ABB TB846 3BSE021439R1 AC 800M CEX Bus Terminal Base

The ABB TB846 3BSE021439R1, also cataloged as the TB846 Module Terminal Base, operates as a dedicated hardware component for mechanical mounting and electrical interface distribution within ABB AC 800M and System 800xA controller platforms. It hosts communication interface modules such as the CI853, CI854, CI860, and CI870, routing 24 VDC operational power and CEX bus signals directly to mounted hardware while enabling dual-redundant interface topologies across the backplane.

Hardware Specifications

Backplane Bus Communication Velocity and Redundant Hardware Execution

The TB846 baseplate provides low-latency CEX bus interconnection to maintain backplane bus communication velocity between communication modules and the central AC 800M controller. Designed to support hot-swappable module operations, the internal contact structures allow live insertion and removal of primary or redundant communication cards without interrupting backplane power distribution or corrupting active data packets on adjacent slots. The ISA G3 compliant housing protects signal paths against atmospheric corrosion in harsh electrical panel environments.

Frequently Asked Questions

Q: Which ABB communication interface modules are compatible with the TB846 baseplate?

A: The TB846 accommodates AC 800M CEX bus communication modules, including the CI853 (RS-232), CI854 (PROFIBUS-DP), CI860 (FOUNDATION Fieldbus HSE), CI870 (PROFINET), CI871, CI873, and CI874.

Q: Does the TB846 terminal base require independent power wiring for each slot?

A: No. The TB846 routes 24 VDC power directly from the AC 800M processor or adjacent baseplates via internal CEX bus pass-through lines, distributing power automatically to installed communication modules.

Field Installation Guidelines

Mount the TB846 baseplate onto standard 35 mm DIN rails, ensuring the metal grounding clips on the rear housing make firm, unpainted contact with the metal rail surface. Interlock the unit laterally with adjacent CEX bus baseplates until the internal connector pins fully lock together, forming an unbroken bus structure.

Verify that all module retention latches snap securely when seating interface modules into the TB846 slot. Route incoming communication network cabling away from AC motor conductors, and ensure shielded field wires connect to the system ground bus with short, low-impedance grounding connections.