GE UR Series Modules

Technical Dossier

Product Details And Specifications

GE UR Series: Comprehensive Module Range and Technical Overview

The GE UR (Universal Relay) Series represents one of the most widely deployed protection relay platforms in global heavy industry. Installed across chemical processing plants, nuclear power stations, oil refineries, and high-voltage transmission substations, the UR platform has established a dominant position in mission-critical protection applications. Its modular architecture allows utilities and industrial operators to configure relay functions—differential protection, distance protection, overcurrent, and busbar protection—within a single standardized chassis. The UR Series is recognized by grid operators in North America, Europe, and Asia-Pacific as a benchmark platform for IEC 61850-compliant substation automation.

The Evolution of UR Series Architecture

The GE UR platform was introduced in the late 1990s as a successor to GE's earlier electromechanical and static relay families. The first-generation UR chassis established the 19-inch rack-mount form factor with a passive backplane bus, supporting hot-swappable I/O modules. Early firmware revisions (UR 3.x and 4.x) provided MODBUS RTU and DNP3 communications. The UR 5.x generation introduced IEC 61850 GOOSE messaging and expanded analog input density. The UR 6.x and 7.x releases added IEEE 1588 Precision Time Protocol (PTP) synchronization, enhanced cybersecurity hardening (NERC CIP compliance), and expanded CT/VT input configurations. Compatibility between generations is maintained at the chassis level; however, CPU and communications modules from different firmware generations require careful version matching. Many UR 3.x and 4.x CPU modules are now discontinued, creating a sustained demand for tested surplus and refurbished units to support long-lifecycle substation assets.

UR Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly deployed modules within the GE UR platform, organized by functional category:

CPU & Main Processing Modules

• UR73FH: UR Series CPU module, dual-redundant Ethernet, IEC 61850 GOOSE, IEEE 1588 PTP sync
• UR6FH: UR Series CPU, single Ethernet port, DNP3/MODBUS, standard protection firmware
• UR7FH: UR Series CPU, enhanced processing, dual-port fiber Ethernet, cybersecurity hardened
• UR8FH: UR Series CPU, high-density I/O support, IEC 61850 Ed.2, NERC CIP compliant

Digital Input (DI) Modules

• UR-8D: 8-channel digital input module, 24–250 VDC wet contact, optically isolated
• UR-16D: 16-channel digital input module, configurable threshold voltage, high-speed scan
• UR-32D: 32-channel digital input module, expanded DI density for large switchgear applications

Digital Output (DO) / Relay Output Modules

• UR-8R: 8-channel relay output module, Form-C contacts, 30 VDC / 250 VAC rated
• UR-16R: 16-channel relay output module, high-speed trip output, latching and non-latching modes
• UR-4R: 4-channel high-current relay output, 10 A continuous, for direct breaker trip circuits

Analog Input (AI) Modules

• UR-4CT: 4-channel CT input module, 1 A / 5 A selectable, metering and protection class
• UR-8CT: 8-channel CT input module, high-density current measurement, differential protection use
• UR-4VT: 4-channel VT input module, 100–240 VAC nominal, distance and voltage protection

Communications & Networking Modules

• UR-C72: Dual-port 100BASE-FX fiber Ethernet communications module, IEC 61850 GOOSE
• UR-C73: Dual-port copper Ethernet module, IEEE 1588 PTP, SNTP time synchronization
• UR-C74: RS-485 serial communications module, MODBUS RTU / DNP3 serial protocol support

Power Supply Modules

• UR-PSU125: 125 VDC station battery power supply module, wide input range 88–150 VDC
• UR-PSU250: 250 VDC power supply module, redundant supply support, internal fuse protection

Sourcing Hard-to-Find & Obsolete UR Series Parts

A significant portion of the installed UR Series base operates on firmware generations and hardware revisions that GE Grid Solutions (now GE Vernova) has transitioned to end-of-active-support status. CPU modules from the UR 3.x and 4.x generations, specific I/O modules with legacy backplane pinouts, and early communications cards are no longer available through standard distribution channels. DriveKNMS maintains a dedicated inventory of tested surplus UR Series modules sourced from decommissioned substations, controlled shutdowns, and verified surplus stock. Each unit undergoes functional verification before listing. DriveKNMS provides cross-reference support to identify compatible replacement modules where direct equivalents are unavailable, and can assist engineering teams in evaluating firmware compatibility between replacement CPUs and existing chassis configurations. For long-term maintenance contracts on UR-equipped substations, DriveKNMS offers reserved stock agreements to guarantee availability of critical spare modules over multi-year maintenance windows.

Quality Control for the UR Series Range

The GE UR Series employs a passive backplane architecture with a proprietary high-speed serial bus connecting all installed modules to the CPU. Quality verification for UR modules requires specialized procedures beyond standard power-on testing. DriveKNMS applies the following protocol to all UR Series inventory: (1) Visual inspection of backplane connector pins for corrosion, mechanical deformation, and ESD damage; (2) Powered bench test using a UR chassis with known-good reference modules to verify backplane bus communication; (3) Firmware version identification and logging for all CPU modules; (4) Functional test of all I/O channels on DI, DO, and AI modules using calibrated signal sources; (5) Ethernet port continuity and link negotiation test for all communications modules; (6) Thermal cycling verification for modules sourced from outdoor or high-ambient-temperature installations. Test records are retained and available upon request for critical spare applications.