{"product_id":"do821-abb-s800-i-o-relay-output-module-do821-buy-online","title":"DO821 ABB S800 I\/O Relay Output Module DO821 | Buy Online","description":"\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003e\u003cspan style=\"color: #d9534f;\"\u003eABB\u003c\/span\u003e \u003cspan style=\"color: #0275d8;\"\u003eDO821\u003c\/span\u003e\u003c\/strong\u003e (Article Number: 3BSE013250R1) is an 8-channel relay normal closed (NC) digital output module designed for the \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eS800 I\/O\u003c\/span\u003e\u003c\/strong\u003e process automation platform. Operating across 5 to 250 V a.c.\/d.c. field voltages with a continuous current rating of 3 A per channel, each output features complete channel-to-channel optical isolation. The \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eDO821\u003c\/span\u003e\u003c\/strong\u003e integrates Output Set Predetermined (OSP) fail-safe handling, ModuleBus relay power supervision, individual channel LED indicators, and robust EMC suppression components for high-reliability switching in DCS environments.\u003c\/p\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eTechnical Specifications (MECE Framework)\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003e1. Basic System Identification\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e \u003cstrong\u003e\u003cspan style=\"color: #d9534f;\"\u003eABB\u003c\/span\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel \/ Order Code:\u003c\/strong\u003e \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eDO821\u003c\/span\u003e\u003c\/strong\u003e \/ 3BSE013250R1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Series:\u003c\/strong\u003e \u003ca href=\"https:\/\/www.plcsparehub.com\/collections\/s800-i-o\"\u003e\u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eS800 I\/O\u003c\/span\u003e\u003c\/strong\u003e\u003c\/a\u003e System\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModule Type:\u003c\/strong\u003e Normally Closed (NC) Relay Digital Output Module\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical Keying Code:\u003c\/strong\u003e CA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003e2. Channel Electrical \u0026amp; Signal Characteristics\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\" style=\"border-collapse: collapse; width: 100%;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f2f2f2;\"\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eTechnical Specification Standard\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNumber of Channels\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e8 individually isolated channels (Normally Closed - NC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOperational Field Voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e230 V a.c.\/d.c. nominal (5 to 250 V a.c.\/d.c. operating range)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMax Continuous Channel Current\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e3 A continuous load current per output point\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eIsolation Architecture\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eIndividual channel-to-channel and channel-to-common optical isolation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eRated Insulation \/ Dielectric Test\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e250 V rated insulation voltage; 2000 V a.c. dielectric test voltage\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePower Dissipation\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e2.9 W typical module power dissipation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModuleBus Power Draw (5V)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e60 mA maximum current consumption at +5 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModuleBus Power Draw (24V)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e140 mA maximum current consumption at +24 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaximum Field Cable Length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e600 meters (656 yards) unshielded\/shielded cabling\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSafety Action on Fault (OSP)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eOutputs set to predetermined state upon communication error detection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003e3. Environment, Standards \u0026amp; Base Compatibility\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating Temperature:\u003c\/strong\u003e 0 to +55 °C (+32 to +131 °F) horizontal; capped at +40 °C (+104 °F) for vertical compact mounting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConformal Coating \/ Environment:\u003c\/strong\u003e Corrosion protection ISA-S71.04: G3 compliant; Pollution Degree 2; IP20 protection.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMarine Certifications:\u003c\/strong\u003e Approved by ABS, Bureau Veritas (BV), Det Norske Veritas (DNV), and Lloyd's Register (LR).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eElectrical Safety Compliance:\u003c\/strong\u003e EN 61010-1, UL 61010-1, EN 61010-2-201, and UL 61010-2-201.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Module Termination Units (MTUs):\u003c\/strong\u003e TU811, TU811V1, TU813, TU831, TU836, TU837, and TU851.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003e4. Physical Dimensions \u0026amp; Weight\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 45 mm Width x 119 mm Height x 102 mm Depth (111 mm depth including rear connector).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Net Weight:\u003c\/strong\u003e 0.23 kg (0.5 lbs).\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eSystem Diagnostics \u0026amp; Hardware Self-Monitoring\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eDO821\u003c\/span\u003e\u003c\/strong\u003e module contains comprehensive diagnostic hardware for continuous operational oversight. The front panel features 12 status LEDs: Fault (F), Run (R), Warning (W), Output Set Predetermined (O), and status lights for Channels 1 through 8. An internal converter monitor checks the 24V supply derived from the ModuleBus. If internal supply levels drop, a hardware error flag is sent via ModuleBus, triggering the Warning LED and logging module error tables inside the System 800xA or AC800M controller.\u003c\/p\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eTarget Machinery \u0026amp; Application Scenarios\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFail-safe shutdown circuits requiring Normally Closed (NC) contact logic to drop out power on signal loss.\u003c\/li\u003e\n\u003cli\u003eInterfacing high-voltage 230 VAC interlocks and motor starter coil control circuits.\u003c\/li\u003e\n\u003cli\u003eEmergency alarm annunciation, relay isolation barriers, and power distribution switching.\u003c\/li\u003e\n\u003cli\u003eHarsh chemical or offshore environments requiring ISA-S71.04 G3 corrosion resistance and marine approvals.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eInstallation \u0026amp; Wiring Guidelines\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSnap the \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eDO821\u003c\/span\u003e\u003c\/strong\u003e onto a compatible MTU base (e.g., TU811V1) with ModuleBus power removed. Align mechanical keying wheel CA to match the MTU socket setting. Ensure maximum continuous current per channel does not exceed 3 A, and select appropriate external fusing at the MTU terminals if field line short-circuit protection is required. Maintain clearance above and below the module base to facilitate convective air circulation when switching inductive 230 VAC loads.\u003c\/p\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003ePackaging, Logistics \u0026amp; Warranty Terms\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Scope:\u003c\/strong\u003e 1x Factory Sealed \u003cstrong\u003e\u003cspan style=\"color: #d9534f;\"\u003eABB\u003c\/span\u003e \u003cspan style=\"color: #0275d8;\"\u003eDO821\u003c\/span\u003e\u003c\/strong\u003e S800 Output Module (3BSE013250R1), Installation Manual.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty Terms:\u003c\/strong\u003e Full 12-month comprehensive warranty against mechanical and electronic defects.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDispatch Processing:\u003c\/strong\u003e Rapid warehouse handling with 24 to 48 hour shipping execution.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGlobal Carriers:\u003c\/strong\u003e Expedited global door-to-door transit via FedEx, UPS, or DHL.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eGlobal PLC Spare HUB's Insight \u0026amp; Field Experience\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eDuring a control retrofitting project on a marine vessel, our engineers investigated a false trip warning flagged on an \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eDO821\u003c\/span\u003e\u003c\/strong\u003e module. Diagnostic telemetry indicated intermittent 24V supply error messages over the ModuleBus, even though output loads operated normally. Investigation revealed high electrical ripple on the primary power bus caused by an aging power supply unit. Replacing the ModuleBus power line filtering stabilized voltage levels and cleared the internal supervision warning instantly. \u003cem\u003eField Tip: When utilizing NC relay outputs for critical fail-safe circuits, verify that external suppressors (RC snubbers) are fitted across AC contactor coils to eliminate inductive arc feedback into the relay contacts.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eSelection \u0026amp; Buyer's Guide\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eBefore purchasing the \u003cstrong\u003e\u003cspan style=\"color: #0275d8;\"\u003eDO821\u003c\/span\u003e\u003c\/strong\u003e, ensure your system logic explicitly requires Normally Closed (NC) contact states rather than Normally Open (NO) outputs (such as DO820). Confirm that your mounting orientation allows sufficient thermal headroom: while horizontal installation supports up to 55 °C ambient environments, vertical mounting inside compact MTUs limits the maximum ambient rating to 40 °C to preserve internal relay contact life.\u003c\/p\u003e\n\u003ch3 style=\"color: #003366;\"\u003e\u003cstrong\u003eFrequently Asked Questions (FAQ)\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ1: What contact behavior should be expected from the \u003cspan style=\"color: #0275d8;\"\u003eDO821\u003c\/span\u003e outputs when system power is completely removed?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Because channels are Normally Closed (NC), contacts remain physically closed in an unpowered state, making it ideal for fail-safe de-energize-to-trip loops.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ2: Can the internal ModuleBus relay supply supervision feature be disabled during commissioning?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Yes, software parameter settings within the controller engineering tool allow engineers to enable or disable 24\/12 V relay power monitoring flags as needed.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ3: How does the Output Set Predetermined (OSP) function protect processes during bus loss?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: If ModuleBus communication fails, the module automatically forces the 8 output channels into user-preconfigured fail-safe contact states.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ4: Is external field power required to drive the internal relay coils of the module?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: No external auxiliary power supply is required; internal relay driving voltage is derived directly from the +24 V ModuleBus distribution lines.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ5: What mechanical precautions prevent installing this module into an incorrect MTU socket?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: The module uses mechanical keying code CA, which must match the adjustable keying dial on the MTU base to allow proper physical mating.\u003c\/p\u003e","brand":"ABB","offers":[{"title":"Default Title","offer_id":45446621888694,"sku":null,"price":0.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0722\/7863\/8774\/files\/DO821-3.jpg?v=1789379601","url":"https:\/\/www.plcsparehub.com\/products\/do821-abb-s800-i-o-relay-output-module-do821-buy-online","provider":"Global PLC Spare Hub","version":"1.0","type":"link"}