Overview
The Allen-Bradley 1746-OA8 is a discrete AC output module designed for the SLC 500 series programmable logic controllers. This module provides eight (8) output channels organized into two groups of four channels each, with nominal output voltages of 120VAC and 240VAC. Operating across a wide voltage range of 85–265V AC at 47–63 Hz, the 1746-OA8 delivers reliable switching of AC loads in industrial automation and process control applications.
Key Features
- 8 discrete AC output points (2 groups of 4 channels each)
- Wide operating voltage: 85–265V AC @ 47–63 Hz
- Continuous output current: 1.0 A per channel @ 30 °C; 0.50 A @ 60 °C
- Maximum module current: 8.0 A @ 30 °C; 4.0 A @ 60 °C
- Single-slot 1746 chassis mount, open-style enclosure
- LED status indicators for each output channel
- Current-sourcing output architecture
- 1500V AC isolation between field and logic sides
Technical Specifications
- Output Voltage: 85–265V AC
- Output Frequency: 47–63 Hz
- Nominal Voltage Ratings: 120VAC, 240VAC
- Number of Outputs: 8 points
- Output Groups: 2 (4 points per common)
- Continuous Current per Channel: 1.0 A @ 30 °C (86 °F); 0.50 A @ 60 °C (140 °F)
- Maximum Module Current: 8.0 A @ 30 °C; 4.0 A @ 60 °C
- Surge Current: 10 A for 25 ms (per point)
- ON-State Voltage Drop: 1.50V @ 1.0 A
- Signal Delays: ON delay 1 ms; OFF delay 11 ms (resistive load)
- Minimum Load Current: 10 mA per output
- Maximum OFF-State Leakage: 2 mA
- Backplane Current Draw: 185 mA @ 5VDC
- Operating Temperature: 0–60 °C (32–140 °F)
- Storage Temperature: –40–85 °C (–40–185 °F)
- Relative Humidity: 5–95% non-condensing
- Isolation: 1500V AC (field to logic); 500V DC (communications)
- Mounting: Chassis slot, open-style
- Weight: 0.40 lbs
- Certifications: UL, CSA; NEMA ICS 2-230 Noise Immunity
- Vibration Rating: 2.5G @ 57–2000 Hz
- Shock Rating: 30G
Typical Applications
The 1746-OA8 is well-suited for controlling AC loads with low to moderate current requirements. Common applications include:
- Energizing magnetic contactors, solenoids, and AC-rated pilot devices
- Motor starter control and pump switching
- Indicator lamp and alarm circuits
- AC valve and damper actuator control
- Industrial process monitoring and automation systems
- Legacy SLC 500 system retrofits and expansions
Compatibility & Replacements
Compatible With
- SLC 500 programmable logic controllers (all models)
- 1746 I/O chassis (all revisions)
- RSLogix 500 programming software
- 120/240V AC control circuits (pilot duty)
- NEMA-standard industrial AC distribution panels
Replaces / Drop-In Replacement For
- Allen-Bradley 1746-OA8 (all revisions: /A, /B)
- Legacy SLC 500 system output module upgrades
Works With
- RSLogix 500 IDE
- Allen-Bradley SLC 500 series processors
- 1746 backplane and chassis wiring standards
- AC line distribution at 47–63 Hz industrial frequencies
