Description

1. Product Overview

ABB TU837V1 (Part No.: 3BSE013238R1) is an extended 8-channel module terminal mounting base (MTU Terminal Unit) belonging to the S800 I/O series. It is compatible with the AC 800M DCS distributed remote I/O control system. As a dedicated passive wiring base for field instrument cables and high-voltage analog and digital I/O modules, it adopts the built-in ModuleBus backplane bus to realize daisy-chain networking of multiple bases. Meanwhile, it can automatically assign a unique hardware address to the I/O module installed in each slot without manual DIP switch setting, which greatly reduces the probability of on-site configuration errors.

This terminal unit has a maximum withstand voltage of 250V and a rated load current of 3A per channel. Each channel is equipped with an independent fuse protection structure, supporting two signal wiring modes: isolated mode and grouped mode. Fitted with mechanically coded anti-misplug lock strips, it physically prevents short-circuit burnout faults caused by incorrect insertion of different types of I/O modules. Designed for bidirectional mounting on standard 35mm DIN rails, it features wide-temperature operating performance and Industrial Class A electromagnetic compatibility. It is widely used in high-voltage measuring point signal collection scenarios in process industries including thermal power, chemical, metallurgy, oil & gas and water treatment. Typical applications include wiring for new high-voltage I/O measuring point projects, spare part replacement of legacy extended S800 terminal bases, as well as renovation and upgrading projects for measuring point expansion of control systems.

2. Hardware Structure and Composition

2.1 8-Channel Fused Field Signal Wiring Unit

It integrates 8 independent process signal wiring terminals. Each channel is provided with two sets of wiring terminals and an independent loop fuse, enabling safe connection of AC and DC field device cables such as solenoid valves, valve position feedbacks, high-voltage transmitters and relays. Two sets of electrically isolated common process power terminals are reserved to support either independent isolated signal wiring for single channels or grouped common power supply wiring. It is compatible with 2-wire, 4-wire instruments as well as field 220VAC digital equipment wiring. The signal terminals accept 0.2~6mm² solid wires and 0.2~4mm² stranded wires; the power return terminals accept 0.2~4mm² solid wires and 0.2~2.5mm² stranded wires. Standard torque crimping can withstand continuous plant vibration and eliminate faults such as loose wiring and signal disconnection.

2.2 ModuleBus Backplane Bus Daisy-chaining & Automatic Addressing Unit

A high-speed passive ModuleBus backplane transmission loop is built in, supporting end-to-end daisy-chaining of multiple TU837V1 units. It receives bus signals from the previous terminal base and transmits signals to the next one, allowing multiple sets of I/O measuring points to be connected to a single bus link. Hardware addresses are automatically assigned via displacement encoding signals, enabling the controller to accurately identify each I/O channel. Manual DIP switch setting and software address configuration are omitted, effectively avoiding commissioning problems such as duplicate addresses and misassigned measuring points, and shortening the overall commissioning period of remote I/O stations.

2.3 Mechanically Coded Anti-misplug Safety Positioning Unit

It is equipped with two groups of adjustable mechanical coding lock strips with 6 adjustable positions each, providing a total of 36 hardware positioning combinations. Exclusive physical lock positions are configured for various high-voltage DI, DO, AI and AO I/O modules, so only modules with matching codes can be inserted into the corresponding slots. This prevents power loop short circuits and chip breakdown caused by mixed use of low-voltage and high-voltage modules. It is especially suitable for high-density control cabinets with mixed high and low voltage measuring points, lowering the risk of man-made hardware damage during installation and maintenance.

2.4 DIN Rail Mounting & Shielded Earthing Protection Unit

The base adopts a snap-on rail locking structure that can be unlocked and disassembled with a screwdriver, supporting both horizontal and vertical cabinet mounting methods. Integrated dedicated earthing contacts realize full-unit shielded earthing when mounted on an earthed DIN rail, effectively suppressing common-mode electromagnetic interference. The enclosure is made of flame-retardant high-temperature resistant engineering plastic with physically separated strong and weak current wiring areas. This extended series of MTU bases is backward compatible in both hardware and software, allowing direct on-site replacement of legacy terminal units of the same specification without large-scale modification to existing cables and rail layouts.

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3. Technical Specifications

3.1 Electrical Specifications

Rated Withstand Voltage: Max. 250VAC/DC; dielectric withstand test: 2000VAC
Rated Current per Channel: 3A; maximum allowable current for common process loops: 10A
Per-channel Configuration: Dual wiring terminals + independent loop fuse for each channel
Compatible Cable Specifications: Signal terminals: solid wire 0.2~6mm², stranded wire 0.2~4mm²; power return terminals: solid wire 0.2~4mm², stranded wire 0.2~2.5mm²; standard crimping torque: 0.5~0.6N·m, wire stripping length: 7~8mm
Bus Type: Passive ModuleBus backplane daisy-chain bus, no external power supply required
Compatible Modules: High-voltage extended AI, AO, DI, DO I/O modules of the S800 series
Number of Channels: 8 independent fused process signal channels

3.2 Environmental Specifications

Operating Temperature (Horizontal Mounting): 0℃ ~ +55℃; Operating Temperature (Vertical Mounting): 0℃ ~ +40℃
Storage & Transportation Temperature: -40℃ ~ +70℃
Relative Humidity: 5%~95% RH, non-condensing, free of corrosive gas and conductive dust
Protection Class: IP20, only for installation in indoor ventilated and enclosed industrial control cabinets

3.3 Mechanical Specifications

Mounting Method: Bidirectional snap-on mounting on standard 35mm DIN rails
Overall Dimensions: W 120.5mm × D 64mm × H 110mm
Net Weight: Approx. 0.37kg
Enclosure Material: Flame-retardant high-temperature resistant engineering plastic
Optional Accessories: S800 series high-voltage I/O modules, shielded signal cables, DIN earthing rails, dedicated replacement fuses, terminal marking tags

4. Product Functions and Features

Independent Single-channel Fuse Protection for Short-circuit Safety of High-voltage Measuring Points

Each signal channel is fitted with an independent fuse. In the event of a short circuit or overload fault in a single loop, only the fuse of the faulty channel will blow, without cutting off power to the entire I/O module or bus loop. Normal data collection of other measuring points can be maintained, greatly limiting the scope of fault impact. It is ideal for wiring field high-power equipment such as 220VAC solenoid valves and high-voltage valve feedback devices.

Dual Isolated Common Power Supply Design for Flexible Compatibility with Multiple Instrument Wiring Schemes

Two sets of electrically isolated common process power terminals are provided. Multiple instruments can share one power supply, or analog and digital measuring points can be powered separately to effectively suppress crosstalk from high-power loops to low-power instrument signals. It meets complex field wiring requirements for mixed deployment of 2-wire transmitters and AC actuators.

Automatic Bus Addressing + Daisy-chaining for Rapid Networking of Large-scale Remote I/O

No manual DIP switch address setting is required. Multiple terminal bases can be extended via end-to-end daisy chaining, enabling centralized deployment of multiple 8-channel measuring points on a single ModuleBus bus. The controller automatically identifies all I/O points to reduce manual configuration errors, suitable for large-scale central remote signal collection projects with numerous measuring points.

Physical Coding Anti-misplug Design for Hardware Safety Protection in Mixed High/Low Voltage Cabinets

Mechanical locking restricts installation to only matching I/O modules, eliminating mixed use of high-voltage and low-voltage cards and preventing power short circuits and module burnout at the hardware level. It significantly improves operational safety during on-site installation and equipment maintenance in control cabinets densely arranged with high and low voltage measuring points.

Wide-temperature Bidirectional Industrial-grade Mounting Design for Long-term Stable Operation Under Harsh Conditions

Supporting both horizontal and vertical cabinet layouts, the flame-retardant sealed enclosure with shielded earthing enables the PCB to resist dust, humidity and electromagnetic radiation from frequency converters. Its wide-temperature performance adapts to high-temperature and dusty plants such as metallurgical, thermal power and chemical facilities. Hot swapping of same-series modules is supported, so maintenance does not require shutdown of all connected measuring points.

5. Applicable Working Conditions and Application Scenarios

Wiring of high-voltage remote I/O stations for AC800M DCS systems in petroleum refining and coal chemical plants, for centralized wiring of 8-channel measuring points including 220V solenoid valves, valve switch feedbacks, high-voltage temperature and pressure transmitters.
High-power DI/DO measuring point wiring for auxiliary control systems such as boilers, desulfurization, denitrification and water treatment in thermal power plants and waste incineration power plants, as well as high-voltage instrument signal conversion projects for local control cabinets.
Signal collection and wiring projects for high-voltage field equipment such as motor auxiliary feedback devices and pneumatic actuators in sequential interlock control systems of metallurgical, cement and papermaking production lines.
New construction and capacity expansion renovation of high-voltage measuring points for automatic control systems in municipal sewage and water supply plants, applicable to intensive wiring and installation scenarios for isolated instruments.

ABB TU837V1 3BSE013238R1 MTU Terminal Unit