Description
Hard-Numbers: Technical Specifications
- CT Inputs: 4 channels (3 phase + 1 ground), 1A/5A configurable
- VT Inputs: 4 channels, up to 300VAC line-line
- Accuracy: Voltage ±0.5% FS; Current ±1% FS
- Frequency: 45–65Hz (50/60Hz nominal)
- Isolation Rating: 2500Vrms between CT/VT and backplane
- Operating Temperature: -40°C to +70°C continuous
- Power Draw: 6.5W max, backplane-powered
- Hot Swap: Live insertion/removal for in-service maintenance
- Termination: Spring-clamp, 14–22 AWG
- Burden: CT 0.05VA; VT 0.5VA
GE UR-8FV
The Real-World Problem It Solves
Raw CT/VT outputs are high-energy and noisy. Unscaled signals damage relay inputs, cause metering errors, and trigger false trips in substations.
Where you’ll typically find it:
- Transmission substations (110–220kV) for feeder/transformer protection
- Power plant generator and auxiliary transformer racks
- Industrial refineries and steel mills with high-current loads
Bottom line: It safely isolates and scales high-voltage CT/VT signals, ensuring accurate metering and reliable protection.
Hardware Architecture & Under-the-Hood Logic
UR-8FV uses per-channel isolated analog front-ends (AFE), independent of the main relay CPU. All CT/VT circuits have reinforced galvanic isolation.
- CT (1/5A) and VT inputs feed to isolated AFE stages.
- Precision burden resistors and op-amps scale signals to 0–5V logic levels.
- 16-bit ADCs convert analog signals to digital samples.
- Digital data crosses the isolated backplane to the host relay CPU.
- Onboard diagnostics monitor range, saturation, and wiring faults.
Field Service Pitfalls: What Rookies Get Wrong
CT Burden MismatchTechs mix 1A/5A CT taps without reconfiguring the module. Mismatched burden causes saturation and inaccurate readings.
- Field Rule: Match module CT setting (1A/5A) to physical CT tap; verify via EnerVista before energizing.
VT Secondary Grounding ErrorsMissing or poor VT ground connections introduce noise. Unstable voltages cause nuisance trips.
- Quick Fix: Torque terminals to 0.8–1.0Nm; bond VT secondary grounds to station ground bus.
Overloading VT CircuitsAdding extra meters/recorders to VT terminals exceeds burden. Voltage distortion degrades protection accuracy.
- Field Rule: Limit VT secondary load to <50VA; use dedicated VT distribution blocks.
GE UR-8FV
Commercial Availability & Pricing Note
Please note: The listed price is for reference only and is not binding. Final pricing and terms are subject to negotiation based on current market conditions and availability.
