What Is the ABB TU847?
When your automation system demands high availability for field communication, the ABB TU847 3BSE022462R1 Module Termination Unit delivers a robust solution. This passive MTU enables redundant configuration of two CI840 or CI840A modules, ensuring uninterrupted data exchange even if one module fails. Designed for PROFIBUS DP-V1 networks, the TU847 simplifies station addressing with two rotary switches supporting addresses 0 to 99. Mechanical keying with 36 combinations prevents incorrect module insertion, protecting your investment.
Technical Specifications Breakdown
- Power Input: 24 V d.c. (19.2 – 30 V) ensures stable operation across typical industrial supplies.
- ModuleBus Current Distribution: Maximum 5 V at 1.5 A and maximum 24 V at 1.5 A supports connected modules without overload.
- Communication Protocol: PROFIBUS DP-V1 via DSUB9 connector for reliable fieldbus communication.
- Mechanical Keying: 36 different combinations guarantee only compatible modules are installed.
- Environmental Ratings: Operating temperature 0 to +55 °C (approvals +5 to +55 °C), storage -40 to +70 °C, IP20 protection, and 5–95% non-condensing humidity.
- Certifications: CE, UL 61010-1, cULus Hazardous Location Class 1 Zone 2, ATEX Zone 2, and marine certificates (ABS, BV, DNV-GL, LR).
Industry Applications
In process industries such as oil and gas, chemical, and power generation, the TU847 provides the redundancy needed for critical control loops. For example, a refinery using CI840A communication interfaces can rely on the TU847 to maintain PROFIBUS connectivity even during module replacement or failure. The wide operating temperature range and hazardous location approvals make it suitable for harsh environments.
Installation & Setup Guidance
Mount the TU847 vertically or horizontally on a DIN rail using the integrated latching device for locking and grounding. Connect the 24 V d.c. power supply to the designated terminals using wire sizes 0.25–2.5 mm² (24–14 AWG) with a recommended torque of 0.5–0.6 Nm and stripping length of 6–7.5 mm. Insert two CI840 or CI840A modules into the positions, ensuring mechanical keys match. Set the station address via the two rotary switches (0–99). Note that the TU847 requires space to the left for removal and cannot be replaced with power applied.
Maintenance & Reliability
As a passive unit, the TU847 requires minimal maintenance. Periodically inspect connections for tightness and verify that the DIN rail latch remains secure. The IP20 enclosure protects against solid objects but not moisture; keep the unit in a clean, dry environment. For G3 compliant environments, consider the TU847Z version. Regular testing of redundancy functionality ensures maximum uptime.
Compatibility & Integration
The TU847 integrates seamlessly with ABB CI840 and CI840A field communication interfaces via the electrical ModuleBus. It also supports an optional ModuleBus Optical Port TB842 connected through TB806. Two service tool ports (RJ45) allow easy diagnostics. The PROFIBUS DP-V1 protocol ensures compatibility with a wide range of PLCs and DCS systems.
Selection Guide & Purchasing Advice
Before ordering, verify that your system uses CI840 or CI840A modules and requires redundant field communication. The TU847 is available in a standard version (3BSE022462R1) and a G3 compliant version (TU847Z). SpareTechPLC stocks both variants and can advise on lifecycle status and availability. Ensure you have the correct mechanical keys for your module types.
Frequently Asked Questions
Q: Can the TU847 be used with non-redundant CI840 modules?
A: Yes, the TU847 supports both single and redundant configurations, but its design specifically enables hot redundancy for two modules.
Q: What is the maximum cable length for the PROFIBUS connection?
A: The provided data does not specify cable length; refer to the CI840/CI840A manual for PROFIBUS cabling guidelines.
Q: Does the TU847 require external power for the ModuleBus?
A: Yes, it requires a 24 V d.c. supply (19.2–30 V) to distribute power to the connected modules.
Q: Is the TU847 hot-swappable?
A: No, the TU847 cannot be replaced with power applied. Always disconnect power before removal.
Q: What certifications does the TU847 hold?
A: It holds CE, UL 61010-1, cULus Hazardous Location Class 1 Zone 2, ATEX Zone 2, and marine certificates (ABS, BV, DNV-GL, LR).
