TU847 3BSE022462R1 | ABB S800 I/O Redundant PROFIBUS Module Termination Unit

Product Overview

The ABB TU847 (3BSE022462R1) functions as the primary communication and power distribution base for redundant S800 I/O configurations on PROFIBUS DP-V1 networks. This Module Termination Unit (MTU) houses dual CI840 or CI840A Fieldbus Communication Interfaces, establishing a fail-safe link between the distributed I/O cluster and the master controller. It routes incoming PROFIBUS signals and 24 V d.c. power to the attached modems while distributing the ModuleBus signals to the rest of the I/O station. We supply this unit as 100% Brand New and Original to ensure maximum bus integrity and system longevity.

Technical Specifications

The TU847 provides a robust electrical framework with the following technical parameters:

Engineering Advantages

• Mission-Critical Redundancy: The TU847 supports two CI840 communication modules simultaneously. This dual-slot architecture creates a redundant communication path, ensuring that a single modem failure or fieldbus segment fault does not disconnect the entire I/O cluster from the DCS.

• Integrated Service Accessibility: Dedicated RJ45 service ports allow engineers to perform local diagnostics and configuration without disturbing the main PROFIBUS wiring. This feature streamlines commissioning and site maintenance activities.

• High-Capacity Power Distribution: The MTU distributes up to 1.5 A at both 5 V and 24 V to the subsequent I/O modules on the ModuleBus. This robust power delivery supports high-density clusters, reducing the need for additional power injection points along the DIN rail.

• Error-Proof Hardware Keying: The unit utilizes a mechanical keying system with 36 different combinations. This physical lockout prevents technicians from accidentally inserting incorrect module types into the MTU slots, protecting the hardware from potential electrical mismatch damage.

• Versatile Field Connectivity: The DSUB9 connector ensures a standard, low-impedance connection to the PROFIBUS network. For power and grounding, the terminal blocks accept wire gauges up to 14 AWG, providing secure, vibration-resistant terminations for industrial environments.

FAQs

• Does the TU847 support Hot Swap for the MTU base? No. While the CI840 modules themselves allow for replacement under power when configured correctly, the TU847 base unit forms part of the permanent station infrastructure. You must de-energize the cluster before removing the MTU from the DIN rail.

• Can I use the TU847 with only one CI840 module? Yes. The TU847 functions with a single CI840 or CI840A module. However, the system operates without communication redundancy until you install the second modem in the adjacent slot.

• What is the significance of the 500 V a.c. dielectric test voltage? This rating confirms the module's ability to withstand transient voltage surges between the process power and the logic circuits. This protects the internal ModuleBus and the PROFIBUS network from electrical noise often found in industrial motor control centers.

• What torque should I apply to the power terminals? Apply a torque between 0.5 and 0.6 Nm (approx. 4.4 to 5.3 lb-in). Maintaining this specific pressure prevents loose connections due to thermal cycling and ensures the stripping length of 6-7.5 mm remains securely clamped.