Allen-Bradley 1746-IV32 SLC 500 Input Module

1746-IV32 32-Channel 24V DC Input Module

Product Introduction

The Allen-Bradley 1746-IV32 is a high-density Discrete Input module for the SLC 500 programmable controller platform. It provides a straightforward method for bringing 24 Volt DC digital signals from field devices—such as proximity sensors, push buttons, and selector switches—into your control system. This module features 32 input points, and it organizes them into four distinct groups of eight channels each to simplify wiring and power distribution. Therefore, this module offers a space-saving and reliable solution for diverse automation projects that require a high channel count.

Technical Specifications

The 1746-IV32 module operates with a nominal input voltage of 24 Volts DC. Its acceptable voltage range is 15 to 30 Volts DC at an ambient temperature of 50 °C. For higher temperature environments up to 60 °C, the range adjusts to 15 to 26.4 Volts DC. The nominal input current per point is 5.1 mA at 24V DC.

For signal timing, the module delivers consistent performance with a maximum ON-state signal delay of 3 ms and a maximum OFF-state signal delay of 8 ms. The minimum ON-state voltage is 15.0 Volts DC, while the maximum OFF-state voltage is 5.0 Volts DC. Additionally, the maximum OFF-state current is 1.5 mA. The 1746-IV32 draws a backplane current of only 0.050 Amperes at 5 Volts DC, which places a minimal load on the chassis power supply.

Mechanical & Environmental Parameters

The Allen-Bradley 1746-IV32 performs reliably in demanding industrial conditions. It features a wide operating temperature range from 0 to +60 °C (+32 to +140 °F) and a storage temperature range between -40 °C and +85 °C (-40 °F to +185 °F). Furthermore, the module operates effectively in environments with 5 to 95% relative humidity, provided there is no condensation.

In terms of mechanical durability, this module withstands a working vibration of 2.5G at 57-200Hz and an operational shock of 30G. It also provides 1500V AC isolation from the backplane for one minute, which enhances overall system safety. The module holds several important agency certifications, including UL, C-UL (Class I, Division 2, Groups A, B, C, D), CE, and C-Tick, which confirm its compliance with international standards.

Installation Guide

Installing the 1746-IV32 is a quick and straightforward process. This single-slot module plugs directly into any available slot within the SLC 500 chassis. First, power off the chassis completely. Next, carefully align the module's circuit board with the card guides inside the chassis, and then slide it firmly into place until it seats fully against the backplane connector.

After physical installation, you can connect your 24V DC field devices. Each group of eight inputs shares a common return terminal. Please note that Series A, B, and C modules include non-replaceable, internally installed fuses per common (rated at 2.5A). However, Series D modules do not have these internal group fuses. Moreover, you can deploy this module in a local I/O rack, an extended rack, or a distributed I/O rack, which offers significant flexibility for various system architectures.

Packaging List

Your shipment of the Allen-Bradley 1746-IV32 will include the following item:

• (1) Allen-Bradley 1746-IV32 SLC 500 Discrete Input Module

The module ships in protective anti-static packaging to ensure it arrives in perfect condition. Standard wiring tools and a suitable 24V DC power supply are necessary for installation, but these items are not included with the module.

All orders ship promptly via FedEx, UPS, or DHL to guarantee fast and dependable delivery.

Frequently Asked Questions (FAQ)

1. What is the key difference between Series A/B/C and Series D of the 1746-IV32?
The main difference lies in the fusing. Specifically, Series A, B, and C modules include non-replaceable 2.5A fuses per input common. In contrast, Series D modules lack these internal fuses and therefore require external circuit protection.

2. Can I use the 1746-IV32 module to read 120V AC signals?
No, you cannot. The Allen-Bradley 1746-IV32 accepts only 24 Volt DC sourcing inputs. Applying AC voltages will damage the module. For AC applications, consider other SLC 500 modules such as the 1746-IA16.

3. Will the 1746-IV32 work with all SLC 500 processors?
Yes, it is fully compatible. The 1746-IV32 works with all SLC 500 processors. It can reside in the local rack with the processor or in remote I/O racks connected via communication networks.

4. What happens if I apply a voltage higher than 30V DC to an input?
Applying a voltage above the maximum specified range can permanently damage the input circuit. Prolonged over-voltage may lead to component failure. Therefore, always verify that your field devices operate within the 15-30V DC range.

5. How can I verify the module is working correctly after installation?
You can check the module's status by observing the input LEDs on its front face. Each of the 32 inputs has a dedicated indicator light. When a valid voltage reaches an input, its corresponding LED will illuminate, which confirms that the signal is arriving correctly.