Overview
The Allen-Bradley 1746-OA8 is a discrete AC output module for the SLC 500 series of programmable controllers. This 8-point output module provides current-sourcing outputs arranged in two groups of four channels each, enabling independent control of AC-powered loads. Operating at 85–265VAC with frequencies of 47–63 Hz, the 1746-OA8 occupies a single slot in the 1746 chassis and is ideal for general-purpose 120/240VAC load switching and industrial automation applications.
Key Features
- Eight independent output channels in two groups of four
- Output voltage range: 85–265VAC (47–63 Hz)
- Nominal outputs: 120VAC and 240VAC
- Continuous output current: 1.0A per channel @ 30°C; 0.5A @ 60°C
- Maximum module current: 8.0A @ 30°C; 4.0A @ 60°C
- Fast signal switching: 1ms ON delay, 11ms OFF delay
- Current-sourcing architecture with minimal output voltage drop (1.5V @ 1.0A)
- Backplane current: 185mA @ 5VDC
- NEMA ICS 2-230 noise immunity; UL and CSA certified
- Compact single-slot design; weight 0.4 lbs
Technical Specifications
- Output Voltage Range: 85–265VAC @ 47–63 Hz
- Nominal Outputs: 120VAC, 240VAC
- Number of Channels: 8 discrete outputs
- Output Current (per channel): 1.0A continuous @ 30°C (86°F); 0.5A @ 60°C (140°F)
- Output Current (module total): 8.0A continuous @ 30°C; 4.0A @ 60°C
- Surge Current: 10A for 25ms maximum
- Minimum Load Current: 10mA
- Backplane Current: 185mA @ 5VDC
- Output Voltage Drop (ON state): 1.5V @ 1.0A
- Signal Delay (ON): 1ms resistive load
- Signal Delay (OFF): 11ms resistive load
- Heat Dissipation: 0.925W minimum, 9.0W maximum; 1.0W per point
- Operating Temperature: 0°C to 60°C (32°F to 140°F)
- Vibration Rating: 2.5G @ 57–2000 Hz
- Shock Rating: 30G
- Mounting: Chassis (single slot, 1746 family)
- Enclosure Type: Open style
- Certifications: UL, CSA, NEMA ICS 2-230
- Output Isolation: Comm circuits 500VDC; Backplane 1500VAC
Typical Applications
The 1746-OA8 is suited for industrial control systems requiring reliable AC output switching, including:
- Motor starter and solenoid valve control
- Lighting and HVAC load management
- Pump and compressor ON/OFF control
- Industrial process automation and production line control
- Building automation and facility management systems
- Manufacturing equipment control in food, beverage, and packaging industries
Compatibility & Replacements
Compatible With
- SLC 500 programmable controllers (all models)
- 1746 modular I/O chassis and racks
- RSLogix 500 programming software
- Allen-Bradley automation networks and systems
Replaces / Drop-In Replacement For
- 1746-OA8/A (alternate revision designation)
- Verify compatibility with your system integrator before ordering for specific legacy systems.
Works With
- RSLogix 500 and Studio 5000 engineering software
- Allen-Bradley PLC-5, ControlLogix, and Compact LogixCompactLogix platforms via gateway modules
- Hardwired AC load connections (no communication protocol required)
- Standard industrial control enclosures and distribution panels
