Order now the 1794-OA8I, a rugged 8-channel isolated AC digital output module from the Allen-Bradley FLEX I/O family. Engineered for high-reliability switching, this module provides the individual isolation necessary to safely control AC loads coming from varied power circuits.
What Is the 1794-OA8I?
The 1794-OA8I is a discrete output module that utilizes triac-based switching to control 120V AC loads. It features eight channels that are individually isolated from each other and from the system FlexBus. This architecture is vital for applications where outputs must switch loads powered by different phases or distinct circuit breakers. As part of the modular FLEX I/O system, it snaps onto a terminal base, simplifying the cabinet layout and supporting RIUP (Removal and Insertion Under Power). This allows for rapid maintenance and increased machine uptime in sectors like automotive assembly and food processing.
Key Technical Specifications
- Outputs: 8 individually isolated
- Voltage Range: 74V AC to 132V AC
- Output Current: 1.0A maximum per channel (max 8.0A per module)
- Surge Current: 7A for 45ms
- On-State Voltage Drop: 1.0V AC @ 0.5A
- Off-State Leakage: 2.25mA maximum
- Isolation Voltage: 120V (continuous)
- Power Dissipation: 6.3W @ maximum load
Industrial Compatibility and Protection
The 1794-OA8I is designed to interface with EtherNet/IP, ControlNet, and DeviceNet via the appropriate FLEX I/O adapter. Its isolated design is a primary defense against «cross-talk» between channels. For heavy inductive loads, such as large solenoids or motor contactors, the module’s triac outputs provide a zero-crossing turn-off characteristic that helps reduce electromagnetic interference compared to mechanical relays.
Installation Advice
When installing the 1794-OA8I, it is highly recommended to use the 1794-TBNF fused terminal base. While the module is robust, individual channel fusing on the base provides the ultimate protection against field-side short circuits that could otherwise damage the module’s triacs. Ensure the keyswitch on the base is set to position 2 for proper electronic alignment.
Frequently Asked Questions
Q: Is there a minimum load requirement for the 1794-OA8I?
A: Yes, triac outputs require a minimum load (typically 5mA) to stay in the «On» state. Very small loads like LED indicators may flicker if the load is below this threshold.
Q: Can I use this module for 240V AC loads?
A: No, the 1794-OA8I is rated for 120V AC. For 240V AC applications, you should look for the 1794-OM8 or 1794-OM16 modules.
Do you need more references from this brand? Explore our full catalog of Allen-Bradley here: https://atlantechdrives.com/manufacturers/allen-bradley/
