Product Overview

The Allen-Bradley 1746-IO8 is a digital I/O combination module for the SLC 500 system. This module provides four AC inputs and four relay outputs in a single unit. It operates in standard industrial environments and hazardous locations. The Allen-Bradley 1746-IO8 fits in any slot except slot 0 of the 1746 I/O chassis. Users trust this module for flexible combination I/O applications.

Technical Specifications

The 1746-IO8 delivers reliable digital I/O with hazardous location certification. Below are the complete technical details.

General Specifications

• Manufacturer: Rockwell Automation for industrial control reliability.

• Brand: Allen-Bradley for SLC 500 compatibility.

• Part Number: 1746-IO8 for precise identification.

• Series: SLC 500 programmable controller family.

• Module Type: Digital I/O Combination Module.

• UPC: 10662073902697 for universal product identification.

• Chassis Location: Any I/O slot except slot 0.

• Applications: Combination 120 Volts AC I/O.

Input Specifications

• Number of Inputs: 4 inputs per module.

• Input Voltage: 120V AC.

• Operating Voltage Range: 85-132 Volts AC.

• Input Signal Delay: 35-45 milliseconds.

• Outputs per Common: 4 points per common (relay outputs).

• Input Points: Four AC input channels.

Output Specifications

• Number of Outputs: 4 relay contact outputs.

• Output Type: Normally Open (N.O.) contact.

• Output Rating (AC): 5-65V AC at 47-53 Hz.

• Output Rating (DC): 5-125V DC.

• Output Signal Delay: 35-45 milliseconds.

• Current per Output (120 VAC): 1.5 Amps continuous.

• Current per Output (24 VDC): 1.2 Amps continuous.

• Relay Configuration: 4 points per common.

Backplane Power and Heat Dissipation

• Backplane Current at 5V DC: 0.03A (30 milliamps).

• Backplane Current at 24V DC: 0.025A (25 milliamps).

• Heat Dissipation per Input Point: 0.27W.

• Heat Dissipation per Output Point: 0.133W.

• Aggregate Heat Dissipation: 3W total.

Hazardous Location Certification

• Class 1, Division 2: Groups A, B, C, and D rated.

• Non-Hazardous Operation: Standard industrial environments.

• Certifications: CE, CSA, and C-UL certified.

• Noise Immunity: Meets NEMA standard ICS 2-230 rated.

Environmental Specifications

• Operating Temperature: 0 to 60°C (32 to 140°F).

• Non-Operating Temperature: -40 to 85°C (-40 to 185°F).

• Operating Humidity: 5 to 95% non-condensing.

• Operational Shock Rating: 30G.

• Operational Vibration: 2.5G at 57-200Hz.

Installation Guide

Follow these steps to install the Allen-Bradley 1746-IO8 correctly.

1. Power Down the Chassis: Turn off all power to the SLC 500 rack.

2. Verify Power Supply Capacity: Ensure backplane can supply 0.03A at 5V and 0.025A at 24V.

3. Locate an Available Slot: Find any I/O slot except slot 0.

4. Insert the Module: Slide the 1746-IO8 into the slot carefully.

5. Secure the Module: Lock using the retaining clips at top and bottom.

6. Wire AC Inputs: Connect 85-132V AC signals to the four input channels.

7. Wire Relay Outputs: Connect loads to the four N.O. relay contacts.

8. Check Output Current: Do not exceed 1.5A at 120V AC or 1.2A at 24V DC.

9. Verify Common Wiring: Note outputs are 4 points per common.

10. Apply Power: Turn on the backplane power to the chassis.

11. Check Signal Delay: Verify 35-45 ms delay for input and output states.

12. Test Inputs: Apply AC signals and monitor input status.

13. Test Outputs: Energize relays and verify contact closure.

14. Monitor Heat Dissipation: Ensure aggregate heat stays below 3W.

Installation Notes

• The module fits any slot except slot 0 of the 1746 I/O chassis.

• Hazardous location rating includes Class 1, Division 2, Groups A, B, C, D.

• Outputs are relay contacts with N.O. configuration.

• Signal delay is 35-45 ms for both ON and OFF states.

• The module has CE, CSA, and C-UL certifications.

Packaging List

This unit ships as a new and original product.

• Allen-Bradley 1746-IO8 Digital I/O Combination Module

• Product data sheet with wiring diagram

• Hazardous location certification document

• Anti-static factory packaging bag

Frequently Asked Questions (FAQ)

1. How many inputs and outputs does the 1746-IO8 provide?
The Allen-Bradley 1746-IO8 provides 4 AC inputs and 4 relay outputs in a single module. Outputs are 4 points per common.

2. What is the operating voltage range for the inputs on this module?
The 1746-IO8 inputs operate at 85-132 Volts AC. This matches most SLC 500 combined I/O modules.

3. What is the current rating per output on the 1746-IO8?
Each output on the Allen-Bradley 1746-IO8 handles 1.5 Amps at 120V AC or 1.2 Amps at 24V DC. Outputs are normally open relay contacts.

4. Is the 1746-IO8 certified for hazardous locations?
Yes, the 1746-IO8 is rated for Class 1, Division 2, Groups A, B, C, and D hazardous industrial environments. It also works in non-hazardous areas.

5. What is the signal delay time for this combination I/O module?
The Allen-Bradley 1746-IO8 has a signal delay of 35-45 milliseconds for both input and output ON and OFF states.