Description
GE UR8NH
Technical Specifications:
- Series: GE Multilin UR (Universal Relay)
- Module Type: CT/VT module
- Configuration: Standard 8CT with enhanced diagnostics
- CT Ratings: 1 A and 5 A
- Maximum Analog Signals: Up to 24 signals (across module variants) for AC power line monitoring
- Mounting: Plug-in module inside UR relay chassis
- Firmware Compatibility: New CT/VT module (UR8NH is a newer model) requires firmware version 4.0x or higher with a new CPU
Functional Features:
- Provides standard 8CT inputs for current monitoring
- Enhanced diagnostics capability verifies analog signal integrity
- Up to 24 analog signals for comprehensive AC power line monitoring
- Supports 1 A and 5 A CT ratings for flexible application
- Integrates with UR relay standardized health diagnostics for continuous self-monitoring
- Health diagnostics perform hardware assessment at startup and continuously during operation
- Monitors CT/VT input circuits and components for early fault detection
- Some CT/VT module variants offer sensitive ground fault protection (8G, 8J, 8M, 8R series)
Application Scenarios:
- Substation protection relays requiring multiple CT inputs for overcurrent and differential protection
- Transformer protection with multiple winding CT monitoring
- Busbar and breaker failure protection
- Generator protection with phase and ground CT monitoring
- Industrial power distribution protection requiring 8 CT inputs
Performance Parameters:
- Standard 8CT configuration for comprehensive current monitoring
- Enhanced diagnostics verify signal integrity for reliable protection
- Compatible with 1 A and 5 A CT secondary ratings
- Up to 24 analog signals for AC power line monitoring (across module variants)
- Continuous health diagnostics for proactive maintenance
Material and Structural Characteristics:
- Industrial-grade PCB with precision CT input transformers
- Plug-in module form factor matching UR relay chassis
- Front-panel accessible through hinged relay front cover
- Robust construction for substation and industrial environments
- Rear terminal blocks for CT input wiring
Working Principle: The module receives current signals from up to eight CTs, scales them to levels the relay electronics can process, and digitizes them for transmission to the UR relay CPU. The enhanced diagnostics use advanced algorithms to verify analog signal integrity, detecting open circuits, short circuits, or signal corruption. The CPU uses the current data for protection functions (overcurrent, differential, ground fault) and metering. Health diagnostics continuously monitor the CT input circuits and components, reporting faults via the front-panel LCD or EnerVista UR software for proactive maintenance. Installation Requirements:
- Open the hinged front panel of the UR relay to access the module rack
- Insert the UR8NH module into the designated slot
- Connect up to eight CT inputs to the rear terminal blocks per schematics
- Configure CT ratios using EnerVista UR software
- Verify firmware version 4.0x or higher is loaded with a compatible new CPU
Usage Notes:
- As a newer CT/VT module, pair UR8NH with a new CPU to avoid hardware mismatch errors
- Ensure firmware version 4.0x or higher is installed for compatibility
- Verify CT ratio settings match the installed current transformers
- Use EnerVista UR software to monitor diagnostic status and signal integrity
- Periodically verify measurement accuracy using a relay test set
- Replace only with an identical UR8NH module to maintain configuration integrity
