Allen-Bradley 1746-IM8 SLC 500 Digital AC Input Module 8-Channel

Product Overview

The Allen-Bradley 1746-IM8 is a digital AC input module from the SLC 500 series, manufactured by Rockwell Automation. It provides 8 input channels designed to sense 170-265 Volts AC signals. This module is built for industrial environments requiring durable, field-proven I/O. It is supplied as open-type equipment and intended for use in Pollution Degree 2 environments (per EN/IEC 60664-1) when installed in a suitable enclosure.

Technical Specifications Breakdown

Key parameters for the 1746-IM8 are listed below for quick reference:

Industry Applications

The 1746-IM8 is commonly used in manufacturing lines, material handling, and process control where 200/240V AC discrete signals are present. Its 8-channel density suits applications like motor starter feedback, conveyor presence detection, and valve position sensing. The module's ability to accept general-purpose 125V DC inputs expands its utility in mixed-voltage environments. For cost-conscious operations, this module offers a reliable upgrade path from older 120V AC systems without replacing the entire SLC 500 rack.

Installation and Setup Guidance

Mount the 1746-IM8 in any slot of an SLC 500 chassis. Ensure the backplane connector is fully seated and the locking tab engages. Use the recommended I/O connection cables (1746-HT or 1746-HCA) for field wiring. The module is open-type equipment; install it in an enclosure that meets Pollution Degree 2 requirements. Always disconnect power before inserting or removing the module. Verify the input voltage is within the 170-265V AC range and frequency is 47-63 Hz. The backplane draws 50 mA at 5V DC; confirm the power supply capacity.

Maintenance and Reliability

Inspect the module periodically for signs of overheating, such as discoloration or odor. Keep the enclosure clean and free of conductive dust. The module's operating temperature range of -25 to 60 degrees Celsius allows use in unconditioned plant floors. Relative humidity should stay between 5% and 95% non-condensing. The 30 g operating shock rating ensures resilience in high-vibration applications. No internal adjustments are required; the module is factory-calibrated.

Industry Evolution and the Role of the 1746-IM8

Industrial automation has evolved from simple relay panels to sophisticated programmable logic controllers (PLCs). The Allen-Bradley SLC 500 series, introduced in the 1990s, bridged the gap between legacy hardwired systems and modern modular control. The 1746-IM8 digital AC input module exemplifies this transition, offering reliable 8-channel input sensing for medium-voltage AC signals. Its robust design supports general-purpose 125V DC inputs, making it a versatile choice for retrofit and maintenance projects.

Compatibility and Integration

The 1746-IM8 integrates directly into any SLC 500 chassis and communicates via the backplane. It is compatible with all SLC 500 processors (e.g., 5/01, 5/02, 5/03, 5/04, 5/05). The I/O connection uses 1746-HT or 1746-HCA cables for field termination. No special software configuration is needed; the module is automatically recognized by the processor. For applications requiring 125V DC inputs, the module's voltage range covers this requirement.

Selection Guide and Purchasing Advice

When selecting the 1746-IM8, verify your application's voltage and channel count. For higher channel counts, consider the 1746-IM16 (16 inputs). AutoDCSTech stocks the 1746-IM8 and offers competitive pricing for new and refurbished units. Please verify current lifecycle status and availability with AutoDCSTech before ordering.