Product Overview
The Allen-Bradley 1746-OA16 is a Digital AC Output Module from the SLC500 series, manufactured by Rockwell Automation. This module provides sixteen (16) discrete AC output channels arranged in two groups of eight, delivering a nominal output voltage of 120/240 VAC with an operating voltage range of 85-264 VAC. Designed for general-purpose applications, the 1746-OA16 integrates seamlessly into SLC500 programmable logic controllers (PLCs) as local or remote I/O. Its robust design includes filter circuitry and optical coupling for signal noise reduction, ensuring reliable operation in industrial environments.
Technical Specifications Breakdown
Key parameters for the 1746-OA16 are listed below for quick reference:
| Feature | Specification |
|---|---|
| Module Type | Digital AC Output Module |
| Number of Outputs | Sixteen (16) outputs |
| Output Voltage | 120/240 VAC output |
| Operating Voltage Range | 85-264 VAC |
| Output Delay Time, OFF to ON | 11.0 ms |
| Output Delay Time, ON to OFF | 1 ms |
| OFF State Leakage Current | 2 mA |
| Load Current | 10 mA |
| Backplane Current at 5.1 Volts | 0.370 A |
| Continuous Current per Point | 0.50 A @ 30 °C (86 °F) / 0.25 A @ 55 °C (131 °F) |
| Continuous Current per Module, Max | 8.0 A @ 30 °C (86 °F) / 4.0 A @ 60 °C (140 °F) |
| Ambient Operating Temperature | 32 to 140 degrees Fahrenheit |
Industry Applications
From a maintenance engineer's perspective, the 1746-OA16 excels in general-purpose automation tasks requiring reliable AC switching. Typical applications include controlling motor starters, solenoid valves, and indicator lights in manufacturing lines. The module's two output groups allow independent power distribution, simplifying troubleshooting. For example, in a packaging line, one group can handle conveyor controls while the other manages sorting actuators, reducing downtime during maintenance.
Installation & Setup Guidance
Install the module into any single slot of an SLC500 chassis. Ensure the system power supply can deliver the required backplane current of 0.370 A at 5.1 Volts. Use removable terminal blocks for easy wiring—no need to disconnect wires when replacing the module. Verify that the AC supply voltage is within the 85-264 VAC range and frequency is 47-63 Hz. Each output group shares a common, so plan wiring accordingly to avoid cross-load issues.
Maintenance & Reliability
Inspect the module periodically for dust accumulation and ensure ambient temperature stays within 32 to 140 degrees Fahrenheit. The LED indicators on the front panel provide immediate visual feedback of output status, aiding quick diagnostics. Given the 1746-OA16's optical isolation, it withstands electrical noise common in industrial settings. For maximum reliability, operate each output at or below 0.50 A at 30°C and derate to 0.25 A at 55°C.
Compatibility & Integration
The module works with any SLC500 processor as local or remote I/O, and also with CompactLogix and ControlLogix PACs via appropriate communication adapters. It occupies 16-bit I/O memory and one slot. No special configuration software is needed beyond standard ladder logic programming.
Selection Guide & Purchasing Advice
When selecting the 1746-OA16, verify your system's power budget—each module draws 0.370 A from the backplane. For high-temperature environments, account for derating: 8.0 A per module at 30°C drops to 4.0 A at 60°C. SpareTechPLC stocks this module and can confirm current lifecycle status and availability before ordering.
Troubleshooting & Common Issues
If an output fails to energize, check the LED indicator; if off, verify the AC supply voltage at the terminal. For intermittent faults, inspect for loose connections or excessive leakage current (specified at 2 mA OFF-state). Use a multimeter to measure output voltage—should be within 85-264 VAC when active. If multiple outputs in one group fail, the common fuse or power source may be the issue.
