Allen-Bradley 1746-IO12 SLC 500 Combo I/O Module

1746-IO12 Allen-Bradley 6-Input 6-Relay Output Combo Module

The 1746-IO12 module offers a cost-effective solution for applications requiring both AC inputs and relay outputs. This combination module belongs to the SLC 500 family and occupies just one chassis slot. Specifically, it provides six 120VAC input channels and six Form A (Normally Open) relay contact outputs. Therefore, it eliminates the need for separate input and output modules in smaller systems. Additionally, its compact footprint saves valuable panel space and reduces overall system costs.

Input Specifications and Operating Range

The input section of the 1746-IO12 accepts AC voltage signals from field devices. It operates with a nominal voltage of 120VAC and accepts a range from 85 to 132VAC at 47 to 63Hz. This input functionality mirrors that of the 1746-IA16 module, though with fewer channels. Each input point dissipates 0.27 watts, contributing to the module's total heat load. The input signal delay measures 35 milliseconds for the ON transition and 45 milliseconds for the OFF transition. This predictable response ensures reliable detection of field device states in most industrial applications.

Output Specifications and Relay Contact Ratings

The output section provides six Form A relay contacts for controlling external loads. These normally-open contacts support both AC and DC load types. Specifically, each output handles 1.5 amps at 120VAC and 1.2 amps at 24VDC. The continuous current per module reaches 8.0 amps total across all outputs. Moreover, each contact carries a maximum output power rating of 28VA. The relay outputs work with voltage ranges from 5 to 265VAC at 47 to 63Hz and from 5 to 125VDC. Each output point dissipates 0.133 watts maximum, while the module's total heat dissipation reaches 4.60 watts.

Backplane Current Draw and Power Considerations

This combination module draws 90mA from the 5VDC backplane and 70mA from the 24VDC backplane. These values remain consistent across normal operating conditions. The module's total power consumption reflects its mixed input and output design. For proper operation, ensure your power supply can handle these additional current requirements. Furthermore, consider the aggregate heat dissipation of 4.60 watts when planning cabinet cooling and ventilation.

Hazardous Location Certification and Safety Features

The Allen-Bradley 1746-IO12 holds CSA certification for Class 1, Division 2 hazardous locations. This approval permits installation in areas where flammable gases or vapors may occasionally be present. The module provides electro-optical isolation tested at 1500V between the I/O terminals and the control logic. This isolation protects the processor from voltage spikes and ground loop issues. Additionally, it meets NEMA standard ICS 2-230 for noise immunity, ensuring reliable operation in electrically noisy industrial environments.

Mechanical and Environmental Specifications

This module operates reliably across a functional temperature range of 0°C to 60°C (32°F to 140°F). It handles storage temperatures from -40°C to 85°C (-40°F to 185°F). The humidity tolerance ranges from 5% to 95% non-condensing for versatile deployment. Moreover, the 1746-IO12 withstands operational vibration of 2.5G at 57 to 200 Hertz. Its shock rating reaches 30G, making it suitable for locations with mechanical stress from nearby equipment.

Installation Guidelines and Chassis Placement

Install this module in any available slot of the SLC 500 chassis except slot 1, which the processor occupies. The single-slot design simplifies integration into new and existing systems. You can mix it freely with other SLC 500 modules in local or expansion chassis. For remote installations, it works through a communication adapter. Always disconnect power before installing or removing the module, as it does not support RIUP. Regular maintenance and loop validation help ensure optimal operation over time. If performance degrades significantly, replace the module with the same part number without reconfiguration, but only after removing supply power.

Packaging and Shipping Information

• One 1746-IO12 digital I/O combination module

• One removable terminal block for field wiring

• One installation instruction sheet

• Anti-static protective packaging

All orders ship via FedEx, UPS, or DHL with tracking numbers provided. Inspect all items upon delivery and report any transit damage immediately.

Frequently Asked Questions

1. Can the 1746-IO12 outputs switch DC loads directly?
Yes, the relay outputs handle both AC and DC loads. Each output supports up to 1.2 amps at 24VDC, making them suitable for small DC solenoids and indicator lights.

2. What is the difference between the 1746-IO12 and the 1746-IA16?
The 1746-IO12 combines 6 AC inputs with 6 relay outputs in one module. The 1746-IA16 offers 16 AC inputs only and no output capability. Choose based on your I/O count requirements.

3. How does temperature affect the input voltage range?
The input voltage range remains at 85-132VAC across the full operating temperature range of 0°C to 60°C. No derating applies for temperature within this range.

4. Can I install the 1746-IO12 in a remote I/O chassis?
Yes, this module works in remote I/O chassis when connected through a compatible communication adapter. It functions identically to local chassis installation.

5. What happens if I exceed the 8.0A total continuous current?
Exceeding the 8.0A total continuous current per module can cause overheating and permanent damage. Always distribute loads across outputs and stay within the specified limit.