Allen-Bradley 1746-IA16 AC Input Module SLC 500

Allen-Bradley 1746-IA16 SLC 500 Digital AC Input Module

Product Introduction

The 1746-IA16 is a digital AC input module from the SLC 500 series. It provides sixteen input channels in a single slot. Each channel accepts AC voltages from 85V to 132V AC at 47-63 Hz.

This module connects directly to field devices such as limit switches, push buttons, and proximity sensors. The processor reads these inputs during the input scan phase. Without accurate input signals, the controller cannot execute its logic properly.

Therefore, the 1746-IA16 plays a critical role in any SLC 500 system. It bridges the gap between the physical process and the PLC logic.

Key Technical Specifications

The 1746-IA16 draws only 85 mA from the 5V DC backplane. It consumes no current from the 24V DC backplane. This low power draw leaves plenty of capacity for other modules.

Signal delay is 35 ms maximum for the ON state. OFF state delay reaches 45 ms maximum. These values ensure stable operation in electrically noisy environments.

Off-state voltage maximum is 50V AC. Off-state current is 2 mA maximum. The nominal input current at 120V AC is 12 mA.

Inrush current duration lasts up to 500 microseconds. Maximum inrush current is 0.8 mA. This low inrush protects the module and connected devices.

Terminal and Wiring Details

The 1746-IA16 has twenty terminals. Terminals 18 and 19 serve as internally connected commons. This common connection simplifies wiring for multiple inputs sharing the same neutral.

A removable terminal block makes installation and replacement easy. You can swap the 1746-IA16 without rewiring the field devices. Just remove the terminal block, replace the module, and reattach the block.

Use the 1746-HT and 1746-HCA I/O connection cables for extended wiring needs. Always follow local electrical codes when installing AC input wiring.

Installation Guidelines

Follow these steps to install the 1746-IA16 correctly:

1. Remove power from the SLC 500 chassis.

2. Select an empty slot in the chassis.

3. Slide the 1746-IA16 into the slot until it seats firmly.

4. Secure the module with the top and bottom retaining screws.

5. Attach the removable terminal block.

6. Connect AC input devices to the appropriate terminals.

7. Apply power and verify module operation.

There is no limit on how many 1746-IA16 modules you can install. The only restriction is the number of available slots in your chassis.

Compatibility and System Integration

The 1746-IA16 works with both fixed and modular SLC 500 hardware. It fits local chassis, expansion racks, and remote I/O configurations.

For 200-240V AC applications, use the 1746-IM16 instead. That module is designed for higher voltage ranges.

This module has no internal protection circuitry. Therefore, all connected AC input devices must be compatible with the SLC 500 input circuit inrush current. Using incompatible devices may cause unreliable operation.

Mechanical and Environmental Data

Dimensions are 5 x 2 x 6 inches (13 x 5 x 15 cm). Weight is 0.34 kg (0.75 pounds).

Power dissipation is 0.27 watts per point minimum to 0.425 watts maximum. Total dissipation for all 16 points reaches 4.8 watts.

Operating temperature ranges from 0°C to 60°C. Storage temperature follows standard SLC 500 specifications.

Packaging List

• 1746-IA16 digital AC input module – 1 unit

• Removable terminal block – 1 unit

• Terminal label sheet – 1 unit

Note: No certificates or warranty documents are included in the package.

Shipping Methods

We ship worldwide using FedEx, UPS, or DHL. Tracking information is provided within 24 hours after dispatch.

Frequently Asked Questions (FAQ)

1. Can the 1746-IA16 accept 240V AC signals?
No. The 1746-IA16 only accepts 85-132V AC. For 200-240V AC applications, use the 1746-IM16 module instead.

2. What is the purpose of the removable terminal block?
It allows you to replace the 1746-IA16 without rewiring the field devices. Simply detach the block, swap the module, and reattach it.

3. How many 1746-IA16 modules can I install in one chassis?
You can fill every available slot with 1746-IA16 modules. There is no limit other than physical slot count and backplane power capacity.

4. What happens if the input signal voltage drops below 85V AC?
The module may not detect the input reliably. The off-state voltage maximum is 50V AC, so signals below 85V are considered OFF.

5. Why are the ON and OFF delays different?
The 1746-IA16 has a 35 ms ON delay and a 45 ms OFF delay. This difference helps filter out electrical noise and prevents false triggering in AC systems.