PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1794-OA8I FLEX I/O Digital Output Module interfaces industrial controllers with external field actuators. This AC digital output unit provides eight individually isolated output channels for industrial logic execution. The nominal operating voltage is 120 Volts AC across all individual circuits. A yellow status indicator illuminates on the field side when an output is active.
The module mounts into an approved terminal base set to keyswitch Position 8. Total output current capacity is 4.0 Amps, allowing up to 500 milliamperes per channel. Continuous electrical isolation is rated at 120 Volts between channels and from field to backplane. Power dissipation reaches 4.1 Watts at 0.5 Amps and 6.3 Watts at 1.0 Amp. Operating ambient temperatures range from -20 to 55 degrees Celsius.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
|---|
| Product Line | Flex I/O 1794 |
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| UPC | 612598179954 |
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| Weight | 0.56 lbs (0.26 kg) |
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| Outputs | 8 Isolated |
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| Output Voltage nom. | 120V AC |
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| Output Current Rating | 4.0A |
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| On-state Current min. | 5mA per Output |
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| On-state Voltage Drop max. | 1.0V @ 0.5A max. |
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| Off-state Leakage Current max. | 2.25mA |
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| Isolation Voltage | 120V Continuous |
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| Flexbus Current | 80mA @ 5V DC |
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| Power Dissipation | 4.1W @ 0.5A max. |
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| Thermal Dissipation | 14.0 BTU/hr. @ 0.5A max. |
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TECHNICAL INFORMATION
Features
- Provides eight individually isolated 120 Volts AC digital output channels.
- Delivers a total current rating of 4.0 Amps with 500 milliamperes per channel.
- Continuous isolation rating of 120 Volts channel-to-channel and field-to-backplane.
- Dielectric test withstands 1250 Volts AC channel-to-channel for 60 seconds.
- Yellow status indicators show active switching states for each channel.
- Flexbus backplane draw requires 80 milliamperes at 5 Volts DC.
TECHNICAL INFORMATION
Applications
- Connecting actuators triggered by process logic in an industrial automation controller.
- Distributed output control requiring individually isolated 120 Volts AC switching circuits.
TECHNICAL INFORMATION
Connections / Interfaces
- Connect the isolated output to the even-numbered terminal on the base.
- Wire the 120 Volts AC power source to the adjacent odd-numbered terminal.
- Connect individually isolated 120 Volts AC common terminals to each output device.
- Backplane communication connects via the terminal base Flexbus interface.
TECHNICAL INFORMATION
Installation Guidelines
- Set the terminal base mechanical keyswitch to Position 8 before installing the module.
- Align the module over the terminal base and press firmly to secure it.
- Ensure operating surroundings stay between -20 and 55 degrees Celsius.
- Protect circuits using recommended 1.6 Amp, 250 Volts AC slow-blow fuses.
TECHNICAL INFORMATION
Configuration Guidelines
- Confirm keyswitch Position 8 alignment prior to inserting the unit into the base.
- Configure controller output tables to address the eight isolated channels.
- Maintain individual continuous load current at or below 500 milliamperes per point.
TECHNICAL INFORMATION
Compatibility
- 1794-TB2 terminal base
- 1794-TB3 terminal base
- 1794-TB3S terminal base
- 1794-TBN terminal base
- 1794-TBNF terminal base
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELS1794-TB2 terminal base 1794-TB3 terminal base 1794-TB3S terminal base 1794-TBN terminal base 1794-TBNF terminal base
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
Which terminal bases work with the 1794-OA8I module?
The module is compatible with 1794-TB2, 1794-TB3, 1794-TB3S, 1794-TBN, and 1794-TBNF bases. The base keyswitch must be set to Position 8.
What are the output current limits for the 1794-OA8I?
The total module rating is 4.0 Amps. Each individual channel supports a maximum continuous load of 500 milliamperes.
What isolation is provided by the 1794-OA8I output module?
Continuous isolation is 120 Volts channel-to-channel and field-to-backplane. Channel-to-channel withstand is tested at 1250 Volts AC for 60 seconds.
What is the reference price for the 1794-OA8I?
Observed market reference pricing is around $140.00 USD for refurbished units. This is indicative market reference pricing only and is not a final quotation.
