Description
The GE Multilin UR81H is a high-accuracy Process Bus Module designed for secure and efficient signal acquisition within modern digital substations. It converts analog CT and VT inputs into IEC 61850-compliant sampled values that transmit directly to UR-series relays. The module streamlines protection system architecture and reduces copper wiring, allowing utilities to migrate confidently toward fully digital secondary systems. Moreover, its robust measurement design ensures stable performance even under harsh electrical and environmental conditions.
Key Benefits
The UR81H delivers precise current and voltage sampling that improves relay decision quality in critical protection schemes. In addition, the module supports IEEE 1588 time synchronization, which ensures accurate alignment of phasor and event data across distributed devices. CyberSentry security features strengthen operational resilience and help maintain compliance with NERC CIP expectations. Therefore, engineers can deploy the UR81H in new substations or retrofit projects with minimal integration risk.
Technical Specifications
General
- Model: UR81H
- Series: GE Multilin UR (Universal Relays)
- Type: Process Bus Module for CT/VT digitization
Communication
- Protocol: IEC 61850 Sampled Values
- Ports: 8-port digital process bus interface
- Time Sync: IEEE 1588 PTP
Inputs and Outputs
- CT Nominal Current: 1 A or 5 A (selectable)
- VT Nominal Voltage: 60 V to 240 V AC/DC (model dependent)
- Analog Inputs: Up to 12 (4 current, 4 voltage, 4 RTD/mA)
- Digital Inputs: Multiple, model dependent
- Output Relays: 8 to 16, high-speed or standard
Protection Elements
- ANSI Functions: 49, 50, 51, 66, 46, 27/59, 86, 50/51 N/G, and others
Mechanical & Electrical
- Auxiliary Power: 24–250 V DC or 85–265 V AC/DC
- Weight: 1.15 kg
- Manufacturing Location: Markham, Ontario, Canada
Typical Applications
The UR81H supports digital substation architectures where sampled-value streams replace traditional CT and VT wiring. For instance, it integrates seamlessly into differential protection, busbar protection, and centralized protection platforms requiring synchronized measurements. Utilities also use the module to enhance system flexibility during equipment upgrades or expansion work, reducing installation effort and improving long-term maintainability.
Support & Reliability
GE Multilin engineers designed the UR81H for long service life, even in installations with extreme temperature swings and high electromagnetic stress. Moreover, firmware tools and diagnostic functions simplify ongoing maintenance and help asset owners sustain high system availability. Most distributors offer a standard 12-month warranty, and extended support plans are also available.
FAQ
Q1: What systems are compatible with the UR81H module? The UR81H works exclusively with GE Multilin UR-series protection relays in digital substation networks.
Q2: Does the module support redundant process bus architectures? Yes, it supports multiport IEC 61850 sampled-value communication to enable redundant network designs.
Q3: Can the UR81H operate with mixed 1 A and 5 A CT inputs? Each channel can be configured for the required rating, allowing flexible CT integration.
Q4: How is time synchronization achieved? The module uses IEEE 1588 PTP to maintain accurate timing alignment across all connected devices.
Q5: Is the UR81H suitable for retrofit applications? Yes, it fits into standard UR chassis frames, making it effective for upgrading legacy relay systems without major wiring changes.
