Product Overview
The Allen-Bradley 1746-OB8 is a digital DC output module from the SLC 500 series, designed for high-current applications. With 8 discrete outputs and a voltage range of 10-50 Volts DC source, this module efficiently drives solenoids, relays, and indicator lights. Its robust construction minimizes downtime, making it a cost-effective choice for industrial automation.
Technical Specifications Breakdown
Key parameters for the 1746-OB8 are listed below for quick reference:
| Feature | Specification |
|---|---|
| Output Type | Digital DC Output Module |
| Number of Outputs | 8 |
| Voltage Range | 10-50 Volts DC Source |
| Current per Output | 1 or 0.5 amps |
| Current per Module | 8 or 4 amps |
| Backplane Current (5 Volts) | 135 milliamps |
| Step Response | 60 milliseconds in, 2.5 milliseconds out |
| Heat Dissipation | 6.9 W total |
Industry Applications
This module excels in high-current environments, such as controlling multiple motor starters or valve banks. By sourcing 1 amp per output at 30°C, it reduces the need for external relays, lowering overall system cost. In packaging lines, its fast step response (2.5 ms out) ensures precise timing, improving throughput.
Installation & Setup Guidance
Mount the 1746-OB8 in any SLC 500 chassis slot. Ensure the backplane current consumption of 135 mA at 5V DC is within your power supply budget. Use twisted-pair wiring for outputs to minimize noise. Always disconnect power before insertion or removal.
Maintenance & Reliability
Inspect the module periodically for dust accumulation. The operating temperature range of 0-60°C and humidity of 5-95% non-condensing ensure reliable operation in typical industrial settings. The electro-optical insulation of 1500 V protects control logic from transient pulses.
Compatibility & Integration
The 1746-OB8 integrates seamlessly with SLC 500 processors and other 1746 I/O modules. Its UL listing and CE compliance simplify system certification, reducing project validation costs.
Selection Guide & Purchasing Advice
When selecting the 1746-OB8, consider the current requirements of your loads. For loads exceeding 1 amp per point, derate to 0.5 amps at 60°C. SpareTechPLC stocks this module with fast shipping. Verify lifecycle status before ordering.
Troubleshooting & Common Issues
If outputs fail to energize, check the external DC supply voltage (10-50V DC) and common connections. Use a multimeter to measure on-state voltage drop (max 1.2V at 1A). Off-state leakage below 1 mA indicates normal operation.
