Description

ABB TU851 Extended Module Termination Unit

Configured for field wiring termination, signal distribution, and ModuleBus interfacing in the ABB S800 I/O system, the ABB TU851 3BSE068782R1 (TU851 Extended Module Termination Unit) provides the physical termination interface for connected I/O modules.

Hardware Specifications

Parameter	Specification
Model	TU851
Brand	ABB
Product Type	Extended Module Termination Unit (MTU)
Part Number	3BSE068782R1
Series	ABB S800 I/O
Number of I/O Channels	16 I/O channels
Voltage Rating	> 250 V
Current Rating	> 3 mA per I/O channel
ModuleBus Connections	Supports connections to ModuleBus and I/O modules
Mounting Type	DIN rail mounting

ModuleBus and I/O Interface

The TU851 provides the physical interface between field wiring and the associated ABB S800 I/O modules. It supports ModuleBus connections and provides termination points for 16 I/O channels.

The specified voltage rating is greater than 250 V, while the specified channel current capability is greater than 3 mA per I/O channel. Therefore, installation should follow the electrical ratings of the complete I/O module and field circuit rather than treating the MTU as an independent signal-conditioning device.

Frequently Asked Questions (FAQ)

Q: Does the TU851 perform signal processing?

A: No. The supplied specifications identify the TU851 as an Extended Module Termination Unit. Its stated functions are field wiring termination, ModuleBus interfacing, and physical connection to S800 I/O modules.

Q: How many I/O channels does the TU851 support?

A: The supplied data specifies 16 I/O channels.

Q: Can the TU851 be installed on a DIN rail?

A: Yes. The supplied specifications identify DIN rail mounting as the mounting method.

Field Installation Guidelines

Install the TU851 on the specified DIN rail and verify that the mechanical mounting is secure before connecting field conductors.

Route field wiring so that signal conductors remain separated from high-energy power wiring where required by the site electrical installation standard. Avoid excessive mechanical force on terminal connections and maintain adequate conductor bending radius.

Connect ModuleBus and I/O wiring according to the applicable ABB S800 I/O system documentation and the electrical requirements of the associated I/O modules. Verify polarity, terminal assignment, and field-circuit voltage before energization.

The supplied data does not specify operating temperature, power consumption, dimensions, or weight. These parameters should therefore be confirmed from the applicable ABB hardware documentation before cabinet layout, thermal calculations, or logistics planning.

Specifications

• Brand: ABB

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems