TU845 ABB 3BSE021447R1 Vertical Mount Termination Unit

Product Overview

The ABB TU845 (3BSE021447R1) serves as a robust Module Termination Unit (MTU) designed for the S800 I/O system. This 100% brand new and original component provides the essential interface between field wiring and I/O modules, specifically supporting redundant configurations for AI845 modules. It accommodates up to 8 I/O channels and facilitates seamless signal distribution across the ModuleBus. By integrating electrical connections and address logic into a single vertical-mount unit, the TU845 ensures high-density signal management for System 800xA and other ABB controller platforms.

Technical Specifications

Engineering Advantages

• Redundancy Support: The TU845 specifically accommodates redundant AI845 modules. This dual-slot capability ensures that the process remains online even if one I/O module fails, providing the high availability required for mission-critical industrial loops.

• Automatic Addressing Logic: The MTU eliminates manual configuration errors by generating the correct address for each I/O module. It shifts the outgoing position signals to the next MTU in the cluster, simplifying system expansion and reducing commissioning time.

• Signal Versatility with TY801: This unit utilizes individual TY801 shunt sticks for signal conditioning. By inserting the shunt stick, engineers can switch a channel between voltage and current input modes without replacing the entire termination base or adding external converters.

• Optimized Cable Management: With 40 process connection points and dedicated process power distribution (2+2 connections), the TU845 organizes complex field wiring into a compact footprint. The vertical mounting design saves significant horizontal rail space in crowded control cabinets.

• Secure Mechanical Stability: A robust mechanical latch locks the MTU securely to the DIN rail. This feature prevents accidental disconnection in high-vibration environments, such as marine engine rooms or heavy manufacturing floors.

FAQs

• Can the TU845 be used with non-redundant modules?

  Yes. While the TU845 supports redundant AI845 modules, it also functions perfectly with single modules such as the AI880 or AI880A. The secondary slot simply remains empty or available for future expansion.

• How does the TY801 shunt stick affect the input signal?

  The TY801 shunt stick provides the necessary resistance to convert a 4-20 mA current signal into a voltage signal readable by the I/O module. Without the shunt stick, the channel operates as a high-impedance voltage input.

• Is vertical mounting mandatory for this specific MTU?

  ABB designs the TU845 specifically for vertical mounting to optimize heat dissipation for the AI845 series. Installing it horizontally may impede airflow and reduce the maximum operating temperature rating.

• Does the unit come with the I/O modules included?

  No. The 3BSE021447R1 is the Module Termination Unit (the base). You must purchase the AI845 or AI880 I/O modules separately to complete the assembly.