The Allen-Bradley 1746-IA4 is a discrete AC input module engineered for integration within the SLC 500 programmable controller platform. This module provides four isolated input channels designed to interface with 100/120V AC field devices, offering a compact solution for applications requiring low-density AC input monitoring.
Features
Four independent AC input channels.
Compatible with standard 100/120V AC control signals.
Integrated hardware filtering with 35 ms ON and 45 ms OFF signal delays to mitigate noise and contact bounce.
Front-panel LED indicators for real-time status monitoring of each input channel.
Optimized for low-power consumption with minimal backplane current requirements.
Applications
This module is suitable for various industrial automation tasks where AC signal detection is necessary, such as monitoring limit switches, pushbuttons, or auxiliary contacts in control panels. Its small channel count makes it an efficient choice for distributed I/O requirements or small-scale machine control.
Technical Specifications
Brand
Allen-Bradley
Series
SLC 500
Model Number
1746-IA4
Input Channels
4
Voltage Range
85-132V AC
Nominal Current
12 mA at 120V AC
Backplane Current (5V)
35 mA
Operating Temperature
0 to 60 degC (32 to 140 degF)
Max Off-State Voltage
30V AC
Max Off-State Current
2 mA
Installation Guidelines
Ensure the SLC 500 rack power is disconnected before installing or removing the 1746-IA4 module.
Secure the module firmly into the chassis slot and tighten the mounting screws to ensure proper backplane connection.
Use appropriate wire sizing and ensure all field wiring is routed away from high-voltage AC lines to minimize electromagnetic interference (EMI).
Verify that the input voltage does not exceed the specified operating range to prevent module damage.
Maintain adequate ventilation within the cabinet to keep the ambient temperature within the 0 to 60 degC range.
FAQ
What is the primary function of the 1746-IA4?
The 1746-IA4 is a digital input module used to detect the status of 120V AC field devices and convert those signals into logic levels for the SLC 500 processor.
Does this module require 24V DC power?
No, this module does not draw any current from the 24V DC backplane; it only consumes 35 mA from the 5V DC backplane.
Can this module be used for DC input signals?
No, this module is specifically designed for AC signals (47-63 Hz). Using it with DC signals will not provide the intended logic transition and may result in improper operation.
