Introduction to the Allen-Bradley 1746-IA16
Maintenance engineers know that a PLC is only as good as its input interface. The Allen-Bradley 1746-IA16 delivers sixteen discrete AC input channels in a single-slot SLC 500 module. It accepts 85-132V AC signals, making it a direct fit for 100-120V AC control circuits. This module provides the real-time field interface your controller needs to execute logic correctly.

Key Technical Specifications
The 1746-IA16 operates on an 85-132V AC input range at 47-63 Hz. Each channel draws 12 mA nominal at 120V AC. The module consumes 85 mA from the 5V DC backplane. Signal delays are 35 ms ON and 45 ms OFF, with a step response of 100 ms in and 2.5 ms out. The OFF-state voltage maximum is 30V AC, and OFF-state current is 2 mA. Inrush current duration reaches 500 microseconds maximum. The module weighs 0.34 kg and measures 13 cm x 5 cm x 15 cm. It uses 1746-HT and 1746-HCA I/O connections.
Why the 1746-IA16 Belongs in Your Spare Parts Stock
Downtime kills production. When an input module fails, the entire line stops. The 1746-IA16 offers a cost-effective replacement path for SLC 500 systems still running critical processes. Its removable terminal block lets you swap the module without rewiring field terminations. That single feature can cut replacement time from hours to minutes. For maintenance teams, this means faster recovery and lower labor costs.

Applications Across Industries
In automotive assembly, the 1746-IA16 reads limit switches and pushbuttons on conveyor lines. Food processing plants use it to monitor motor starters and safety gates. Water treatment facilities rely on it for pump status and valve position feedback. Each application benefits from the module’s 16 channels per common configuration, which simplifies wiring and troubleshooting.
Installation and Setup
Mount the 1746-IA16 in any available single slot of an SLC 500 chassis. You can install it in fixed or modular hardware, locally or in an expansion rack. The module has twenty terminals, with terminals 18 and 19 serving as internally connected commons. Verify that all AC input devices are compatible with the SLC 500 input circuit inrush current before termination. The removable terminal block allows module replacement without disconnecting field wiring.
Maintenance and Reliability
Inspect terminal connections periodically for tightness and corrosion. Check for proper ventilation around the chassis to prevent heat buildup. The 1746-IA16 has no internal protection circuitry, so ensure field devices do not exceed the 85-132V AC range. Keep spare modules on hand to minimize downtime. Regular input scan verification helps catch failing channels before they stop production.
Compatibility and Integration
The 1746-IA16 integrates directly with SLC 500 controllers, including fixed and modular hardware styles. It works in local or expansion racks. For 200/240V AC operation, the counterpart part number is 1746-IM16. Use 1746-HT or 1746-HCA cables for I/O connections. This module fits any SLC 500 chassis with an available slot.
Selection Guide
Before ordering, verify your chassis has an open slot and your field devices operate within 85-132V AC. Confirm the input signal voltage category matches your application. Check that your controller supports 16-point input modules. SpareTechPLC supplies the 1746-IA16 and can help you confirm compatibility with your existing SLC 500 setup. Please verify current lifecycle status and availability with SpareTechPLC before ordering.
Frequently Asked Questions
What is the voltage range of the 1746-IA16?
The module accepts 85-132V AC input signals at 47-63 Hz.
How many input channels does the 1746-IA16 provide?
It has sixteen input channels with sixteen points per common.
Can I replace the 1746-IA16 without rewiring?
Yes. The removable terminal block allows module replacement without disconnecting field terminations.
What is the backplane current consumption?
The module draws 85 mA from the 5V DC backplane.
What are the signal delay times?
ON delay is 35 ms maximum and OFF delay is 45 ms maximum.