrial solenoid coils.\u003c\/li\u003e\n  \u003cli\u003eMixed-voltage control panels requiring simultaneous switching of 24 Vdc pilot circuits and 120 Vac alarm horns.\u003c\/li\u003e\n  \u003cli\u003eRemote I\/O rack expansion slots running over RIO communication networks in water\/wastewater plants.\u003c\/li\u003e\n  \u003cli\u003eRetrofit modernization of legacy SLC 5\/01 through SLC 5\/05 PLC racks in chemical and material handling facilities.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eDiagnostic Capabilities and Signal Analysis\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cspan style=\"color: #d9534f;\"\u003e\u003cstrong\u003eAllen-Bradley 1746-OW8\u003c\/strong\u003e\u003c\/span\u003e provides clear hardware-level status visualization via individual front-panel LED indicators. Each LED illuminates when the internal logic energizes the corresponding contact coil. Because mechanical relays can experience contact wear under highly inductive loads, verifying LED illuminations against field-side voltage measurements assists maintenance teams in diagnosing contact pitting or welded relay states without taking the PLC chassis offline.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGlobal PLC Spare HUB's Insight \u0026amp; Field Experience\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eWhile the \u003cspan style=\"color: #d9534f;\"\u003e\u003cstrong\u003e1746-OW8\u003c\/strong\u003e\u003c\/span\u003e eliminates external interposing relays for many applications, driving highly inductive AC or DC loads (such as large solenoid valves or brake coils) subjects mechanical contacts to voltage spikes during turn-off. We strongly advise installing external surge suppressors—such as RC networks for AC circuits or flyback diodes for DC circuits—directly across field loads to extend internal relay contact lifespans.\u003c\/p\u003e\n\n\u003cp\u003eWhen wiring the two common groups, keep total group current under 8.0 A continuous. In Class 1, Division 2 hazardous locations, never pull or plug the module, terminal block, or field connections while the backplane or field circuits remain energized to prevent hazardous electrical arcing.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompliance, Shipping, and Warranty Terms\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePackage Contents:\u003c\/strong\u003e 1 x New factory-sealed \u003cspan style=\"color: #d9534f;\"\u003e\u003cstrong\u003eAllen-Bradley 1746-OW8\u003c\/strong\u003e\u003c\/span\u003e 8-channel relay output module in original factory protective box.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWarranty Coverage:\u003c\/strong\u003e Fully backed by a 12-month factory replacement warranty active from the dispatch date.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eExpress Global Courier:\u003c\/strong\u003e Fast international dispatch within 24–48 hours using express DHL, FedEx, and UPS courier networks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions (FAQ)\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eQuestion: Can I wire 120 Vac loads on Group 0 and 24 Vdc loads on Group 1 simultaneously?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eAnswer: Yes, the two 4-point output groups are electrically isolated from each other, allowing separate supply voltages across each common terminal.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQuestion: Does this relay output module require external power connections to drive the internal relay coils?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eAnswer: No, the internal relay coils derive control power directly from the SLC backplane (85 mA at 5 Vdc and 90 mA at 24 Vdc).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQuestion: What protective measure prevents premature contact failure when switching inductive solenoid valves?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eAnswer: Installing external metal oxide varistors (MOVs) or RC suppression networks across AC field loads suppresses voltage transients during contact break.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQuestion: Is this relay unit compatible with SLC 500 remote expansion racks?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eAnswer: Yes, it installs into any available slot of a remote 1746 chassis, provided Slot 0 contains a 1746 communication adapter.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQuestion: What safety precaution must be observed when working on this unit in hazardous environments?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eAnswer: Power down both backplane supply and field circuit power prior to disconnecting terminal blocks or replacing the hardware to prevent electrical arc ignition risks.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":45013911961782,"sku":"1746-OW8","price":127.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0722\/7863\/8774\/files\/1746-OW8_94f67f74-108e-44c1-88e3-ef59495fba15.jpg?v=1785138553","url":"https:\/\/www.plcsparehub.com\/products\/1746-ow8-digital-contact-output-module-allen-bradley","provider":"Global PLC Spare Hub","version":"1.0","type":"link"}