ABB TU842 3BSE020850R1 S800 I/O Redundant Termination Unit

Product Overview

The ABB TU842 (3BSE020850R1) serves as a high-availability redundant Module Termination Unit (MTU) within the S800 I/O family. It provides the essential physical and electrical interface for up to 16 channels, supporting critical modules like the AI843, AO845, DI840, and DO880. This unit enables dual-module redundancy, ensuring continuous process operation even during a single module failure. We supply this component as 100% brand new original equipment, factory-sealed to maintain peak industrial performance.

Technical Specifications

The TU842 features a robust 56-point process connection array, engineered for high-current applications and redundant signal paths.

Engineering Advantages

• Mission-Critical Redundancy: The TU842 supports two I/O modules simultaneously. If one module fails, the secondary module takes over the load instantly, eliminating process downtime in power plants or chemical refineries.

• High-Current Handling: Unlike standard termination units, the TU842 manages up to 10 A through process connections. This solves the challenge of powering power-hungry field actuators and sensors directly through the MTU.

• Streamlined Wiring Architecture: The 56-point terminal block eliminates the need for external distribution strips. It integrates 20 dedicated 0V process power terminals, simplifying the grounding of complex 16-channel loops in crowded cabinets.

• Optimized Vibration Resistance: Secure screw-terminal blocks and horizontal DIN-rail mounting ensure signal stability. This mechanical design prevents wire fatigue and intermittent contact in high-vibration industrial environments.

FAQs

• Which I/O modules are compatible with the TU842?

  The TU842 specifically supports ABB S800 modules including AI843, AO845/AO845A, DI840, DI880, DO840, DO880, and DP840. Using non-compatible modules may result in bus communication errors.

• Does this unit arrive with the I/O modules included?

  No. The TU842 is the termination baseplate only. You must purchase the electronic I/O modules separately. We guarantee this baseplate is 100% brand new and ready for installation.

• What are the torque requirements for field wiring?

  To ensure a gas-tight connection and prevent terminal damage, apply a torque of 0.5 - 0.6 Nm. Strip wires to exactly 7 mm to maximize contact area within the terminal cage.

• Can I mount the TU842 vertically?

  ABB recommends horizontal mounting for this specific model to ensure proper thermal management at the rated 55 °C ambient temperature. Vertical mounting may require derating of the maximum current capacity.