ABB TU833 3BSE038726R1 Extended Module Termination Unit

The ABB 3BSE038726R1, also cataloged as the TU833 Extended Module Termination Unit, operates as a dedicated hardware component for field signal termination and ModuleBus signal routing within S800 I/O platforms.

Suffix Breakdown & Model Matrix

Hardware Specifications

Backplane Bus Communication Velocity & I/O Density Scaling

The ABB TU833 features integrated ModuleBus routing architecture that provides deterministic backplane bus communication velocity across the S800 I/O cluster. Internal signal propagation logic automatically shifts outgoing position signals to the subsequent ModuleTermination Unit, executing hardware-level I/O slot addressing without requiring software node configuration. Designed for high I/O density scaling, the unit routes up to 16 independent channel signals with integrated mechanical keying slots to prevent improper I/O module insertion into the backplane interface.

Frequently Asked Questions

Q: What happens to process field power if a process group fuse blows on the unit?

A: The ABB TU833 incorporates two individually isolated process voltage groups, each protected by an internal 6.3 A fuse. A blown fuse isolates power strictly to its designated group without interrupting field power distribution to the adjacent channel group or breaking ModuleBus communication continuity.

Q: Can the unit be mounted on standard DIN rails while maintaining system ground integrity?

A: Yes. The base houses an integrated mechanical latching mechanism designed for standard DIN-rail mounting. This latch secures the hardware physically and bonds the unit to the grounded DIN rail for EMC compliance.

Field Installation Guidelines

• DIN Rail Attachment: Fasten the unit to a standard grounded 35 mm DIN rail. Verify that the metallic latch clicks to achieve protective earth (PE) grounding continuity per Class I IEC 61140 requirements.
• Wiring Practices: Strip conductor ends to 6 mm. Terminate one solid or stranded wire per spring-case snap-in terminal (24 - 12 AWG / 0.2 - 2.5 mm2). Do not force multiple conductors into a single terminal point.
• Shielding & Grounding: Ground all field signal cable shields at the designated system grounding bar prior to termination at the unit. Keep field signal wiring separated from high-voltage AC lines to minimize noise induction.
• Mechanical Keying: Ensure the mechanical keying code matches the target S800 I/O module before slotting the module into the unit. Forceful insertion against keying slots can damage internal backplane pins.