Product Overview
The ABB AI843 Thermocouple/mV Input Module is a high-precision analog input module designed for demanding industrial temperature and millivolt measurements. With 8 differential input channels, it handles linear ranges from -30 mV to +75 mV and supports thermocouple types B, C, E, J, K, L, N, R, S, T, and U. A dedicated Pt100 channel serves as the cold junction reference, ensuring accurate readings across all channels.
This module supports both single and redundant operation, making it a versatile choice for critical control systems. Its 16-bit A/D converter delivers precise data, while continuous wire-break monitoring enhances system reliability.
Key Features & Benefits
- 8 differential input channels for thermocouple/mV signals
- Single or redundant operation for high availability
- Separate 4-wire Pt100 channel for cold junction compensation
- Supports thermocouple types B, C, E, J, K, L, N, R, S, T, U
- 16-bit resolution (A/D converter) for accurate measurement
- Input wire-break open-circuit monitoring
Technical Specifications
| Parameter |
Value |
| Article Number |
3BSE028925R1 |
| Type |
Analog Input |
| Signal Specification |
-30..75 mV linear, TC types B, C, E, J, K, L, N, R, S, T, U |
| Number of Channels |
8 |
| Redundancy |
Yes |
| Mechanics |
S800 |
| Resolution |
16 bits |
| Input Impedance |
> 1 MΩ |
| Isolation |
Groupwise isolated from ground |
| Error |
Max. 0.1% |
| Temperature Drift |
Typ. 10 ppm/°C, Max. 25 ppm/°C |
| Input Filter (rise time 0-90%) |
1.1 kHz |
| Update Cycle Time |
320 + 80 * (no of active channels) ms at 50 Hz, 267 + 67 * (no of active channels) at 60 Hz |
| Maximum Field Cable Length |
600 meters (656 yards) or max. 500 Ω |
| CMRR, 50Hz, 60Hz |
100 dB |
| NMRR, 50Hz, 60Hz |
> 40 dB |
| Rated Insulation Voltage |
50 V |
| Dielectric Test Voltage |
500 V a.c. |
| Power Dissipation |
1.5 W |
| Current Consumption +5 V Modulebus |
60 mA |
| Current Consumption +24 V Modulebus |
50 mA |
| Current Consumption +24 V external |
0 |
| Dimensions (W x H x D) |
45 mm x 119 mm x 102 mm (111 mm with connector) |
| Weight |
0.157 kg (0.35 lbs.) |
Applications
The ABB AI843 excels in temperature monitoring for chemical reactors, furnaces, and heat treatment processes. Its multi-type thermocouple support and cold junction compensation make it ideal for applications requiring accurate temperature profiling, such as in power generation or petrochemical plants.
In redundant configurations, the AI843 ensures uninterrupted operation in critical safety loops, minimizing downtime and enhancing process reliability.
Installation & Setup
Mount the AI843 on an S800 series DIN rail within a suitable I/O chassis. Connect thermocouples or mV sources to the corresponding MTU (TU818, TU830, TU833, TU842, TU843) using proper wiring practices. Configure each channel's measurement range via the control system. Ensure the cold junction Pt100 is correctly connected for accurate temperature readings.
Maintenance & Reliability
Regularly inspect wiring connections for signs of corrosion or looseness. Monitor front LEDs (Fault, Run, Warning) for operational status. Keep the module clean and within specified operating temperatures (0 to +55 °C) to ensure long-term stability. The AI843's robust design and diagnostics minimize unplanned maintenance.
Compatibility & Integration
The ABB AI843 integrates seamlessly with ABB S800 I/O systems and is compatible with MTUs TU818, TU830, TU833, TU842, and TU843. It supports redundant operation and is designed for use with ABB DCS platforms. The module uses a keying code BA for proper slot identification.
Selection Guide
Before purchasing, verify your system's compatibility with the AI843 and required MTU. Consider the number of channels and thermocouple types needed. For expert advice and genuine parts, choose PLC Source PRO as your supplier.