1746-OA8 | Allen-Bradley Discrete AC Output Module Supplier

Introduction to the 1746-OA8

When your SLC 500 system needs robust AC output control, the 1746-OA8 offers a proven solution. This discrete AC output module from Allen-Bradley, manufactured by Rockwell Automation, provides eight output channels organized into two groups of four channels each. It delivers an output voltage range of 85-264 VAC at 47-63 Hz, drawing 185 mA from the 5 VDC backplane.

Key Features & Technical Specs

• Eight output channels in two isolated groups of four for flexible wiring.
• Nominal output voltage of 120/240 VAC with a range of 85-264 VAC.
• Continuous current per point: 1.00 A at 30 °C (86 °F); derates to 0.5 A at 60 °C (140 °F).
• Continuous current per module: 8.0 A at 30 °C; derates to 4.0 A at 60 °C.
• On-state voltage drop of 1.5 V maximum at 1.0 A ensures efficient operation.
• Surge current per point of 10 A for 25 ms handles momentary loads.
• ON signal delay of 1 ms maximum and OFF signal delay of 11 ms maximum for resistive loads.
• Step response of 60 ms in and 2.5 ms out for predictable switching.

Applications & Use Cases

Engineers commonly deploy the 1746-OA8 in general-purpose industrial automation tasks. For example, in a packaging line, this module can control AC solenoids and motor starters with its 1 A per point rating at 30 °C. Additionally, its two-group isolation allows mixing different voltage phases safely. Because of its 8 A per module capacity, it suits applications requiring moderate current switching across multiple outputs.

Installation & Setup

Integrating the 1746-OA8 into an SLC 500 chassis is straightforward. First, ensure the chassis backplane supplies 5 VDC and the module draws 185 mA. Then, wire each group’s common and output terminals according to your load requirements. Use the derating curves for continuous current per point and per module when operating above 30 °C. Always follow the Allen-Bradley installation manual for proper grounding and surge protection.

Maintenance & Reliability

To maximize the service life of the 1746-OA8, perform periodic visual inspections for signs of overheating or loose connections. Keep the ambient temperature within the rated 60 °C limit to maintain full current capability. Because the module uses solid-state switching, it offers high reliability compared to electromechanical relays. Regularly verify that the backplane current remains within the chassis power supply capacity.

Compatibility & Integration

The 1746-OA8 is part of the SLC 500 family and fits any SLC 500 chassis with a backplane. It works with Allen-Bradley SLC 500 processors and can be programmed using RSLogix 500 or similar software. The module uses positive logic (true when output is energized) and responds to standard ladder logic instructions. For system expansion, it integrates seamlessly with other 1746 I/O modules.

Troubleshooting & Common Issues

If an output channel fails to energize, first check the module’s status indicators and verify the backplane power. Ensure the load voltage is within 85-264 VAC and the frequency is 47-63 Hz. If an output trips, confirm the continuous current per point does not exceed the derated value at the operating temperature. For persistent faults, consult the Allen-Bradley troubleshooting guide or contact Petro Auto Tech for support.

FAQ about 1746-OA8

Q: What is the maximum continuous current per point on the 1746-OA8?

A: The continuous current per point is 1.00 A at 30 °C (86 °F) and derates to 0.5 A at 60 °C (140 °F).

Q: Can the 1746-OA8 handle 240 VAC loads?

A: Yes, the nominal output voltage is 120/240 VAC, and the output voltage range is 85-264 VAC.

Q: How many output groups does the 1746-OA8 have?

A: It has two groups of four channels each, providing isolation between groups.

Q: What is the backplane current consumption of the 1746-OA8?

A: The module consumes 185 mA from the 5 VDC backplane supply.

Q: What is the surge current rating per point?

A: Each point can handle a surge current of 10 A for 25 ms.

Q: Is the 1746-OA8 compatible with SLC 500 processors?

A: Yes, it is part of the SLC 500 series and works with all SLC 500 processors.

Product Support & Availability

The 1746-OA8 is in stock and ready to ship from Petro Auto Tech. As a trusted supplier of industrial automation parts, Petro Auto Tech offers fast delivery and expert support. Please verify current lifecycle status and availability before ordering.