ABB TB846 Dual Modulebus Inlet Module for Redundant I/O Extensions

Product Overview

Industrial automation has evolved from rigid, centralized control to flexible, distributed architectures. The ABB TB846 3BSE021439R1 Dual Modulebus Inlet Module embodies this shift, enabling engineers to extend the ModuleBus for redundant I/O systems. Designed for the S800 I/O series, this module works with TB845 and two TK801V0xx cables to place I/O modules on different DIN rails while maintaining electrical continuity. It also supports optical extensions when paired with TB842, making it a versatile building block for scalable control networks.

Technical Specifications

The TB846 operates reliably in demanding environments. It carries CE marking and complies with electrical safety standards IEC 61131-2, UL 61010-1, and UL 61010-2-201. For hazardous locations, it holds certifications for C1 Div 2 cULus, C1 Zone 2 cULus, and ATEX Zone 2. Marine certifications include ABS, BV, DNV, and LR. The operating temperature range is 0 to +55 °C, with storage from -25 to +70 °C and relative humidity 5 to 95% non-condensing per IEC/EN 61131-2. Pollution degree is Degree 2 per IEC 60664-1, and corrosion protection meets ISA-S71.04 G3. Protection class is IP20 per IEC 60529. EMC compliance follows EN 61000-6-4 and EN 61000-6-2. Overvoltage categories adhere to IEC/EN 60664-1, and equipment class is Class I per IEC 61140 (earth protected). RoHS compliance covers EU, UAE, and CN RoHS. Dimensions are 43 mm width, 31.5 mm depth, and 186 mm height, with a weight of 180 g.

Industry Applications

In process industries such as oil and gas, chemical, and marine, the TB846 supports redundant I/O configurations that minimize downtime. For example, a refinery can mount I/O modules on separate DIN rails to isolate critical loops, while the TB846 maintains a reliable ModuleBus connection. In marine applications, its ABS, BV, DNV, and LR certifications ensure compliance with stringent shipboard standards. The ability to extend the ModuleBus optically with TB842 also suits environments requiring electrical isolation between cabinets.

Installation & Setup Guidance

Mount the TB846 on a standard DIN rail within the S800 I/O system. Connect it to TB845 and two TK801V0xx cables to extend the ModuleBus. For optical extensions, pair it with TB842. Ensure the module is properly earthed per Class I requirements. Verify that the operating environment stays within 0 to +55 °C and that humidity remains below 95% non-condensing. No special tools are required for installation.

Maintenance & Reliability

The TB846 requires minimal routine maintenance. Periodically inspect the module for dust accumulation and ensure ventilation openings remain clear. Check that all cable connections are secure and that the DIN rail mounting is stable. Given its IP20 protection, avoid exposing the module to liquid ingress or excessive dust. The wide storage temperature range (-25 to +70 °C) allows safe offline storage. Regular visual inspections help maintain long-term reliability in harsh industrial environments.

Compatibility & Integration

The TB846 is part of the ABB S800 I/O series and integrates seamlessly with ABB control systems. It works with TB845 and two TK801V0xx cables for electrical ModuleBus extension, and with TB842 for optical extension. This flexibility allows engineers to design redundant I/O architectures that span multiple DIN rails or cabinets. The module supports both standard and hazardous location installations, making it suitable for a wide range of automation platforms.

Selection Guide & Purchasing Advice

Before purchasing the ABB TB846, verify that your system requires ModuleBus extension for redundant I/O. Confirm compatibility with existing TB845 and TK801V0xx components. Check environmental conditions to ensure they fall within the specified operating range. BluePLC Industrial offers the TB846 with full warranty and fast shipping. Contact our team for current availability and lifecycle status before ordering.