GE UR8NV Analog Input

Configured for current signal acquisition in Universal Relay (UR) series platforms, the GE Multilin UR8NV (UR8NV Analog Input Module) provides direct physical execution of current transformer (CT) signal processing.

Hardware Specifications

Industrial Control and Protection Metrics

• Backplane Bus Communication Velocity: The UR8NV utilizes the UR series high-speed backplane bus to transmit current data to the host relay processor. This interface facilitates deterministic communication, ensuring that fault detection algorithms receive current samples within the required protection window.
• Profinet / EtherNet/IP Deterministic Networks: While this module functions as an analog acquisition node, it integrates into the broader UR protection ecosystem, supporting deterministic network reporting for differential and overcurrent protection schemes via the host relay's communication ports.
• I/O Density Scaling: The 8-channel architecture provides high-density acquisition for CT signals. The module supports both differential and single-ended measurement configurations, allowing for scalable protection logic in generator, transformer, motor, and feeder applications.
• Firmware Flash Compatibility: The module supports field-upgradeable logic and diagnostics integrated with the host relay firmware, ensuring that current sensing calibrations remain compatible with the latest relay software revisions.

Frequently Asked Questions

Q: Does the hot-swappable design apply to the CT input leads?

A: No. While the UR8NV module is physically hot-swappable, the secondary circuits of the current transformers must be externally shorted via a test block before module removal. Extracting the module under load will result in an open-circuited CT, leading to high-voltage generation and potential equipment damage.

Q: Is this module capable of sampling voltage inputs?

A: No. The UR8NV is strictly a current-input module. It does not provide voltage measurement capabilities and must be paired with separate voltage-input modules within the UR chassis for applications requiring combined CT/VT protection logic.

Field Installation Guidelines

• Mechanical Seating: Align the module with the chassis guide rails and slide it into the relay housing until the latch mechanism engages. Firmly press the module to ensure the backplane connectors are fully seated.
• Current Transformer Grounding: Ensure that all CT inputs are properly referenced to the chassis ground bus as defined by the site protection scheme. Proper grounding is necessary to minimize common-mode noise and maintain measurement accuracy.
• Diagnostic Verification: After installation, utilize the GE EnerVista software to verify that the module is correctly recognized by the UR chassis. Perform a loop check to ensure that current readings at the relay match the primary sensor input values.