Allen-Bradley SLC 500 8-Point AC Output Module 1746-OA8

Product Overview

The Allen-Bradley 1746-OA8 is an 8-point discrete AC output module engineered for the SLC 500 modular control system by Rockwell Automation. Designed for controlling AC-powered loads such as solenoids, motor starters, relays, and indicator lamps, this module operates across a nominal 120/240 V AC supply voltage with a broad operating range of 85 to 264 V AC (47–63 Hz).

Organized into two (2) individually isolated groups of four (4) output channels each, the 1746-OA8 delivers reliable signal isolation and surge protection for industrial automation systems. Weighing approximately 0.35 kg (0.77 lbs), it installs into any single slot of an SLC 500 chassis, drawing a low 185 mA at 5 V DC from the backplane power supply.

Core Technical Advantages

• Dual Grouped Channel Architecture: Features 8 AC output channels divided into two isolated groups of 4 points, enabling independent voltage source control per bank.
• High Current Output Performance: Provides up to 1.0 A per point at 30°C, offering higher power output per channel compared to high-density modules.
• Robust Surge Capability: Supports inrush surge currents up to 10 A per point for 25 ms, allowing safe switching of heavy inductive loads.
• Optical Noise Isolation & Status LEDs: Integrates optical coupling between backplane logic and field circuitry, complete with front-panel status LEDs for real-time channel diagnostics.

Technical Specifications

Installation & Handling Guidelines

• Chassis Power Isolation: Always turn off power to the SLC 500 rack prior to inserting or removing the 1746-OA8 module to avoid damaging backplane connections.
• Thermal Considerations: Observe temperature derating rules, limiting individual point currents to 0.50 A if operating temperatures reach 60°C (140°F).
• Wiring Isolation: Route AC output field wiring separately from low-voltage DC signals and sensor wiring to minimize noise coupling within control enclosures.

Technical FAQs

Q1: What is the continuous current rating per point for the Allen-Bradley 1746-OA8 module?
A1: It supports 1.0 A per point at 30°C, derating to 0.5 A per point at 60°C.

Q2: How much backplane current does the 1746-OA8 module consume?
A2: The module consumes 185 mA at 5 V DC from the chassis backplane power supply.

Q3: How are the output points grouped on the 1746-OA8 module?
A3: The 8 output channels are organized into two isolated groups of 4 channels each.