Description
GE UR8FV is a CT/VT (current and voltage transformer) input module for the GE Multilin UR protection relay family, used to bring precise primary current and voltage signals into a UR relay for measurement, metering, and protection. It is installed as a plug‑in module inside a UR relay chassis and provides the analog interface between field CTs/VTs and the relay’s digital processor.
GE UR8FV
Product description and parameters
GE UR8FV is typically described as a “CT/VT module” or “relay CT/VT module” for the Multilin UR series. In a standard configuration it offers:
- CT inputs
- Three phase CT inputs for line currents.
- One ground or residual CT input.
- Each input selectable for 1 A or 5 A nominal current (depending on relay configuration and wiring).
- VT inputs
- One multi‑terminal VT input for three‑phase or phase‑to‑neutral voltages, depending on connection.
- Nominal VT secondary voltage in the common protection ranges (for example 100 V or 120 V class, other ranges possible depending on the connected transformer).
- Measurement characteristics
- Frequency range suitable for power systems (around 45–65 Hz).
- Accuracy adequate for protection and metering class measurements, with low CT/VT burden so as not to overload instrument transformers.
- Power and form factor
- Powered internally from the UR relay’s chassis power supply; it does not require a separate auxiliary supply.
- Plug‑in module format, installed in the appropriate UR chassis slot.
- Dimensions and weight consistent with other Multilin UR modules, making it mechanically interchangeable within the series.
In a UR relay, the UR8FV module is responsible for converting high‑accuracy CT and VT secondary currents and voltages into internal analog signals which are then digitized for use by the relay CPU.
Datasheet‑style overview
A datasheet for GE UR8FV normally includes:
- Input ratings
- CT nominal currents: 1 A and 5 A.
- VT nominal voltages: typical protection secondary levels, such as 100 V / 120 V.
- Thermal and short‑time withstand for CT circuits in line with CT secondary performance.
- Frequency and accuracy
- Operating power frequency band around 50/60 Hz.
- Measurement error limits for current and voltage, suitable for protection applications.
- Burden
- Very low VA burden per CT input and per VT input to minimize loading of the instrument transformers.
- Insulation and safety
- Insulation level and impulse withstand suitable for relay‑class equipment.
- Clearances and creepage distances designed for installation inside a UR relay chassis.
- Environmental
- Operating temperature range appropriate for substation and control room environments (spanning typical negative and positive ambient temperatures).
- Storage temperature and humidity limits, and vibration/shock endurance to standard industrial levels.
- Mechanical
- Module height/width/depth to fit the UR rack.
- Plug‑in edge connector and front handle for insertion/removal.
Together, these define the UR8FV as the analog input front‑end for current/voltage in the UR platform.
Origin
GE UR8FV belongs to the GE Multilin UR protection relay product line, which is engineered by GE for transmission and distribution, generation, and industrial protection applications. These modules are produced for global markets under GE’s industrial quality and compliance framework; the design and manufacturing follow utility‑grade standards rather than general‑purpose electronics.
Recommended related GE Multilin UR modules (same brand)
If you are considering UR8FV or building a system around a UR relay, the following related modules from the same GE Multilin UR family are commonly used together:
- UR‑series CPU / main relay units (e.g. UR F‑series or G‑series bases)
The main processor and protection logic platform into which UR8FV is plugged. It runs the protection algorithms (differential, distance, overcurrent, etc.) that use the CT/VT inputs from UR8FV. - UR digital I/O modules (e.g. UR‑8L, UR‑8M types depending on exact catalog numbers)
Provide binary inputs and relay outputs for trip commands, breaker status, interlocking, and signaling. They complement UR8FV by handling the discrete control side. - UR communications modules (Ethernet / serial)
Ethernet and serial communication cards for IEC 61850, DNP3, Modbus, and similar protocols, enabling SCADA and station‑bus integration of the relay that is using UR8FV for analog acquisition. - Other UR CT/VT variants
Some UR models have alternative CT/VT input modules with different ranges or configurations; these are chosen when a different set of CT/VT ratings or special applications (for example, sensitive ground) is required.
All of these are designed to work within the same UR relay chassis and share a common mechanical and configuration environment, so a UR8FV module is usually part of a larger UR relay assembly that also includes CPU, I/O, and communications cards.
