Description
Note: Many products are not yet listed. Please contact us for more product information. Our supply channels are constantly expanding, and we currently have 20 stable shared supply channels. Please confirm the model, product, price, and all other necessary information with customer service before placing an order. We offer new, refurbished, and used products, and prices are adjusted according to the year of the item you require.
Product Introduction
When your compact industrial automation control system needs a reliable and space-saving PLC installation base, this chassis acts as the core physical carrier and backplane communication foundation for the entire SLC 500 PLC system.
It features a rugged all-metal frame with built-in module latching rails that firmly secure all installed modules, preventing loose connection faults caused by industrial site vibration. Its passive ventilation design eliminates the need for cooling fans, reducing system maintenance points and extending long-term operation reliability. It supports cascading up to 3 chassis to expand the total I/O count to 30 points, easily adapting to small and medium-sized automation control requirements.
1746-A4
1746-A4
Key Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 1746-A4 |
| Product Type | SLC 500 Modular PLC 4-Slot I/O Chassis |
| Total Slots | 4 slots total (1 dedicated for power supply, 3 for processor/I/O/communication modules) |
| Backplane Function | High-speed parallel backplane for data transfer between all installed modules |
| Mounting Options | DIN 35mm standard rail mounting / direct panel mounting dual support |
| Construction | Durable heavy-duty metal frame with reinforced module latching rails |
| Cooling Design | Passive natural ventilation, no cooling fan required |
| Expansion Capability | Supports cascading up to 3 chassis to a single SLC 500 processor for 30 total I/O points |
| Operating Temperature Range | 0°C ~ +60°C |
| Net Weight | ~2.27 kg (5.0 LBS) |
| Industry Certifications | GOST, KC, Marine industrial safety certified |
| Compatible Systems | Allen-Bradley SLC 500 series modular PLC systems |
Field Application & Technical Pitfalls
Critical Industrial Scenarios
- **Small Material Handling Conveyor Control: Acts as the compact installation base for small material handling conveyor PLC control systems, providing stable backplane communication for the processor and digital I/O modules.
- **Packaging Machine Automation Control: Delivers reliable chassis support for small packaging machine PLC control systems, adapting to limited installation space requirements on packaging equipment.
- **Small Water Treatment Plant Process Control: Adapts to humid industrial water treatment plant environments, providing stable physical carrier for small process control PLC systems.
Non-Negotiable Technical Pitfalls
- ⚠️ Bold Warning 1: Never install the chassis in a location with severe continuous vibration exceeding 2G. The third module latching rail will experience fatigue deformation that causes loose backplane connection faults.
- ⚠️ Bold Warning 2: Skipping the pre-commissioning full backplane communication test will leave you with hidden slot communication dead zones. This unit must complete full-slot module insertion test to ensure all 4 slots support normal data communication.
- ⚠️ Bold Warning 3: Do not mix SLC 500 series modules with non-SLC 500 PLC modules in this chassis. The backplane bus will experience signal conflict that causes the entire PLC system to crash.
A packaging machine maintenance team once swapped a 1746-A4 chassis and skipped the full backplane communication test. The hidden dead slot caused the analog I/O module to lose communication with the processor, resulting in a 1.5-hour packaging machine production downtime.
1746-A4
1746-A4
1746-A4
Quality Control (QC) SOP & Transparency
- Inbound Verification: Cross-check the OEM serial number against Rockwell Automation’s official SLC 500 part registry, confirm the part number 1746-A4 matches the factory label, and inspect no deformation or corrosion on the metal frame and backplane connectors.
- Live Rig Testing: Install a full set of SLC 500 processor, power supply and I/O modules into the chassis, power on the system, and confirm full backplane communication stability for 2 continuous hours.
- Parameter Testing: Verify all 4 slots support normal module identification and data communication, confirm DIN rail and panel mounting structures are intact, and validate all module latching rails function properly.
- Final QA & Packaging: Seal the tested chassis in a heavy-duty industrial carton with foam padding, attach a unique QC passed serial label, and complete the final packaging for shipment.
Frequently Asked Questions (FAQ)
- Can I hot-swap I/O modules in this chassis while the SLC 500 PLC system is running? Yes, but you must first confirm the corresponding I/O module supports hot-swap functionality, otherwise you will trigger temporary I/O signal loss alarms.
- What exact systems is this chassis compatible with? It works natively with Allen-Bradley SLC 500 series modular PLC systems. It will not support installation of ControlLogix or CompactLogix series modules.
- How long is the standard warranty for this new surplus unit? 12 months from delivery. It covers all manufacturing defects, but does not extend to units damaged by physical impact, miswiring, or improper module insertion in the field.
- How do I tell a genuine OEM unit apart from a refurbished clone? Genuine Allen-Bradley 1746-A4 chassis have a laser-etched part number on the metal frame, not a printed sticker. Clone units almost always fail the full 4-slot backplane communication stability test.
- What is the typical lead time for shipment? In-stock units ship within 48 hours. If you require official Rockwell Automation factory compatibility test documentation, add 2 extra business days to the turnaround window.
- Can this chassis replace the older SLC 500 legacy 4-slot chassis unit? Well, technically it is fully pin-compatible with the legacy unit, no extra configuration work is required, you can directly swap the modules from the old chassis to this new unit.
