Description

Brief Product Description

The Allen-Bradley 1756-OA8E is a high-performance ControlLogix discrete output module featuring eight electronically fused channels for 120V AC applications. It provides robust circuit protection and rapid switching capabilities to manage industrial actuators, motor starters, and solenoid valves.

Advanced Discrete Control and Load Management

The Allen-Bradley 1756-OA8E serves as a critical interface within the ControlLogix platform, specifically engineered to switch AC loads with high precision. This module provides eight independent output channels organized into two isolated groups of four. It operates across a broad voltage range of 74V to 132V AC, making it highly adaptable to various industrial power conditions. By delivering up to 2 A per channel at 60°C, the module effectively manages high-demand peripheral devices. Consequently, process engineers utilize the 1756-OA8E to drive solenoids and contactors where reliable AC switching is essential for automated sequence execution.

Superior Circuit Protection and Thermal Efficiency

Safety and hardware longevity define the architecture of the 1756-OA8E module. Unlike standard output cards, this unit features integrated electronic fusing for every output point, which eliminates the need for external fuses and reduces cabinet space requirements. This proactive protection layer safeguards the module against overcurrent conditions and short circuits in the field. Furthermore, the module maintains excellent thermal performance with a dissipation rating of only 18.76 BTU/hr. This efficiency ensures that the ControlLogix chassis remains within safe operating temperatures even during high-density I/O operations. Transitioning to electronically fused modules significantly lowers maintenance overhead by providing resetable protection and clear fault diagnostics.

High-Speed Switching and Industrial Compatibility

Performance speed is a standout characteristic of the 1756-OA8E, as it achieves transition times as fast as 9.3 ms at 60 Hz. This rapid responsiveness allows for tighter control loops and more accurate timing in high-speed manufacturing environments. The module also handles significant inrush currents, supporting surges up to 20 A for short durations, which is vital when starting inductive AC loads. For secure field wiring, the unit is compatible with 1756-TBNH or 1756-TBSH Removable Terminal Blocks (RTB). Although Rockwell Automation officially moved this product to a discontinued status in December 2012, it remains a gold standard for reliability in existing ControlLogix installations worldwide.

Key Technical Characteristics

• 8-Channel AC Density: Provides compact control for multiple AC devices within a single chassis slot.
• Electronic Fusing: Offers individual channel protection to prevent system-wide downtime during field faults.
• High Surge Capacity: Withstands up to 20 A inrush current for 43 ms to handle inductive motor starter loads.
• Group Isolation: Features two isolated groups of four channels to enhance signal separation and safety.
• Rapid Signal Transition: Ensures fast logic execution with sub-11ms switching speeds.
• Broad Environmental Range: Operates consistently in temperatures ranging from 0°C to 60°C.

Technical Specifications