Overview
The Allen-Bradley 1746-OX8 is an SLC 500 channel to channel isolated relay output module. The 1746-OX8 has 8 isolated high-current relay contact outputs designed for applications requiring separate control paths. It has an operating voltage ranging between 5-125V DC and 5-265V AC, making it suitable for both AC and DC load control in industrial environments.
Key Features
- 8 Individually Isolated Outputs: Each of its 8 relay points is individually isolated, providing improved noise immunity and allowing mixed-voltage load switching without shared commons.
- High-Current Relay Contacts: The 1746-OX8 has a relay contact rating of 30A at 120V AC maximum with a break of 3.0A at 240V AC, and a relay contact rating of 15A with a break of 1.5A. In addition the 1746-OX8 has a relay contact rating of 0.22A and 1.2A at 125V DC and 24V DC respectively.
- Electrical Isolation: The 1746-OX8 offers 1500 V isolation, ensuring reliable separation between field wiring and control logic.
- Industrial Certifications: The module is certified by the UL, CSA, and CE standards.
- Reliable Switching Performance: The 1746-OX8 has a maximum resistive load single delay of 10.0ms when ON and 10.0ms when OFF.
Technical Specifications
- Output Channels: 8 normally open relay contacts
- Output Voltage Range (DC): 5-125V DC
- Output Voltage Range (AC): 5-265V AC
- Backplane Current Consumption: 0.085A at 5V DC and 0.090A at 24V DC
- Heat Dissipation: Approximately 0.825 Watts per point, with a minimum module dissipation of 2.59 Watts and a maximum of 8.60 Watts
- Operating Temperature: 32 to 140 degrees Fahrenheit
- Storage Temperature: -40 to 185 degrees Fahrenheit
- Isolation Voltage: 1500V between I/O and control logic
- Signal Delay: 10 milliseconds maximum resistive load
- Humidity Range: 5 to 95% non-condensing
- Noise Immunity Standard: NEMA ICS 2-230
- Operating Shock Rating: 10 g
Typical Applications
The module features 8 normally open relay contact outputs that are individually isolated, making it ideal for applications requiring separate control paths. The module can control both AC and DC loads and is suitable for interfacing with a wide range of field devices. It is typically used where robust and independent switching is needed, such as in motors, solenoids, or lamps. This makes the 1746-OX8 well-suited for legacy SLC 500 automation systems requiring reliable output control with electrical isolation.
Compatibility & Replacements
Compatible With
- Allen-Bradley SLC 500 programmable logic controllers (PLCs)
- SLC 500 modular chassis platforms
- 1746 series I/O module chassis
- AC and DC field devices requiring isolated relay switching
Replaces / Drop-In Replacement For
The 1746-OX8 Series A is a direct replacement for earlier revisions of the 1746-OX8 output module. The 1746-OX8 is no longer in production and has been officially discontinued by Allen-Bradley (Rockwell Automation). It is considered a legacy product and may only be available through secondary markets or surplus inventories.
Works With
- Allen-Bradley RSLogix 500 programming software
- SLC 500 I/O configuration tools
- Standard PLC rack mounting systems with 40-pin keyed connectors
- Rockwell Automation legacy automation platforms


















