{"product_id":"abb-tu891-compact-terminal-unit","title":"ABB TU891 Compact Terminal Unit","description":"\u003cp\u003eThe \u003cstrong\u003eABB TU891\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003eTU891\u003c\/strong\u003e Compact Terminal Unit, operates as a dedicated hardware component for single I\/O module termination and signal distribution within ABB S800 I\/O platforms. Configured for single I\/O configurations with AI890, AI893, AI895, AO890, AO895, DI890, and DO890 modules, the base provides direct physical\/electrical execution. It routes field wiring through 27 gray process terminals, ensuring secure point-to-point connections to active I\/O cards without introducing signal latency or line noise.\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\u003eTU891\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eABB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eSweden\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\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e64 x 58 x 194 mm (W x D x H, including connector and latch)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e55 deg C (131 deg F) max operating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003ePassive Power Distribution\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Modules\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 Terminals\u003c\/td\u003e\n\u003ctd\u003e27 Gray Terminals\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax Current per Channel\u003c\/td\u003e\n\u003ctd\u003e2 A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProcess Wire Gauge\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\u003eWire Torque\u003c\/td\u003e\n\u003ctd\u003e0.5 - 0.6 Nm (Process and Power Supply Terminals)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDielectric Test Voltage\u003c\/td\u003e\n\u003ctd\u003e500 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConfiguration Type\u003c\/td\u003e\n\u003ctd\u003eSingle I\/O (Horizontal Mounting)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eDeterministic Backplane \u0026amp; I\/O Density Scaling Execution\u003c\/h3\u003e\n\u003cp\u003eThe compact terminal unit incorporates ABB proprietary backplane bus communication velocity Licences and deterministic networking protocols to ensure synchronized data exchange across distributed controller nodes. Operating as a single-channel module base, the hardware manages local field signal frames while supporting high-density I\/O configurations. Strict firmware flash compatibility across attached S800 I\/O cards maintains low backplane latencies, stable power supply distribution, and high noise immunity with a 500 VAC dielectric test rating.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: What are the recommended terminal tightening torques for process and power connections on the TU891?\u003c\/p\u003e\n\u003cp\u003eA: The recommended torque for both the 27 process terminals and the power supply connector is 0.5 to 0.6 Nm.\u003c\/p\u003e\n\u003cp\u003eQ: Can the TU891 terminal unit be used in redundant I\/O module configurations?\u003c\/p\u003e\n\u003cp\u003eA: No. The TU891 is specifically designed for single I\/O module architectures. Redundant configurations require dual-channel termination units.\u003c\/p\u003e\n\u003cp\u003eQ: What wire sizes are supported by the process terminals on the TU891?\u003c\/p\u003e\n\u003cp\u003eA: The process terminals accept solid wire from 0.2 to 4 mm² and stranded wire from 0.2 to 2.5 mm² (24 to 12 AWG).\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Isolation \u0026amp; Torque Verification\u003c\/strong\u003e: De-energize all 24 VDC power and field loop circuits before attaching wires. Tighten all screw terminals using a calibrated torque screwdriver set strictly to 0.5 - 0.6 Nm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDIN-Rail Horizontal Mounting\u003c\/strong\u003e: Mount the unit horizontally on standard 35 mm DIN rails. Ensure top and bottom mounting latches fully snap into position to secure mechanical lock and earth grounding contact.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConductor Preparation\u003c\/strong\u003e: Strip process conductors to 7 - 8 mm. Insert solid (0.2 - 4 mm²) or stranded (0.2 - 2.5 mm²) conductors completely into the designated gray process terminals to guarantee 500 VAC dielectric isolation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrounding \u0026amp; Cable Shielding\u003c\/strong\u003e: Clamp field cable shields to designated chassis ground bars. Ensure ground braids maintain low impedance with at least 5 full thread engagements on M4\/M5 cabinet grounding studs.\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"ABB","offers":[{"title":"Default Title","offer_id":45373359161459,"sku":"TU891","price":233.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0644\/4348\/2227\/files\/TU891_92b95f76-56b4-4f1f-bbff-bec430f50154.png?v=1787108277","url":"https:\/\/www.dcssupplier.com\/ar\/products\/abb-tu891-compact-terminal-unit","provider":"DcsSupplier Limited","version":"1.0","type":"link"}