Description

ABB TU848 Module Termination Unit

Configured for redundant TB840/TB840A Optical ModuleBus Modem interfacing in the ABB S800 I/O system, the ABB TU848 3BSE042558R1 (TU848 Module Termination Unit) provides the physical and electrical termination interface for redundant ModuleBus connections, dual power inputs, and modem installation.

Hardware Specifications

Parameter	Specification
Model	TU848
Full Article Number	3BSE042558R1
Brand	ABB
Product Type	Module Termination Unit for redundant TB840/TB840A
System	ABB S800 I/O
ModuleBus Interface	Redundant electrical ModuleBus
Supported Modems	TB840 / TB840A
Power Input	24 VDC, 19.2 to 30 VDC
ModuleBus Current Distribution	5 V: max. 1.5 A; 24 V: max. 1.5 A
Power Consumption	2.5 W
Rated Insulation Voltage	50 V
Dielectric Test Voltage	500 VAC
Mounting	DIN rail, vertical or horizontal
Wire Size	Solid / stranded, 0.2 to 2.5 mm2 (24 to 12 AWG)
Operating Temp	0 to +55 deg C
Storage Temp	-40 to +70 deg C
Relative Humidity	5 to 95%, non-condensing
Ingress Protection	IP20, IEC 60529
Dimensions	124 mm x 186.5 mm x 47 mm
Weight	0.45 kg
Origin	Not specified in supplied data
Certifications / Standards	CE, EN 61010-1, UL 61010-1, ATEX Zone 2, cULus Hazardous Locations Class 1 Zone 2, Marine ABS, BV, DNV-GL, LR

Redundant ModuleBus and Modem Interface

The TU848 provides two modem positions for redundant TB840 or TB840A Optical ModuleBus Modems. Each modem has an associated power connection, while the MTU distributes the required ModuleBus supply to the installed modem arrangement.

The unit incorporates a redundant electrical ModuleBus interface for connection to redundant S800 I/O configurations. Therefore, the TU848 functions as the termination and mounting interface rather than as an active communication processor.

A rotary switch provides cluster address selection from 1 through 7. The setting must correspond to the applicable S800 I/O cluster configuration.

The mechanical keying system provides 36 configuration combinations. Consequently, the installed module type can be mechanically restricted according to the configured key position, reducing the possibility of installing an incompatible module.

Frequently Asked Questions

Q: Does the TU848 operate as an active ModuleBus communication module?
A: No. The TU848 is a passive Module Termination Unit. It provides physical termination, power distribution, modem mounting, and ModuleBus interconnection for TB840/TB840A modules.

Q: Can the TU848 support redundant TB840/TB840A configurations?
A: Yes. The TU848 is specified for redundant TB840/TB840A Optical ModuleBus Modem configurations and provides separate power connections for the redundant modem arrangement.

Q: What cluster address range can be configured on the TU848?
A: The integrated rotary switch supports cluster address settings from 1 through 7.

Field Installation Guidelines

1. Mount the TU848 on a suitable DIN rail and engage the integrated latching mechanism. Verify that the unit is mechanically secured and that the mounting arrangement provides the required protective grounding path.
2. Install the applicable TB840 or TB840A modems according to the configured mechanical keying. Confirm that the module key position matches the intended hardware configuration before insertion.
3. Connect the two 24 VDC supply circuits to their designated power terminals when implementing the redundant modem configuration. Observe the specified 19.2 to 30 VDC input range.
4. Keep ModuleBus and power wiring separated from high-current switching conductors and sources of electromagnetic interference where practical.
5. Use solid or stranded conductors within the specified 0.2 to 2.5 mm2 range. Secure each conductor according to the terminal manufacturer's applicable wiring practice.
6. Set the rotary cluster address before placing the assembly into service. Verify that the selected address corresponds to the S800 I/O cluster configuration.
7. Verify polarity, terminal assignment, module seating, mechanical keying, and redundant connections before energizing the assembly.
8. Maintain the specified operating environment of 0 to +55 deg C and 5 to 95% relative humidity, non-condensing. The enclosure rating is IP20; therefore, additional cabinet-level environmental protection may be required.

Specifications

• Brand: ABB

Advantages

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