GE UR8RH (Multilin UR Series) High Precision CT/VT Analog Input Module

GE UR8RH (Multilin UR Series) High Precision CT/VT Analog Input Module

I. Basic Information
Brand: GE Multilin – General Electric
Model: UR8RH
Product Type: 8-channel CT high-precision current transformer acquisition module (with sensitive grounding detection), belonging to the UR series of general relay protection devices and plug-in expandable analog board cards
Host Compatibility: L90 line differential protection, T60 transformer protection, F60 feeder protection, C60 capacitor protection, etc. UR series protection IEDs
Firmware Requirements: Requires host firmware version V4.0 or above. Older versions of the CPU cannot be compatible with this module

Core Hardware Configuration
8-channel CT current input channels, supporting three-phase current, zero sequence, neutral point, and sensitive grounding current acquisition
Sensitive Grounding Detection Function: Sampling sensitivity is 10 times that of ordinary CT modules, specifically adapted for high-resistance grounding systems, capable of accurately capturing weak grounding fault currents
Built-in CT open circuit self-check, overcurrent in the return path, sampling anomaly diagnosis, and real-time fault alarm transmission
Board Bus Hot Swap Design, no power outage for replacing spare parts in the cabinet
Each module can expand up to 8 groups of AC current signals. Multi-module cascading can achieve multi-channel interval sampling

Key Electrical Parameters
Sampling Accuracy: ±0.2 grade, high-precision sampling at the level of power metering
Rated CT Input: 1A/5A, universal selectable
Operating Temperature: -40℃ ~ +70℃, wide temperature industrial-grade design
Insulation Level: Strong and weak electrical high-voltage isolation, anti-electromagnetic interference in accordance with IEC61000
Installation Method: UR series chassis rear-mounted backplane bus installation
Configuration Software: EnerVista UR Debugging Configuration Software

Main Functional Roles
Collecting primary-side three-phase current, zero sequence current of transmission lines, transformers, and generators for differential protection, distance protection, and overcurrent protection to provide precise analog data sources
Highly sensitive grounding fault detection, solving the problem of conventional protection failure in high-resistance grounding situations of overhead lines and cables
Real-time power measurement, fault recording data acquisition, CT circuit online monitoring
Parallel expansion of multiple UR8RH modules to achieve synchronous collection of multiple currents in double busbars, multi-branch circuits

Typical Application Scenarios
110kV/220kV transmission line L90 optical differential protection panel
Main transformer T60 differential protection, plant power feeder F60 protection device
Relay protection for wind power, photovoltaic substation outgoing lines
Power generation unit, substation high-voltage interval measurement and control protection system

Differences of CT Modules in the Same Series Table
Model Channel Configuration Core Features
UR8RH 8 channels of CT + sensitive grounding High-resistance grounding dedicated, high precision, this model
UR7RH 7 channels of CT + 1 channel of VT General current and voltage universal acquisition
UR6CH 6 channels of CT basic model Ordinary protection, low-cost sampling

Common Fault Phenomena
Power-on module of the device fails to recognize, hardware mismatch: Host firmware version is too low
Frequent CT disconnection alarms in protection, sampling value drift, three-phase current imbalance
Protection fails to operate in grounding fault: Incorrect configuration of sensitive grounding channel parameters
Module overheating, no data in sampling channels, internal sampling resistors or transformers damaged