The ABB TB806 3BSE008536R1 is a ModuleBus Cable Adaptor designed for the ABB S800 I/O system. It is used to extend the electrical ModuleBus so that S800 I/O modules connected to the same ModuleBus can be installed on different DIN rails.
Unlike an S800 I/O module or Module Termination Unit, the TB806 is a communication and interconnection accessory. Its primary function is to provide a ModuleBus inlet and connect the incoming ModuleBus extension cable to the S800 I/O assembly.
ABB specifies that the TB806 is used together with TB805 and TK801V0xx cables to extend the ModuleBus. It can also be used with TB842 to create an optical ModuleBus extension.
Product Information
| Item | Description |
|---|---|
| Brand | ABB |
| Model | TB806 |
| Article Number | 3BSE008536R1 |
| Product Type | ModuleBus Cable Adaptor |
| Series | ABB S800 I/O |
| Core Function | ModuleBus extension and bus inlet |
| ModuleBus Direction | In |
| Cable Interface | D-sub 25-pin male |
| Internal Interface | DIN 41612 Type R/4 |
| Mounting | DIN rail |
| Protection Class | IP20 |
| Dimensions | Approx. 17 × 13 × 19 mm |
| Weight | Approx. 10 g |
| Operating Temperature | 0 to +55 °C |
| Storage Temperature | −25 to +70 °C |
ABB’s current hardware selector identifies the TB806 as an S800 accessory with Article Number 3BSE008536R1. Current ABB documentation lists dimensions of approximately 17 mm wide × 13 mm deep × 19 mm high and a weight of approximately 10 g.
What Is the ABB TB806?
The TB806 is an S800 ModuleBus Cable Adaptor used when an S800 I/O installation needs to extend the ModuleBus between physically separated I/O assemblies.
In a conventional compact I/O arrangement, several modules can be installed next to each other on the same DIN rail. However, some control cabinet designs require I/O modules to be installed on separate DIN rails or in physically separated locations.
The TB806 provides the connection point required for this arrangement.
A simplified configuration is:
S800 I/O Station → TB805 → TK801 Extension Cable → TB806 → S800 I/O Modules
The TB805 functions as the ModuleBus outlet, while the TB806 functions as the corresponding ModuleBus inlet. The TK801 cable connects the two locations.
Main Functions of TB806
1. ModuleBus Extension
The primary purpose of TB806 is to extend the S800 ModuleBus.
With the appropriate extension cable, S800 I/O modules can remain on the same electrical ModuleBus even when they are physically installed on different DIN rails.
This provides greater flexibility when designing control cabinets and distributed I/O assemblies.
2. ModuleBus Inlet
The TB806 is specifically the inlet side of the ModuleBus extension.
ABB documentation identifies the TB806 as a Bus Inlet, while the TB805 is the corresponding Bus Outlet.
This distinction is important when replacing or ordering the component because TB805 and TB806 have different connector genders and different positions in the ModuleBus extension architecture.
3. D-sub 25-Pin Connection
The external ModuleBus connection uses a DB25 / D-sub 25-pin male connector.
The opposite end of the extension arrangement uses the corresponding TB805 connection, with the TK801 cable providing the physical link.
This makes TB806 particularly useful when existing S800 installations require additional I/O modules to be located away from the original I/O rail.
4. DIN Rail Installation
The TB806 is designed for DIN rail installation and includes the mechanical interface required for mounting within an S800 I/O installation.
Its very compact form factor helps minimize the amount of cabinet space required for the ModuleBus extension connection.
TB805 and TB806: What’s the Difference?
TB805 and TB806 are frequently mentioned together because they work as a pair in a ModuleBus extension.
| Feature | TB805 | TB806 |
| Article Number | 3BSE008534R1 | 3BSE008536R1 |
| Function | ModuleBus Cable Adaptor | ModuleBus Cable Adaptor |
| Direction | Bus Outlet | Bus Inlet |
| D-sub Interface | Female | Male |
| Connector | DB25 | DB25 |
| ModuleBus Extension | Yes | Yes |
| Typical Cable | TK801V0xx | TK801V0xx |
| System | S800 I/O | S800 I/O |
ABB’s system documentation identifies TB805 as the Bus Outlet and TB806 as the Bus Inlet, with one TB805 and one TB806 used with the appropriate TK801 extension cable.
This means that TB805 and TB806 are complementary components rather than interchangeable replacements.
TB806 and TK801 Extension Cable
The TB806 is normally used with the TK801 ModuleBus Extension Cable.
ABB lists several TK801 cable lengths, including:
| Cable | Article Number | Length |
| TK801V003 | 3BSC950089R1 | 0.3 m |
| TK801V006 | 3BSC950089R2 | 0.6 m |
| TK801V012 | 3BSC950089R3 | 1.2 m |
These cables use a D-sub 25-pin male-to-female connection and are designed specifically for ModuleBus extension.
The appropriate cable length can be selected according to the physical distance between the two S800 I/O assemblies.
TB806 and TB842
The TB806 can also be used together with TB842 when an optical extension of the ModuleBus is required.
This provides an alternative architecture for applications where an electrical cable extension is not suitable or where optical communication is preferred for the physical connection between I/O sections.
ABB specifically identifies TB806 + TB842 as an option for providing an optical extension of the ModuleBus.
ModuleBus Architecture
A typical electrical ModuleBus extension can be represented as:
S800 I/O Modules
↓
TB805 ModuleBus Outlet
↓
TK801 Extension Cable
↓
TB806 ModuleBus Inlet
↓
Additional S800 I/O Modules
This architecture allows the additional I/O modules to remain part of the same electrical ModuleBus while being physically installed on another DIN rail.
This is particularly useful when cabinet layout, wiring access, physical separation, or I/O grouping requirements make it impractical to install every module on one continuous DIN rail.
Technical Specifications
| Parameter | Specification |
| Model | TB806 |
| Article Number | 3BSE008536R1 |
| System | ABB S800 I/O |
| Product Type | ModuleBus Cable Adaptor |
| Function | ModuleBus Inlet |
| External Connector | D-sub 25-pin Male |
| Internal Connector | DIN 41612 Type R/4 |
| ModuleBus | Electrical ModuleBus |
| Rated Insulation Voltage | 50 V |
| Dielectric Test Voltage | 500 V AC |
| Maximum 5 V Current Distribution | 1.5 A |
| Maximum 24 V Current Distribution | 1.5 A |
| Protection Class | IP20 |
| Mounting | DIN rail |
| Operating Temperature | 0 to +55 °C |
| Storage Temperature | −25 to +70 °C |
| Relative Humidity | 5–95%, non-condensing |
| Width | Approx. 17 mm |
| Depth | Approx. 13 mm |
| Height | Approx. 19 mm |
| Weight | Approx. 10 g |
The current ABB datasheet confirms the TB806’s compact dimensions and 10 g weight. ABB’s installation documentation specifies the ModuleBus power distribution capability at up to 1.5 A for both 5 V and 24 V distribution, with a 50 V rated insulation voltage and 500 V AC dielectric test voltage.
Applications of ABB TB806
The TB806 is mainly used in S800 I/O installations where the physical layout requires ModuleBus extension.
Typical applications include:
- Distributed I/O Cabinets
Allows I/O groups to be installed on separate DIN rails while remaining connected to the same ModuleBus. - Large Control Cabinets
Provides additional flexibility when a single DIN rail cannot accommodate the complete I/O configuration. - Process Automation
Supports distributed S800 I/O arrangements in process control systems. - Power Generation
Useful for control cabinets where I/O modules need to be physically separated according to plant equipment or cabinet layout. - Oil and Gas Systems
Can help organize I/O modules into different cabinet sections while maintaining the ModuleBus connection. - Existing S800 I/O Expansions
Suitable when additional I/O modules need to be added to an existing installation without completely redesigning the original I/O architecture.
Environmental and Certification Characteristics
The TB806 is designed for industrial automation environments and is specified for an operating temperature range of 0 to +55 °C and storage temperatures from −25 to +70 °C.
ABB lists IP20 protection and compliance with industrial electrical and EMC requirements. The current ABB hardware selector also lists hazardous-location certifications including C1 Div 2 cULus, C1 Zone 2 cULus, and ATEX Zone 2, together with marine certifications from ABS, BV, DNV, and LR.
Physical Specifications and Customs Information
| Item | Specification |
| Product Dimensions | Approx. 17 × 13 × 19 mm |
| Net Weight | Approx. 10 g |
| Product Type | ModuleBus Cable Adaptor |
| Article Number | 3BSE008536R1 |
| HS Code | 853690* |
| Country of Origin | Confirm against supplied unit |
Because the TB806 is a dedicated electrical connection/interface component, HS classification can vary according to the importing country’s customs interpretation. 853690 may be used as a reference heading for other electrical apparatus for making connections to electrical circuits, but the final HS code should be confirmed with the customs broker before shipment.
What to Check Before Purchasing TB806
When sourcing an ABB TB806 3BSE008536R1, several details should be checked:
- Complete Article Number
Confirm 3BSE008536R1 rather than relying only on the TB806 model name. - Bus Direction
TB806 is the ModuleBus inlet. Do not confuse it with TB805, which is the outlet. - Connector Type
Confirm the required D-sub 25-pin male interface. - Extension Cable
Check whether the installation uses TK801V003, TK801V006, TK801V012, or another compatible cable. - Existing S800 Architecture
Verify that the component belongs to an S800 I/O ModuleBus extension arrangement. - TB805 Compatibility
If the application uses a standard electrical ModuleBus extension, verify the corresponding TB805 on the opposite side. - Condition
For used or refurbished components, inspect the D-sub connector, DIN rail locking mechanism, and housing. - Certification Requirements
For hazardous-area or marine applications, confirm that the supplied unit carries the required certification for the project.
Conclusion
The ABB TB806 3BSE008536R1 is a compact ModuleBus Cable Adaptor and Bus Inlet for the ABB S800 I/O system. Its main function is to extend the electrical ModuleBus so that S800 I/O modules can be physically installed on different DIN rails while remaining part of the same ModuleBus architecture.
Its most important characteristics are its ModuleBus inlet function, D-sub 25-pin male interface, compact DIN rail design, and compatibility with TB805 and TK801 extension cables. ABB also supports the use of TB806 with TB842 for optical ModuleBus extension.
For replacement procurement, the key identification combination is:
ABB TB806 + 3BSE008536R1 + ModuleBus Inlet + D-sub 25 Male + S800 I/O
It is important not to substitute TB806 with TB805, because the two components serve opposite sides of the ModuleBus extension connection.
Related Tags
ABB TB806, ABB 3BSE008536R1, TB806 ModuleBus Cable Adaptor, ABB S800 I/O, S800 ModuleBus, ABB ModuleBus Extension, ABB TB805, ABB TK801, ABB TB842, S800 I/O Spare Parts, ABB Automation Spare Parts, ABB Distributed I/O, ModuleBus Cable Adaptor, ABB I/O Accessories
