Allen-Bradley 1771-OWNA Relay Output Module

The Allen-Bradley 1771-OWNA Relay Output Module stands as a durable and flexible output solution within the 1771 I/O series, offering dependable relay-based switching for both AC and DC loads. Engineered for industrial automation environments, it provides electrical isolation between field devices and controller logic, ensuring stable and safe operation. This module is particularly valued in systems where mechanical relay output is preferred for handling higher current loads or for compatibility with mixed signal types.

Core Technical Specifications

Application Scenarios

The 1771-OWNA is extensively used in industrial control systems, especially where electromechanical actuation or mixed voltage signal switching is required. Common uses include operating solenoids, relays, indicator lamps, contactors, and motor starters. Because it provides mechanical relay isolation, it is ideal for systems that interface between high and low voltage control components without risk of signal crossover.

Key Advantages

• Broad Compatibility: Supports both AC and DC load switching, reducing the need for multiple module types.

• Reliable Isolation: Mechanical relay contacts ensure electrical isolation between field and control sides.

• Rugged Construction: Built to withstand vibration and electrical noise in harsh environments.

• Flexible Integration: Fully compatible with PLC-5 and the entire 1771 I/O chassis system.

• Field-Proven Longevity: Designed for long operational life even under repetitive load conditions.

FAQs

1. Can the 1771-OWNA handle inductive loads like solenoids or contactors?

   Yes, with proper suppression (flyback diodes for DC, snubbers for AC).

2. Is each output channel isolated from the others?

   Each relay channel is individually isolated, ensuring independent operation.

3. Does it support mixed voltage operation on different channels?

   Yes, each channel can independently switch AC or DC voltages.

4. What is the contact material used in the relays?

   The relays use silver-cadmium oxide contacts for enhanced conductivity and durability.

5. How is relay life affected by load type?

   Resistive loads allow maximum rated cycles; inductive loads reduce mechanical lifespan.

6. Can the module detect output contact failure?

   The module itself doesn’t monitor contact wear, but diagnostics can be implemented at the PLC level.

7. Is there a specific fuse requirement for protection?

   Allen-Bradley recommends external fusing for each output line for overload protection.

8. What are the minimum load requirements per relay?

   Minimum load typically 10 mA at 5 VDC for proper contact reliability.

9. Can the module operate in hazardous environments?

   It’s certified for general industrial use; for hazardous zones, use within approved enclosures.

10. Is relay chattering an issue in high-frequency applications?

    Not recommended for high-frequency switching; solid-state modules are better suited.