Description

The Allen-Bradley 1756-OA8E is a ControlLogix digital AC output module designed for high-performance industrial automation control systems. This module provides eight (8) isolated output channels, specifically engineered for 120V AC applications. It features integrated electronic fusing, which provides enhanced protection for the output circuitry against overcurrent conditions, reducing the need for external fuses and simplifying maintenance in dense I/O configurations.

Features

• Eight (8) electronically-fused AC output channels.
• Nominal output voltage of 120V AC (operating range 74-132V AC).
• Maximum output current rating of 2 Amps per point at 60 degC.
• Designed for seamless integration into the ControlLogix chassis environment.
• Backplane current draw of 200 mA at 24V DC.
• Continuous isolation voltage rating of 50V.

Applications

The 1756-OA8E is typically utilized in manufacturing and process control environments for driving AC-powered actuators, contactors, solenoids, and motor starters. Its electronic fusing makes it suitable for applications where reliable circuit protection and diagnostic feedback are required within a ControlLogix architecture.

Technical Specifications

Installation Guidelines

• Ensure the ControlLogix chassis is powered down before inserting or removing the module to prevent electrical arcing or damage to the backplane.
• The module should be seated firmly into the chassis slot and secured using the top and bottom latching mechanisms.
• Use appropriate shielded cabling for field wiring to minimize electromagnetic interference (EMI).
• Ensure that the field power supply matches the 120V AC nominal requirement and is properly grounded according to local electrical codes.
• Maintain adequate clearance around the module to allow for proper airflow and cooling within the control cabinet.
• Handle with care to prevent electrostatic discharge (ESD) damage to the internal electronic components.

FAQ

What is the primary advantage of the 1756-OA8E electronic fusing?

The electronic fusing feature provides self-protecting outputs that can detect overcurrent conditions and trip, protecting the module hardware. This eliminates the need for physical external fuses for each point, saving space and reducing downtime during fault recovery.

Is this module compatible with standard ControlLogix chassis?

Yes, the 1756-OA8E is designed to fit into any standard 1756 ControlLogix I/O chassis and is compatible with the standard ControlLogix backplane communication protocols.