TU846 3BSE022460R1 | ABB Redundant Module Termination Unit

Overview

The ABB TU846 (Part Number: 3BSE022460R1) is a Redundant Module Termination Unit (MTU) designed for the S800 I/O automation platform. It acts as a passive, high-reliability electrical baseplate engineered to host redundant Optical ModuleBus Modems (such as TB840 or TB840A), routing system logic power and dual-line communication paths across parallel hardware layers without any active electronic points of failure on the board itself.

Technical Specifications

• Product Type: Module Termination Unit (MTU) for Redundant Configuration
• Model Code: TU846
• Part Number: 3BSE022460R1
• Manufacturer: ABB
• System Compatibility: S800 I/O Family (Connects dual TB840/TB840A Modems to Redundant I/O clusters)
• Communication Protocol Support: ABB's ModuleBus
• Redundancy Support: Yes (Module Redundancy and Line Redundancy capability)
• Nominal Supply Voltage: 24 V DC (Acceptable range: 19.2 to 30.0 V DC)
• Maximum ModuleBus Power Current: 5 V @ 1.5 A, 24 V @ 1.5 A distribution
• Rated Insulation / Dielectric Test Voltage: 50 V / 500 V AC
• Acceptable Wire Sizes: Solid/Stranded 0.2 to 2.5 mm² (24 to 12 AWG)
• Ingress Protection Rating: IP20 (IEC 60529 Compliant)
• Physical Dimensions: 18.6 cm x 12.4 cm x 4.7 cm
• Product Net Weight: 0.45 kg

Installation Notes

• Snap the TU846 MTU firmly onto the standard horizontal cabinet DIN rail until the structural grounding springs lock tightly against the metal frame.
• Set the localized rotary cluster address switch to the exact node designation assigned within the master controller software configuration.
• Adjust the mechanical alignment keys using a flat tool to mirror the profile of the target S800 redundant modems prior to module insertion.
• Terminate field power lines and communication cables into the compression screw blocks, ensuring proper wire strip lengths to maintain IP20 electrical safety boundaries.