AI890: Ex loop power, TU890/TU891 selection and channel verification
ABB AI890 incorporates intrinsic-safety protection for eight current-input channels. Its paired TU890 termination unit is identified for Ex applications, while TU891 is a non-Ex option; the approved loop design determines which assembly is allowed.
Verified identification and technical data
| Technical item | Verified value / selection note |
|---|---|
| Module | AI890 |
| Article number | 3BSC690071R1 |
| Channels | 8 single-ended current inputs |
| Signal | 0–20 mA or 4–20 mA family use |
| Intrinsic safety | Integrated channel protection |
| Resolution | 12 bit |
| MTU pairing | TU890 for Ex; TU891 for non-Ex applications |
| HART | No, according to ABB selector |
For AI890, the table is an identification and selection aid. A nameplate, ABB order record and the actual installation still govern the final configuration.
Confirm the full type, revision and installation limits before treating any related code as a replacement.
Application decision
Review the duty before choosing AI890. Treat every hazardous-area loop as an entity with cable parameters, transmitter certification, barrier calculations and installation rules. Do not infer Ex compliance from the module label alone.
The decision for AI890 should record actual load or process limits, operating environment, normal behavior and the response to a fault. This avoids a selection based only on a familiar series name.
Order and compatibility gate
When specifying AI890, Verify channel loop power, current range, field wiring, MTU type and site hazardous-area dossier. Check the ABB control drawing and any local approval limits for the full assembly.
Send the full designation AI890, hardware or serial revision, quantity, delivery need and nameplate photograph with the RFQ. Require written confirmation of any proposed successor or option-code change.
Installation and proving
For AI890, Follow the site's permit and isolation procedure before disturbing field wiring. After service, confirm each calibrated loop signal, fault diagnostic and documentation of the intrinsically safe circuit.
Record the as-left settings, test results and installed interfaces of AI890. Make the asset record searchable by the complete designation, not only by a short family label.
Same-series designation index
The codes below share a product family or an identified order-code relationship with AI890. They may differ in rating, software, connections, options or approvals; none is automatically interchangeable.
No additional same-series designation is shown for AI890; confirm the exact ordered assembly before purchase.
Handover record
The buyer and site engineer should agree on a single verified configuration for AI890, including accessories, documentation and the accepted test procedure. Keep deviations visible to both procurement and maintenance.
Retain AI890 in the purchase order, asset register and commissioning record. ABB family specifications help identify the device, but the approved project documents determine whether it is suitable for this installation.
