ABB 3KDE175111L9210 TU921S S900 I/O Redundant Termination Unit

Description

The TU921S (TU16R-Ex) is a high-reliability, redundant Module Termination Unit (MTU) designed for the S900 I/O remote architecture, supporting up to 16 I/O modules. This termination unit is engineered to streamline field installation by mounting directly in non-hazardous locations or hazardous areas classified up to Zone 1, lowering engineering costs by minimizing traditional marshalling and trunk cabling requirement loops.

The S900 Type S framework interfaces with control platforms via standard PROFIBUS DP communication protocols and enables connection to intrinsically safe field instruments situated across Zone 2, Zone 1, or Zone 0 explosive atmospheres. Featuring built-in infrastructure for redundant communication and system power, the unit incorporates integrated disconnection switches to enable real-time replacement of power modules without interrupting underlying primary circuit current loops. Each subassembly features complete environmental G3-coating, supporting full Hot Swap capability, Hot Configuration in Run (HCIR), and intelligent auto-diagnostics managed seamlessly over FDT/DTM tools.

Features

• Accommodates up to 16 active S900 I/O modules on a single footprint base
• Engineered with full hardware infrastructure readiness for redundant system power and communication lines
• Certified with ATEX approval ratings enabling physical deployment directly in Zone 1 environments
• Provides up to 4 terminal attachment connections per independent fieldbus channel
• Enables Hot Swap module replacement and Hot Configuration in Run (HCIR) during live plant operations
• Advanced diagnostics and field device parametrization supported via standardized FDT/DTM utilities
• Full-board G3-coating protection to withstand harsh, corrosive atmospheric pollutants
• Integrated manual preselection switches for direct fieldbus hardware address assignment
• Shipped standard with accompanying CD910 components and configured for placement in certified field housings

Applications

• Remote S900 I/O field stations located in Zone 1 or Zone 2 hazardous areas
• Intrinsically safe field instrument loop aggregation (Zone 0/1/2 environments)
• Redundant PROFIBUS DP industrial network distribution links
• Chemical process lines, refining plants, and offshore oil and gas setups

Ordering Information

TU921S: Redundant Termination Unit (TU16R-Ex) base module.

3KDE175111L9210: Complete ordering model identifier (includes accompanying CD910 kit assembly).

Technical Specifications

Installation Guidelines

• Hazardous Site Precautions: When implementing a Zone 1 installation layout, mount the unit safely inside a certified field housing assembly that complies with structural environmental explosion-proof demands.
• Address Preselection: Use the manual address adjustment switches onboard the unit to set the unique PROFIBUS DP node address value before securing the primary communication lines.
• Power Isolation Segregation: Although the unit features integrated isolation components that permit online power supply swap-outs, observe safety rules when handling input lines inside volatile environments.
• Grounding Requirements: Secure the heavy structural backplane frame cleanly to the enclosure reference earthing plate to keep low-impedance pathways clear and maintain optimal intrinsic safety barriers.
• Cable Routing Density: Arrange the field terminal lines using the 4-terminal-per-channel grid layout smoothly to prevent stress on terminal clamp springs.

Compliance and Certifications

• ATEX Certification for Zone 1 deployment
• EU Directive 2011/65/EU (RoHS alignment)

FAQ

What specific field zone devices can wire into this termination unit?

The unit can interface directly with intrinsically safe field devices that reside in Zone 2, Zone 1, or Zone 0 hazardous locations, provided the chassis base unit is powered under the S900 Type S system rules.

Is it necessary to switch off the main feed to replace a power module?

No, integrated isolation mechanics allow individual power supply blocks or communication modules to be replaced without turning off the primary supply lines.

What function does the G3-coating provide for industrial installations?

The G3-grade coating acts as a protective layer over all electronic tracks, protecting the board against moisture, conductive dust, and corrosive gas environments.

How is the device station network identity established on this backplane?

The backplane has on-board physical address switches, allowing installers to set the fieldbus node index value before activating the system loop.

What is the precise standalone structural weight profile of this terminal foundation?

The net standalone weight of this subassembly is 3.79 kg, reflecting its robust build and scale for 16-channel card integration.