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Phone: +86 16626708626Description
Key Technical Specifications
- Catalog Number: 1746-OA16
- Manufacturer: Allen-Bradley
- Product Family: SLC 500
- Module Type: Digital AC output module
- Output Count: 16
- Output Type: Triac, AC
- Output Voltage Range: 85-265 VAC
- Nominal Output Voltage: 120/240 VAC
- Points per Common: 8
- Backplane Current at 5 VDC: 0.37 A
- Off-State Leakage: 2 mA max
- Continuous Current per Point: 0.5 A at 30 °C
Product Introduction
The Allen-Bradley 1746-OA16 is a 16-point AC output module for the SLC 500 PLC family. It switches 120/240 VAC loads through triac outputs for devices such as pilot lights, contactors, and solenoid circuits that run on AC power.
This module is used in legacy SLC 500 panels that need 16 AC outputs in two 8-point commons. The 1746-OA16 supports 85-265 VAC operation, so it fits a wide range of AC load applications without changing the original rack layout.
1746-OA16
1746-OA16
Troubleshooting Quick Reference
| Symptom | Possible Cause | Relevance to this Part | Quick Check Method | Recommendation |
|---|---|---|---|---|
| Output never turns on | No field AC power or no PLC command | ✅ High | Measure 85-265 VAC at the load circuit and check the output bit | Verify control power and program logic first |
| LED on, load stays off | Open load, blown fuse, or wiring fault | ✅ High | Check continuity through the load and fuse | Inspect the external circuit before replacing the module |
| Output stays partially on | Off-state leakage or wrong load type | ✅ High | Measure leakage current and confirm load impedance | Use the correct load and verify the triac output is suitable |
| Several outputs dead | Common feed missing | ✅ High | Check the common terminal and upstream AC supply | Restore the common feed first |
| Load chatters or hums | Inductive load without proper suppression | ⚠️ Medium | Inspect the load type and suppression hardware | Add snubber or suppression as needed |
| Module runs hot | High current load or poor cabinet ventilation | ⚠️ Medium | Measure actual load current and cabinet temperature | Reduce loading and verify airflow |
If you are stuck, send photos of the wiring, common terminals, and processor diagnostics to technical support.
Frequently Asked Questions
Q: What does the 1746-OA16 do?
It is a 16-point AC output module for the SLC 500 family. It switches AC loads from the PLC.
Q: Is it a relay output module?
No. This is a triac-based AC output card. If you need dry contacts, use a relay output module instead.
Q: What voltage does it switch?
It is rated for 85-265 VAC, with 120/240 VAC as the nominal class.
Q: Is this part still made by Rockwell?
No. It is a discontinued SLC 500 module, so most inventory is surplus or refurbished.
Q: How many outputs share a common?
Eight points per common, so the module is split into two output groups.
Q: What usually causes false blame on the module?
A blown fuse, open load, missing common, or a downstream device that is not AC-rated. Those are common field issues.
Q: What should I verify before ordering?
Check the exact part number, the AC voltage class, the load type, and the common wiring. The biggest mistake is using it where a relay contact output is actually required.
