Product Overview
When control panels run out of space and every slot counts, the Allen-Bradley 1746-IO12 delivers a practical solution. This SLC 500 Digital I/O Combination Module merges six 120V AC input channels with six relay output channels into a single chassis slot, cutting hardware costs and simplifying wiring. By combining input and output functions, the 1746-IO12 reduces the number of modules needed in an enclosure, freeing up space for other critical components.
The Allen-Bradley 1746-IO12 operates with an input voltage range of 85–132V AC, making it compatible with standard industrial power supplies. Its relay outputs handle both AC and DC loads, offering flexibility across diverse applications. This module is engineered for reliable performance in demanding environments, with CSA certification for Class 1, Division 2 hazardous locations.
Key Features & Benefits
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Six 120V AC inputs – direct connection to sensors, switches, and pushbuttons.
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Six Form A (Normally Open) relay outputs – suitable for controlling contactors, solenoids, and small motors.
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Wide output voltage range – 24–125V DC and 120–240V AC, accommodating mixed-load systems.
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Single-slot design – maximizes chassis capacity in the SLC 500 platform.
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Fast signal response – 35ms ON delay and 45ms OFF delay for efficient process control.
Technical Specifications
| Parameter |
Value |
| Manufacturer |
Rockwell Automation |
| Brand |
Allen-Bradley |
| Part Number |
1746-IO12 |
| Series |
SLC 500 |
| Module Type |
Digital I/O Combination Module |
| Inputs |
Six (6) 120V AC inputs |
| Outputs |
Six (6) Form A Contacts (Normally Open) |
| Input Operating Voltage |
120V AC (range 85–132V AC) |
| Output Operating Voltage |
24–125V DC; 120–240V AC |
| Current per Output (24V DC) |
1.2 A |
| Current per Output (120V AC) |
1.5 A |
| Continuous Current per Module |
8.0 A |
| Backplane Current |
70–90 mA |
| Signal Delay |
35–45 ms |
| Slot Width |
1 |
| Area Classification |
Class 1, Division 2 (CSA certified) |
These specifications are directly sourced from the manufacturer’s data, ensuring accuracy for your system design. The 1746-IO12’s backplane current draw of 0.090A at 5V DC and 0.070A at 24V DC must be considered when calculating total power consumption in a chassis.
Industry Applications
The Allen-Bradley 1746-IO12 excels in applications that require both discrete sensing and load switching in one compact unit. Common use cases include:
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Packaging machinery – monitor limit switches and activate actuators.
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Material handling systems – interface with photoelectric sensors and drive conveyor motor contactors.
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HVAC control panels – manage fan and damper actuators while reading status inputs.
Because the 1746-IO12 combines I/O functions, it is especially valuable in retrofits where panel space is limited. Replacing separate input and output modules with this combination unit can reduce installation time and spare parts inventory.
Installation & Setup Guidance
Installing the Allen-Bradley 1746-IO12 is straightforward. The module occupies one slot in an SLC 500 local or expansion chassis. Follow these steps for a reliable setup:
- Power down the chassis and remove the front cover of the chosen slot.
- Slide the 1746-IO12 into the slot until it seats firmly against the backplane connector.
- Secure the module in place using the locking screws at the top and bottom.
- Wire the input terminals to 120V AC sources and the output terminals to the controlled loads, respecting polarity for DC outputs.
- Apply power and verify the module’s status LEDs indicate normal operation.
Always observe local electrical codes and ensure the module’s power ratings match your load requirements. The 1746-IO12 is designed for Class 1, Division 2 hazardous locations, but proper wiring methods must be followed to maintain that rating.
Maintenance & Reliability
To maximize the lifespan of the Allen-Bradley 1746-IO12, incorporate routine checks into your maintenance schedule. Inspect the module quarterly for signs of overheating, loose wiring, or corrosion. The relay outputs have a finite mechanical life; if a channel fails to switch, replace the module with the same part number—no reconfiguration is needed, but always disconnect power before servicing.
Environmental factors can affect performance. The 1746-IO12 operates reliably in temperatures from 0–60°C and humidity from 5–95% (non-condensing). Avoid exposing the module to chemicals that could degrade its components. Periodic loop validation ensures the I/O points still meet process requirements.
Compatibility & Integration
The Allen-Bradley 1746-IO12 is part of the SLC 500 family, so it integrates seamlessly with SLC 500 processors and other 1746-series modules. You can mix this combination module with discrete, analog, and communication modules in the same chassis, provided you reserve the dedicated processor slot. The module communicates over the backplane, requiring no additional cabling.
For system expansions, place the 1746-IO12 in a local or expansion chassis as needed. Its single-slot footprint leaves ample room for future I/O additions. The module’s relay outputs can drive a wide range of loads, making it a versatile building block for control panels.
Selection Guide & Purchasing Advice
Before purchasing the Allen-Bradley 1746-IO12, verify your system’s voltage requirements and load currents. Confirm that the 120V AC input range and relay output ratings match your application. Also, check your chassis’s backplane current capacity to ensure the total draw of all modules stays within limits.
When you need genuine Allen-Bradley parts, PLC Source PRO offers the 1746-IO12 with fast shipping and professional support. We understand that downtime costs money, so we stock a wide range of SLC 500 modules to keep your operations running.