The ABB TU842 (3BSE020850R1) is a redundant, horizontal Module Termination Unit (MTU) designed for the S800 I/O system. It provides a robust interface for connecting field signals to I/O modules while facilitating the distribution of the ModuleBus and process power.

Features

• Supports up to 16 I/O channels with 3-wire connection capability.
• Redundant configuration support for high-availability applications.
• Integrated process power distribution (2+2 connections).
• Mechanical keying system prevents the insertion of incorrect I/O modules.
• Latching mechanism for secure DIN rail mounting and integrated grounding.
• Distributes ModuleBus signals to I/O modules and subsequent MTUs.

Applications

• Oil and Gas: Onshore processing plants and offshore drilling platforms.
• Marine Engineering: Engine room automation and dynamic positioning systems.
• Metallurgy and Mining: Blast furnace automation and converter control.
• Water Treatment: Sewage treatment plants and remote pumping stations.

Technical Specifications

Installation Guidelines

• Ensure the DIN rail is properly grounded to provide a common reference for the MTU latching system.
• Verify that mechanical keys are correctly set for the specific I/O module type to prevent improper installation.
• Power down the system before inserting or removing any I/O modules from the MTU.
• Maintain adequate spacing for ventilation to ensure operating temperatures remain within the 0 to +55 degC range.
• Route field wiring away from high-EMI sources to maintain signal integrity.

FAQ

What is the TU842 (3BSE020850R1)?

It is a redundant, horizontal Module Termination Unit (MTU) designed for the ABB S800 I/O system, used for connecting field signals to I/O modules and distributing the ModuleBus.

How many I/O channels does it support?

The unit supports up to 16 I/O channels, with each channel featuring two I/O connections and one ZP connection.

How is the MTU configured for specific I/O modules?

The MTU uses four mechanical keys (two for each I/O module) with six positions each, allowing for 36 different mechanical configurations to prevent incorrect module insertion.