The 1794-OA8 from Allen-Bradley provides a robust AC output solution. This module controls eight non-isolated outputs for industrial automation tasks. It directly integrates into the flexible Flex I/O platform. Its design prioritizes reliable switching and efficient system diagnostics. Engineers use it to drive various 120V AC field devices. This module helps reduce system start-up time significantly. It also simplifies finding and fixing wiring or power faults.
Product Procurement & Buyer Guide
The 1794-OA8 operates on a nominal 120V AC supply voltage. Its output voltage range spans from 85 to 132 Volts AC. This flexibility ensures stable operation even with power fluctuations. The module supports a total output current rating of 4 Amps. Each of the eight outputs can handle 500 mA at 55°C. This current capacity suits a wide range of solenoid and relay loads. The module offers a minimum on-state current of 5 mA per output. This low threshold allows it to switch sensitive loads reliably.
You must select the correct terminal base unit for installation. The 1794-OA8 mounts directly onto several base units. Compatible bases include the 1794-TBN, 1794-TB3, and 1794-TB2 models. The 1794-TB3 terminal base provides three screw clamp terminal strips. It supports daisy-chaining for power distribution across modules. This base handles up to 10 Amperes of supply current. It draws 640 mA from the 5V DC backplane. This combination ensures a secure and organized wiring infrastructure.
The module includes built-in diagnostic capabilities for field devices. It checks the health of connected I/O and wiring continuously. This feature drastically cuts down the time spent on troubleshooting. It allows maintenance teams to identify problems quickly and accurately. The module also monitors the power supply for anomalies. This proactive monitoring prevents unexpected system shutdowns and failures. It enhances overall system reliability in demanding industrial environments.
Step-by-Step User & Installation Guide
First, ensure the system power is completely turned off. Mount the chosen terminal base onto a standard DIN rail. Hook the base over the top of the rail and push down. The locking mechanism will secure it firmly in place. Slide the terminal base tightly against the adjacent adapter module. This action engages the FlexBus connector for communication.
Next, wire the field devices to the top terminal strip of the base. Use the appropriate wire size between 22 and 12 gauge. The top strip contains 16 terminals for I/O signal connections. Connect the AC common wires to the middle terminal strip. The bottom terminal strip receives the AC voltage supply wires. Torque the screw clamps to between 0.56 and 0.79 Nm. This ensures a gas-tight connection that resists vibration.
Now, align the 1794-OA8 module with the terminal base keyway. Gently press the module into the base until it clicks. The module draws only 80 mA from the 5V DC FlexBus. Its maximum power dissipation is 4.1 Watts at 0.5 Amps. The thermal dissipation reaches 14 BTU per hour at that load. Ensure adequate airflow around the module for cooling. The module operates reliably in non-hazardous and Class 1, Division 2 areas.
Finally, verify all wiring against the module’s schematic diagram. Apply power and check the module’s status indicators. The output signal delay is a maximum of 1/2 AC cycle. This applies for both the ON-to-OFF and OFF-to-ON transitions. The module can handle a surge current of 7 Amps for 40 milliseconds. This surge is repeatable every 8 seconds for demanding loads. The off-state leakage current is a maximum of 2.25 mA. This low leakage prevents unwanted activation of sensitive loads.
Logistics & Standard Packaging Details
- One (1) Allen-Bradley 1794-OA8 Flex I/O Output Module
- Manufacturer: Rockwell Automation
- Brand: Allen-Bradley
- UPC: 10612598137845
- Express delivery is available via FedEx, UPS, and DHL.
