GE UR4LA Digital I/O Module

Product Overview

The GE Multilin UR4LA is a versatile and robust Digital I/O Module engineered for the Universal Relay (UR) platform. This module serves as the primary interface between the relay's internal logic and the external substation environment. By integrating 8 optically isolated digital inputs and 4 high-speed Form A outputs, the UR4LA allows for the complex interlocking, alarming, and breaker control necessary for modern power system protection. 

Technical Specifications

• Module Type: Digital Input/Output Module

• Digital Inputs: 8 optically isolated channels

• Input Voltage: Nominal 48 V DC (range 30–60 V DC)

• Input Current: ~5 mA at 48 V DC

• Digital Outputs: 4 Form A (Normally Open) high-speed contacts

• Output Ratings: 250V AC / 220V DC, 8A continuous

• Contact Life: More than 100,000 operations at full load

• Response Time: High-speed (Sub-cycle) for protection schemes

• Design: Hot-swappable, modular UR chassis

Key Features and Engineering Advantages

• High-Speed Output Logic: The 4 Form A outputs are optimized for "high-speed" operation, making them suitable for critical trip circuits where every millisecond counts toward clearing a fault and protecting expensive primary equipment.

• Optically Isolated Inputs: Each of the 8 inputs is optically isolated to provide superior noise immunity. This protects the relay's internal processor from the high-voltage transients and electromagnetic interference common in high-voltage substations.

• Hot-Swappable Reliability: The UR4LA is designed to be removed and replaced while the relay remains powered. This capability is essential for high-availability systems where process interruptions are not an option.

• Robust Switching Capacity: Capable of handling 8A continuous current and up to 250V AC, the output contacts are rugged enough to drive breaker trip coils and heavy-duty auxiliary relays directly.

• Seamless UR Integration: As a standard member of the UR family, this module is automatically recognized by the relay's firmware, simplifying the configuration process within the EnerVista software.