Overview
The Allen-Bradley 1746-OX8 Series A is a digital contact output module designed for the SLC 500 family of programmable logic controllers. This 1746-OX8 module features 8 individually-isolated high-current relay contact outputs suitable for controlling motors, solenoids, contactors, pilot lights, and other heavy-duty field devices. Each relay point is independently isolated, enabling mixed-voltage load switching without shared commons and superior noise immunity in harsh industrial environments.
Key Features
- 8 Isolated Relay Outputs — each point individually isolated for independent control paths and mixed-voltage applications
- High-Current Switching — 30 A make/break at 120 VAC, 1.2 A at 24 VDC; continuous rated 3 A at 120 VAC, 1.2 A at 24 VDC
- Wide Operating Voltage Range — 5–265 VAC (50/60 Hz) or 5–125 VDC for flexible field-device interfacing
- 1500 V Optical Isolation — electro-optical isolation between field wiring and control logic; surge suppression built-in
- Status Indicators — per-point LED status for quick troubleshooting and diagnostics
- Compact Chassis Mounting — open-type enclosure, hot-swap removal allowed when backplane power is off
Technical Specifications
- Output Type: Isolated normally open (N.O.) relay contacts
- Number of Outputs: 8 points
- Output Voltage (AC): 5–265 VAC, 50/60 Hz
- Output Voltage (DC): 5–125 VDC
- Max Make Current (120 VAC): 30 A
- Max Break Current (120 VAC): 30 A
- Max Make Current (240 VAC): 15 A
- Max Break Current (240 VAC): 1.5 A
- Continuous Current (5 A at 120 VAC): 3600 VA make / 360 VA break
- DC Max Make/Break (125 VDC): 0.22 A
- DC Make/Break (24 VDC): 1.2 A each
- Continuous DC (125 VDC): 1 A @ 28 VA make/break
- Continuous DC (24 VDC): 2 A @ 28 VA make/break
- Signal Delay: max 10 ms ON, 10 ms OFF (resistive load)
- Optical Isolation: 1500 V between I/O terminals and control logic
- Backplane Current: 85 mA at 5 VDC; 90 mA at 24 VAC
- Heat Dissipation (per point): 0.825 W energized; total module 8.6 W all outputs ON
- Operating Temperature: 0–60 °C (32–140 °F)
- Storage Temperature: −40–85 °C (−40–185 °F)
- Operating Humidity: 5–95% non-condensing
- Operating Vibration: 0.015 in. displacement at 5–57 Hz
- Operating Shock: 10 g
- Noise Immunity: NEMA ICS 2-230 compliant
- Certifications: UL, CSA, CE
- Series: A
- Mounting: Horizontal or vertical chassis slot
Typical Applications
The 1746-OX8 is ideal for industrial automation systems requiring isolated, high-current relay-based output control:
- Motor starter and contactor control
- Solenoid and pilot light switching
- Conveyor belt and material-handling equipment control
- HVAC control systems
- Assembly line automation and interlocking
- Process control requiring separate control paths (multi-voltage loads)
- Hazardous and non-hazardous location deployment
Compatibility & Replacements
Compatible With
- Allen-Bradley SLC 500 fixed processors (SLC 5/01, 5/02, 5/03, 5/04, 5/05)
- SLC 500 modular rack and chassis configurations (1746 slot I/O chassis)
- Allen-Bradley I/O racks (1746-A4, 1746 I/O expanders)
- RSLogix 500 programming software
- Standard SLC 500 backplane communication
Replaces / Drop-In Replacement For
The 1746-OX8 Series A is a direct replacement for earlier versions of the 1746-OX8 module. Verify compatibility with your system integrator before ordering for legacy system integration.
Works With
- RSLogix 500 — complete I/O configuration and diagnostics
- Allen-Bradley PanelView HMI systems — synchronized real-time output status
- SLC 500 Instruction Set — output control via standard OTE, MOV instructions
- Native SLC 500 Backplane — direct 1746 chassis slot integration (no external networking)
