TU851 ABB 3BSE068782R1 Extended Module Termination Unit

Product Overview

The ABB TU851 (3BSE068782R1) serves as a robust Extended Module Termination Unit (MTU) designed for high-density signal management within the S800 I/O system. This unit acts as the primary physical and electrical interface for up to 16 isolated field channels, supporting high-voltage applications up to 250V and 3A per channel. The TU851 provides the critical communication pathway for the ModuleBus, distributing signals to the active I/O module and daisy-chaining connectivity to subsequent MTUs in the rack. By integrating mechanical keying and a dedicated latching device for DIN rail grounding, the TU851 ensures industrial-grade stability and prevents wiring errors during deployment. We supply this module as 100% brand new and original, ensuring peak performance for AC 800M controller environments.

Technical Specifications

Engineering Advantages

The TU851 3BSE068782R1 resolves complex signal routing and safety requirements in process automation:

• High-Voltage Signal Isolation: The unit manages up to 250V field signals across 16 isolated channels. This prevents ground loops and electrical interference from migrating between field devices and the sensitive ModuleBus logic.

• Intelligent Address Generation: The MTU automatically generates the correct hardware address for the inserted I/O module by shifting outgoing position signals to the next MTU in the sequence. This eliminates manual dip-switch addressing and reduces commissioning time.

• Mechanical Safety Keying: Two six-position mechanical keys allow engineers to "lock" the MTU configuration for specific module types. This physical barrier prevents maintenance personnel from accidentally inserting the wrong I/O module, protecting the hardware from electrical damage.

• Secure DIN Rail Grounding: An integrated mechanical latching device secures the MTU to the DIN rail while simultaneously establishing the mandatory ground path. This simplifies EMC compliance and ensures the chassis ground remains intact during cabinet vibration.

• Flexible Mounting Direction: The design supports both horizontal and vertical mounting. This flexibility allows engineers to optimize cabinet space and airflow, particularly in high-current applications where thermal management is critical.

FAQs

• Does the TU851 come with the keys already configured?

  The MTU includes two adjustable mechanical keys. You set these keys based on the specific I/O module type (e.g., DI820 or DO820) you intend to use. This setup provides 36 unique configuration possibilities to prevent module mismatch.

• Is this a brand new 3BSE068782R1 unit?

  Yes. We only supply 100% brand new and original ABB hardware in factory-sealed packaging. This unit originates from ABB Sweden and carries the full manufacturer warranty.

• Can I use the TU851 for redundant I/O configurations?

  No. The TU851 is designed for single I/O configurations. If your process requires redundancy, please consult our catalog for the appropriate redundant-capable termination units.

• What is the current rating for the field terminals?

  The TU851 supports a maximum current of 3A per channel, making it ideal for high-power digital inputs and outputs within the S800 I/O family.