Description
Product Overview
The SAAB 1891 708 is a rack module assembly associated with legacy SAAB, Saab-Scania and Stalectronic control equipment. The unit is identified by several related part numbers, including 8537 000-451, 8537 000-411 and 1891 700-1.
Available identification records show the assembly associated with Stal Refrigeration AB / Stalectronic equipment and include markings such as ACU/DLU and CU/MU Type A. Additional numbers found with the assembly include 8537 412-003, 8537 012-411 and 8537 412-002.
Because documentation for this legacy hardware is limited, the safest description is Rack Module / Module Rack rather than assigning an unsupported CPU, power-supply or I/O function to the complete assembly.
Product Summary
SAAB 1891 708 is intended for use as part of a compatible legacy control-system rack arrangement.
The rack provides the mechanical and electrical framework for the associated control-system hardware. Its multiple identification numbers are important when searching for a replacement because older SAAB/Stalectronic assemblies may be identified by either the 1891 series article number or the 8537 series part numbers.
The available product record identifies the unit as a SAAB Rack Module, with Sweden listed as the country of origin and an approximate weight of 15.770 kg.
Product Datasheet
| Parameter | Specification |
|---|---|
| Brand | SAAB |
| Main MPN | 1891 708 |
| Product Type | Rack Module / Module Rack |
| Part Number | 8537 000-451 |
| Part Number | 8537 000-411 |
| Related Article No. | 1891 700 / 1891 700-1 |
| Associated System | Saab-Scania / Stalectronic |
| Designation | ACU/DLU |
| Related Designation | CU/MU Type A |
| Related MK No. | 8537 412-003 |
| Related MK No. | 8537 412-002 |
| Related KK No. | 8537 012-411 |
| Software Marking | Code-A |
| PCB Marking | A 94V0 |
| Country of Origin | Sweden |
| Listed Weight | Approx. 15.770 kg |
| Listing Condition | Used |
The identification above is based on the actual product listing and available product records. Not every number in the table should be treated as an independent replacement part number; several are associated markings or references found on the assembly.
Identification and Part Numbers
When working with older SAAB/Stalectronic equipment, part-number identification is particularly important.
The main identification is:
1891 708
Other associated numbers include:
8537 000-451
8537 000-411
1891 700-1
Additional markings documented for the assembly include:
- 8537 412-003
- 8537 012-411
- 8537 412-002
- 1891 700
- 9101
- A 94V0
- Wt3
- Code-A
These markings can be useful when comparing photographs, cabinet drawings, maintenance records and existing spare parts.
Rack Module Function
The 1891 708 should be considered a rack-level hardware assembly.
A rack module in this type of legacy control architecture normally provides the physical mounting and interconnection arrangement required by the system’s internal control electronics. The actual function of the individual boards or subassemblies installed in the rack depends on the system configuration.
For this reason, it is not recommended to describe the complete 1891 708 assembly as a CPU, digital input module, analog input module or power supply unless the individual installed board has been positively identified.
Legacy Control-System Compatibility
The available records connect this hardware with Saab-Scania, Stal Refrigeration AB and Stalectronic equipment. The product is therefore most relevant to maintenance of existing legacy installations rather than new control-system projects.
For a replacement application, compare the complete assembly with the installed rack:
- Main part number
- Article number
- Rack layout
- Board positions
- Connector arrangement
- Individual board numbers
- Revision markings
- Wiring
- Software or system designation
- Existing cabinet documentation
Installation Considerations
Before replacing an installed 1891 708 rack, record the existing configuration.
Take photographs of the front and rear of the rack before disconnecting anything. Record every cable and connector position, including labels that may appear unrelated to the main 1891 708 identification.
A practical replacement procedure is:
- Isolate the associated equipment according to the site maintenance procedure.
- Record the rack identification and all visible part numbers.
- Photograph the complete wiring arrangement.
- Label cables before removal.
- Compare the replacement rack with the original.
- Inspect connectors and mounting hardware.
- Install the rack without forcing plugs or card guides.
- Reconnect cables according to the original documentation.
- Verify grounding and cabinet connections.
- Perform system-level checks before returning the equipment to service.
Maintenance
Legacy rack assemblies should be kept clean and dry.
During scheduled maintenance, inspect:
- PCB surfaces
- Card guides
- Backplane connectors
- Plug-in connectors
- Wiring terminals
- Mounting hardware
- Signs of corrosion
- Signs of overheating
- Damaged insulation
- Loose connections
- Contamination or dust accumulation
Connector oxidation is worth checking on equipment that has been stored for a long time. A visually clean rack can still have contact problems at older connectors.
Storage
For long-term spare storage, keep the rack in a dry, temperature-controlled environment.
Use ESD protection when handling exposed circuit boards. Avoid stacking heavy equipment directly on the rack or its connectors.
If the assembly is being stored as a critical spare, keep a record of:
- Main part number
- All associated part numbers
- Hardware revision
- Photographs
- Previous test results
- Storage date
- Packaging condition
This makes later identification much easier when the equipment is needed for an emergency replacement.
Replacement Guidance
The safest replacement reference is the complete identification combination:
1891 708
8537 000-451
8537 000-411
1891 700-1
A replacement should also be compared with the actual rack markings, because the same general equipment family may contain different board configurations.
Do not purchase solely on the basis of the 1891 708 number if the installation requires a specific internal board arrangement. Compare the physical assembly and all visible identification numbers before confirming compatibility.
Inspection Before Shipment
For a used rack module, inspection should cover both mechanical and electrical condition.
Recommended inspection points:
- Verify 1891 708 marking.
- Verify 8537 000-451 marking where present.
- Verify 8537 000-411 marking where present.
- Check 1891 700-1 identification.
- Photograph all labels.
- Inspect PCB surfaces.
- Check connectors for oxidation.
- Check card guides.
- Check mounting points.
- Inspect wiring terminals.
- Look for corrosion.
- Check for signs of overheating.
- Check for damaged components.
- Confirm the physical configuration against listing photographs.
- Perform functional testing where a compatible test system is available.
Condition
The specific eBay listing supplied for this product is marked Used. The listing identifies SAAB as the brand, 1891 708 as the MPN, 8537 000-451 / 8537 000-411 / 1891 700-1 as associated part numbers, Sweden as the country of origin, and approximately 15.770 kg as the listed weight.
The seller’s condition statement describes the item as previously used, with possible cosmetic wear, while indicating that it is operational.
FAQ
What is SAAB 1891 708?
It is a legacy SAAB Rack Module / Module Rack associated with SAAB/Stalectronic control equipment.
What are the other part numbers?
The assembly is associated with 8537 000-451, 8537 000-411 and 1891 700-1. Additional markings include 8537 412-002 and 8537 412-003.
Is 1891 708 a PLC CPU?
It should not automatically be classified as a PLC CPU. Available documentation identifies it as a Rack Module, and the specific internal function depends on the associated system configuration.
Is it related to Stalectronic equipment?
Yes. Available product records associate the assembly with Stalectronic and Stal Refrigeration AB equipment.
What should I check before ordering?
Compare the complete part-number combination, rack layout, connectors, internal boards, revisions and physical configuration with your existing unit.
Search Terms
SAAB 1891 708, SAAB 1891708, SAAB Rack Module, SAAB Module Rack, SAAB 8537 000-451, SAAB 8537 000-411, SAAB 1891 700-1, SAAB 1891 700, Saab Scania Rack Module, Stalectronic Rack Module, Stal Refrigeration Rack, ACU DLU Rack, CU MU Type A, 8537 412-003, 8537 412-002, 8537 012-411, SAAB Industrial Control, SAAB Automation Module, Legacy SAAB Control System
