ABB TU838 Extended MTU Baseplate

Description

Key Technical Specifications

Product Introduction & Supply Chain Strategy

The ABB TU838 (3BSE008572R1) is an extended module termination unit (MTU) designed to streamline wiring topologies for S800 I/O components within the System 800xA control framework. Engineered with an expanded physical base, the TU838 provides a true 3-wire termination style per channel. This design allows field engineers to land the signal wire, return loop, and shield drain wire directly onto a single, dedicated hardware slot. This setup eliminates the need for external marshaling terminal blocks for analog transmitters and valves, saving valuable cabinet footprint.

From a lifecycle and maintenance perspective, procurement of this unit as a New Surplus asset directly minimizes your Total Cost of Ownership (TCO). Because the TU838 holds high-density analog connections, its internal backplane traces and screw blocks are highly susceptible to corrosion from atmospheric pollutants and stress-cracking from wiring changes. Refurbished baseplates present major operational hazards: microscopic breakdown within the channel isolation barriers or worn terminal threads can introduce signal noise and crosstalk into sensitive 4-20 mA current loops. Sourcing factory-clean, zero-hour surplus hardware guarantees pristine signal isolation and isolates your distributed network from unpredictable data timeouts.

TU838

TU838

Installation & Configuration Guide

Stage 1: Pre-Installation (Prep & Safety)

1. De-energize the local ModuleBus power supply and verify that all instrument field power loops running to this section of the cabinet are isolated.
2. Put on a grounded ESD wrist strap and connect its reference clamp to the bare copper cabinet grounding bar.
3. Configure the mechanical keying pegs on the face of the to match the exact profile of your target S800 I/O card to prevent inserting an incompatible module during the swap.

Stage 2: Removal

1. Unfasten the screw-clamp terminals, pull the 3-wire field instrument bundles back carefully, and verify all line tags match your panel drawings.
2. Disconnect adjacent MTU slots by prying the interlocking side-ModuleBus connectors outward.
3. Insert a flathead screwdriver into the lower plastic DIN rail release latch, pry downward, and swing the empty baseplate off the mounting rail.

Stage 3: Installation (Clone & Seat)

1. Hook the top mounting groove of the new surplus onto the 35 mm DIN rail, then snap the lower section inward until the rail latch locks tight.
2. Slide the module horizontally until its internal ModuleBus contacts mate completely into the adjacent MTU baseplate connector slot.
3. Terminate your field wiring back into the designated 3-wire terminal rows, torquing each connection firmly to prevent high-resistance points.

Stage 4: Power-On & Testing

1. Before plugging the electronic S800 I/O module onto the new baseplate, use a digital multimeter to check the terminal points and verify that field voltages match expected levels.
2. Align the target I/O module with the baseplate guide pins and slide it straight home until its plastic side latches lock into the frame.
3. Reapply primary control power and field power. Verify the module runs its startup sequence smoothly and that your central engineering workstation shows clear, error-free communication with the slot node.

Firmware/Software Versions & Upgrade Notes

The is a passive mechanical and electrical routing baseplate asset. It does not feature an onboard microprocessor, programmable flash memory blocks, or updateable firmware code. It functions independently of the software version driving your master AC 800M controller or field communication interfaces (such as the CI801 or CI840).

However, you must ensure that your Control Builder configuration matches the specific I/O module variants mounted to the baseplate. If your engineering software configuration expects a specific module variant (e.g., an AI830) but the physical mechanical keying on the blocks it from seating, the system will trigger a persistent hardware mismatch alarm. Always document your physical mechanical key positions during field upgrades to prevent configuration errors.

Frequently Asked Questions (FAQ)

Is this baseplate brand new or an item salvaged from an old panel?

This module is a guaranteed New Surplus item. It has never been installed in a working field panel, wired into an active system, or subjected to industrial warehouse pollution. It is clean inventory preserved in controlled storage conditions and opened only for our inbound quality check. We maintain a zero-tolerance policy for refurbished components.

What is the exact benefit of using a 3-wire MTU like the ?

The provides individual signal, return, and shield/ground points for each I/O channel on the baseplate itself. This eliminates the need to route separate return loops or shield drains to separate common grounding blocks elsewhere in the enclosure, drastically reducing cabinet complexity and simplifying loop troubleshooting.

What is the exact function of the small plastic wheels/pegs on the baseplate face?

These are mechanical coding keys. They are configured to establish a unique mechanical profile that matches only one specific type of S800 I/O card. This safety mechanism ensures that if a technician tries to plug an incompatible card into the slot during an emergency swap, the module will be physically blocked from seating, preventing electrical damage.

Can I run 120 V AC signaling directly through the terminals of this module?

No. The extended baseplate is rated for a maximum operational voltage threshold of 50 V. It is engineered strictly for low-voltage signaling applications, typically standard 24 V DC digital lines or analog instrument current loops. Running high-voltage AC lines through this unit will cause insulation breakdown and damage the internal bus pathways.

What type of warranty protection covers this hardware component?

We provide a comprehensive 1-year warranty on this New Surplus module termination unit, starting from the day it leaves our warehouse. This matches standard OEM protection parameters, giving your maintenance team complete peace of mind.