{"product_id":"abb-tu891-industrial-automation-module-mtu-for-is-i-o","title":"ABB TU891 Industrial Automation Module – MTU for IS I\/O","description":"\u003ch2\u003eProduct Overview\u003c\/h2\u003e\u003cp\u003eThe ABB TU891 is a compact Module Termination Unit (MTU) engineered for intrinsic safety (I.S.) applications. It provides 27 gray terminals for field signals and process voltage connections, ensuring reliable and organized wiring. With a maximum rated voltage of 50 V and a maximum current of 2 A per channel, the TU891 is designed to work seamlessly with ABB I\/O modules such as AI890, AI893, AI895, AO890, AO895, DI890, and DO890. This MTU distributes the ModuleBus to the connected I\/O module and to the next MTU, while also generating the correct address by shifting outgoing position signals. Its mechanical keying prevents insertion of incompatible modules, safeguarding your system integrity.\u003c\/p\u003e\u003cp\u003eThe TU891 features a latching device for secure DIN rail mounting and supports horizontal orientation. It is a single I\/O unit, ideal for compact installations. The unit's design ensures that field signals and process power are connected efficiently, reducing wiring complexity and installation time.\u003c\/p\u003e\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\u003cp\u003eBelow are the key technical specifications for the ABB TU891, sourced directly from the manufacturer's data:\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eArticle Number\u003c\/td\u003e\n\u003ctd\u003e3BSC840157R1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eCompact\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnection\u003c\/td\u003e\n\u003ctd\u003eTerminal block\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChannels\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage\u003c\/td\u003e\n\u003ctd\u003e24 V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eHorizontal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Detail\u003c\/td\u003e\n\u003ctd\u003e55 °C (131 °F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUse with I\/O\u003c\/td\u003e\n\u003ctd\u003eAI890, AI893, AI895, AO890, AO895, DI890, DO890\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProcess Connections\u003c\/td\u003e\n\u003ctd\u003e27 gray terminals\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSingle\/Redundant I\/O\u003c\/td\u003e\n\u003ctd\u003eSingle\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Current per I\/O Channel\u003c\/td\u003e\n\u003ctd\u003e2 A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAcceptable Wire Sizes (Process Connector)\u003c\/td\u003e\n\u003ctd\u003eSolid: 0.2–4 mm²; Stranded: 0.2–2.5 mm², 24–12 AWG\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecommended Torque\u003c\/td\u003e\n\u003ctd\u003e0.5–0.6 Nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Supply Connector Wire Sizes\u003c\/td\u003e\n\u003ctd\u003e0.25–2.5 mm², 24–14 AWG\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDielectric Test Voltage\u003c\/td\u003e\n\u003ctd\u003e500 V a.c.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCE Mark\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eElectrical Safety\u003c\/td\u003e\n\u003ctd\u003eIEC 61131-EN 61010-1, EN 61010-2-201\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMarine Certification\u003c\/td\u003e\n\u003ctd\u003eABS, BV, DNV-GL, LR\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e0 to +55 °C (+32 to +131 °F); Storage: -40 to +70 °C (-40 to +158 °F), RH=5 to 95% non-condensing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePollution Degree\u003c\/td\u003e\n\u003ctd\u003eDegree 2, IEC 60664-1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrosion Protection\u003c\/td\u003e\n\u003ctd\u003eISA-S71.04: G3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax Ambient Temperature\u003c\/td\u003e\n\u003ctd\u003e55 °C (131 °F) horizontal; 40 °C (104 °F) vertical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProtection Class\u003c\/td\u003e\n\u003ctd\u003eIP20 according to IEC 60529\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMechanical Operating Conditions\u003c\/td\u003e\n\u003ctd\u003eIEC\/EN 61131-2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEMC\u003c\/td\u003e\n\u003ctd\u003eEN 61000-6-4, EN 61000-6-2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOvervoltage Categories\u003c\/td\u003e\n\u003ctd\u003eIEC\/EN 60664-1, EN 50178\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEquipment Class\u003c\/td\u003e\n\u003ctd\u003eClass I according to IEC 61140 (earth protected)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRoHS Compliance\u003c\/td\u003e\n\u003ctd\u003eEN 50581:2012\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWEEE Compliance\u003c\/td\u003e\n\u003ctd\u003eDIRECTIVE\/2012\/19\/EU\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWidth\u003c\/td\u003e\n\u003ctd\u003e64 mm (1.77 in.) including connector; 58.5 mm (2.3 in.) edge-to-edge installed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDepth\u003c\/td\u003e\n\u003ctd\u003e58 mm (2.28 in.); 106 mm (4.2 in.) including terminals\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHeight\u003c\/td\u003e\n\u003ctd\u003e194 mm (7.6 in.) including latch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.17 kg (0.37 lbs)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch2\u003eIndustry Applications\u003c\/h2\u003e\u003cp\u003eThe ABB TU891 is purpose-built for intrinsic safety applications, making it an essential component in hazardous industrial environments where safety is paramount. It is commonly used in:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eProcess Control Systems:\u003c\/strong\u003e In chemical plants and refineries, the TU891 ensures safe signal transmission to I\/O modules like AI890 and AO890, maintaining process integrity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMarine and Offshore Installations:\u003c\/strong\u003e With marine certifications (ABS, BV, DNV-GL, LR), the TU891 is suitable for shipboard automation, where reliability under harsh conditions is critical.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompact Control Panels:\u003c\/strong\u003e Its compact design and DIN rail mounting make it ideal for space-constrained panels, allowing efficient use of cabinet space while delivering robust performance.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eBy using the TU891, you can achieve safe and reliable operation in demanding settings, reducing downtime and maintenance costs.\u003c\/p\u003e\u003ch2\u003eInstallation \u0026amp; Setup Guidance\u003c\/h2\u003e\u003cp\u003eProper installation is crucial for optimal performance of the ABB TU891. Follow these steps:\u003c\/p\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting:\u003c\/strong\u003e Attach the TU891 onto a standard DIN rail using the latching device. Ensure the rail is clean and level to guarantee a secure fit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrientation:\u003c\/strong\u003e The unit is designed for horizontal mounting. If vertical mounting is necessary, note that the maximum ambient temperature drops to 40 °C (104 °F) to maintain thermal performance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWiring:\u003c\/strong\u003e Use the gray terminals for field signals and process voltage. For the process connector, accept solid wires from 0.2 to 4 mm² and stranded wires from 0.2 to 2.5 mm² (24–12 AWG). For the power supply connector, use wires from 0.25 to 2.5 mm² (24–14 AWG). Tighten terminals to a torque of 0.5–0.6 Nm to ensure reliable connections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical Keying:\u003c\/strong\u003e The TU891 features mechanical keys that are opposite in gender to other MTUs, ensuring it mates only with IS I\/O modules. Do not attempt to force connection with incompatible modules.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAddress Configuration:\u003c\/strong\u003e The MTU automatically generates the correct address for the I\/O module by shifting outgoing position signals. No manual addressing is required, simplifying setup.\u003c\/li\u003e\n\u003c\/ol\u003e\u003cp\u003eAlways follow the manufacturer's instructions and applicable safety standards during installation.\u003c\/p\u003e\u003ch2\u003eMaintenance \u0026amp; Reliability\u003c\/h2\u003e\u003cp\u003eRegular maintenance ensures long-term reliability of the TU891. Although the unit has no moving parts, periodic checks are recommended:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eInspect Connections:\u003c\/strong\u003e Periodically verify that all terminal screws remain tight (0.5–0.6 Nm) to prevent loose connections that can cause signal errors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCleanliness:\u003c\/strong\u003e Keep the unit free from dust and debris. The IP20 protection rating means it is suitable for indoor use but should be protected from excessive moisture and contaminants.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnvironmental Monitoring:\u003c\/strong\u003e Ensure the operating temperature stays within 0 to +55 °C and humidity between 5% and 95% non-condensing. High humidity can lead to condensation and corrosion.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorrosion Protection:\u003c\/strong\u003e The unit is rated ISA-S71.04 G3, offering moderate corrosion resistance. In corrosive environments, consider additional enclosure protection.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eBy following these simple steps, you can extend the service life of the TU891 and minimize unexpected downtime.\u003c\/p\u003e\u003ch2\u003eCompatibility \u0026amp; Integration\u003c\/h2\u003e\u003cp\u003eThe ABB TU891 is designed to work exclusively with ABB I.S. I\/O modules, including AI890, AI893, AI895, AO890, AO895, DI890, and DO890. It provides the ModuleBus interface and mechanical keying that ensures only compatible modules are installed. The TU891 supports single I\/O configurations and is not intended for redundant setups. It integrates seamlessly into ABB's 800xA or similar control systems, providing a reliable interface between field signals and the controller.\u003c\/p\u003e\u003cp\u003eFor any integration questions, refer to the ABB system documentation or consult with a qualified engineer.\u003c\/p\u003e\u003ch2\u003eSelection Guide \u0026amp; Purchasing Advice\u003c\/h2\u003e\u003cp\u003eWhen selecting the TU891 for your application, consider the following:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVerify Compatibility:\u003c\/strong\u003e Ensure your I\/O modules are from the listed series (AI890, AI893, AI895, AO890, AO895, DI890, DO890) and are intrinsic safety certified.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheck Environmental Conditions:\u003c\/strong\u003e Confirm that your installation environment meets the operating temperature and humidity ranges specified.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlan for Mounting:\u003c\/strong\u003e Decide on horizontal vs. vertical mounting, as this affects the maximum ambient temperature rating.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrder the Correct Article Number:\u003c\/strong\u003e The article number for the TU891 is 3BSC840157R1. Always verify this when ordering to avoid compatibility issues.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003ePLC Source PRO is a reliable supplier for genuine ABB TU891 modules and other industrial automation spares. We ensure fast delivery and competitive pricing to keep your operations running smoothly.\u003c\/p\u003e","brand":"ABB","offers":[{"title":"Default","offer_id":44447364874339,"sku":"TU891","price":232.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0678\/8635\/0435\/files\/07-KT-97_20ABB__E5_89_AF_E6_9C_AC-c1_730cd012-d39a-41f7-900d-bd1564e3efab.jpg?v=1785965072","url":"https:\/\/www.plcsourcepro.com\/he\/products\/abb-tu891-industrial-automation-module-mtu-for-is-i-o","provider":"PLC Source PRO","version":"1.0","type":"link"}