Product Overview
The Allen-Bradley 1746-IA8 is a programmable logic controller module from the SLC 500 I/O modules series. This digital AC input module provides 8 channels for general-purpose input applications, operating on a voltage range of 85-132 Volts AC. It carries the North American Hazardous Location Approval rating, making it suitable for safe operation in certain hazardous environments. The module features a status display and an open-style enclosure, with dimensions of 5" x 2" x 6" (13 cm x 5 cm x 15 cm) and a weight of 0.23 kg.
Technical Specifications Breakdown
Key parameters for the 1746-IA8 are listed below for quick reference:
| Feature | Specification |
|---|---|
| Module Type | Digital AC Input Module |
| Voltage Range | 85-132 Volts AC |
| Inputs | 8 |
| Backplane Current (5 Volts DC) | 50 milliamps |
| Signal Delay | 35 or 45 milliseconds |
| Off State Current | 2 milliamps |
| Slots | 1 |
| Step Response | 100 milliseconds in, 2.5 milliseconds out |
| Operating Temperature | 32 - 140 degrees Fahrenheit |
| Operating Frequency | 47 - 63 Hz |
| Nominal Input Current | 12 mA at 120V AC |
| Thermal Dissipation | 0.27 Watts per point, 0.25 Watts minimum, 2.4 Watts maximum |
| Isolation Voltage | 500V DC (communication circuit), 1500V AC (backplane) |
| I/O Connection | 1746-HT and 1746-HCA |
Industry Applications
The 85-132V AC input range allows direct connection to standard 120V AC sensors and switches without external converters. The hazardous location approval expands deployment options in environments with combustible dust or vapors. When evaluating cost-benefit, this module reduces wiring complexity and lowers installation costs compared to DC-based alternatives in existing AC infrastructure.
Installation & Setup Guidance
Mount the module into a single slot of the SLC 500 chassis. Connect field wiring using the compatible 1746-HT or 1746-HCA I/O connection cables. Ensure the AC supply voltage remains within the 85-132V AC range. The module's status display provides visual indication of input states, aiding during commissioning. Verify that the backplane current draw of 50 mA at 5V DC is within the chassis power supply capacity.
Maintenance & Reliability
Periodically inspect the module for dust accumulation and ensure proper airflow around the enclosure. The operating temperature range of 32 to 140 degrees Fahrenheit supports most industrial environments. The thermal dissipation of 0.27 Watts per point (2.4 Watts maximum) indicates low heat generation, contributing to long-term reliability. No internal user-serviceable components exist; contact AutoDCSTech for replacement if needed.
Compatibility & Integration
It uses the standard backplane interface for communication and power. The module is compatible with a wide range of AC sensors and switches rated for 85-132V AC. The 8 inputs can be grouped for monitoring multiple discrete signals, and the signal delay of 35 ms (ON) and 45 ms (OFF) is suitable for most general-purpose applications.
Selection Guide & Purchasing Advice
When selecting the 1746-IA8, confirm that your application requires 8 AC inputs within the 85-132V AC range and that the hazardous location rating matches your environment. AutoDCSTech offers this module along with compatible accessories like the 1746-HT and 1746-HCA cables. Please verify current lifecycle status and availability with AutoDCSTech before ordering.
Troubleshooting & Common Issues
If inputs do not respond, check the AC supply voltage at the module terminals to ensure it is within 85-132V AC. Verify that the field device (sensor/switch) provides adequate current above the 2 mA off-state threshold. Inspect the I/O connection cables for damage or loose connections. If the status display shows no activity, confirm the backplane power supply is delivering 5V DC and that the module is properly seated in the chassis.
Availability & Condition at AutoDCSTech
| Part Number | 1746-IA8 |
|---|---|
| Availability | In Stock |
| Condition | New |
| Warranty | One Year |
| Origin | US |
