GE UR Series Modules | UR9EV UR 9EV General Electric CPU Module

Technical Dossier

Product Details And Specifications

GE UR Series: Comprehensive Module Range and Technical Overview

The GE UR Series (Universal Relay) platform, developed by GE Grid Solutions (formerly GE Multilin), is one of the most widely deployed digital protection and control relay families in global heavy industry. Installed across high-voltage substations, chemical processing plants, nuclear generating stations, offshore oil platforms, and petroleum refineries, the UR architecture provides a modular, rack-based framework for feeder protection, motor protection, transformer differential, bus differential, and line distance applications. Its installed base spans North America, Europe, the Middle East, and Asia-Pacific, making it a de facto standard for utility-grade protection systems. The UR9EV (UR 9EV) is a CPU/communications module within this platform, responsible for relay logic execution, setting management, and inter-module data exchange over the UR backplane bus.

The Evolution of UR Series Architecture

The UR platform was introduced in the late 1990s as GE Multilin's response to the industry shift from electromechanical and solid-state relays toward fully numerical, IED-based protection. The original UR chassis used a proprietary high-speed backplane bus connecting CPU, I/O, power supply, and communications modules in a 19-inch rack form factor. Early firmware generations (pre-4.x) supported MODBUS RTU and DNP3 serial communications exclusively. From firmware 5.x onward, IEC 61850 GOOSE messaging and MMS protocol support were introduced, enabling UR relays to participate in substation automation networks without protocol converters. The transition to firmware 7.x brought enhanced cybersecurity features aligned with NERC CIP requirements, including role-based access control and encrypted communications. Hardware revision cycles introduced updated CPU modules (such as the UR9EV) with faster processors, expanded memory, and support for IEEE 1588 Precision Time Protocol (PTP) for microsecond-accurate time synchronization. Compatibility between hardware revisions requires careful firmware version matching; mixing early-generation I/O modules with late-generation CPUs may require firmware downgrade or module replacement. The UR platform is now in a mature/sustained phase — GE Grid Solutions continues to supply spare parts and firmware updates, but new feature development is concentrated on the UR-series successor platforms. Long-term maintenance support contracts (LTMS) are available through authorized distributors and third-party MRO suppliers.

UR Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly deployed modules within the GE UR Series platform. Modules are classified by functional category.

CPU & Processing Modules

• UR9EV (UR 9EV): Main CPU module; relay logic execution, setting storage, backplane master control.
• UR9GH (UR 9GH): Enhanced CPU with dual Ethernet ports and IEC 61850 Edition 2 support.
• UR9GT (UR 9GT): CPU module with integrated IEEE 1588 PTP grandmaster clock function.
• UR9G8 (UR 9G8): CPU module supporting dual redundant power inputs and extended temperature range.

Digital Input / Output Modules

• UR8AH (UR 8AH): 16-channel digital input module, 24–250 V DC/AC wet contact sensing.
• UR8AG (UR 8AG): 8-channel digital input / 8-channel output combination module.
• UR8AF (UR 8AF): 24-channel digital output module, Form-A relay contacts, 30 V DC / 250 V AC rated.
• UR8AE (UR 8AE): 16-channel digital output, Form-C relay contacts, high-current interrupting capacity.
• UR8AC (UR 8AC): Fast digital output module for high-speed tripping applications (<4 ms operate time).

Analog Input Modules (CT/VT)

• UR8BA (UR 8BA): 4-channel current transformer (CT) input module, 1 A / 5 A selectable.
• UR8BB (UR 8BB): 8-channel CT input module for multi-winding transformer differential applications.
• UR8BC (UR 8BC): 4-channel voltage transformer (VT) input module, 100–240 V AC nominal.
• UR8BD (UR 8BD): Combined 4-channel CT + 4-channel VT input module for compact installations.

Communications & Adapter Modules

• UR6AH (UR 6AH): Fiber-optic IRIG-B time synchronization and inter-relay communications module.
• UR6AG (UR 6AG): IEEE C37.94 multiplexed teleprotection communications module, 64 kbps.
• UR6AF (UR 6AF): RS-485 / RS-232 serial communications module, MODBUS RTU / DNP3 serial.
• UR6AE (UR 6AE): Dual-port 100BASE-FX fiber Ethernet module for IEC 61850 MMS/GOOSE.

Power Supply Modules

• UR9PA (UR 9PA): 125/250 V DC power supply module, 30 W output, standard UR chassis.
• UR9PB (UR 9PB): 48 V DC power supply module for battery-backed substation DC bus systems.
• UR9PC (UR 9PC): Redundant power supply module, hot-swap capable, for high-availability installations.

Sourcing Hard-to-Find & Obsolete UR Series Parts

As the UR Series enters its sustained-support lifecycle phase, procurement of specific hardware revisions — particularly early-generation CPU modules and legacy communications cards — presents increasing lead-time challenges through OEM channels. DriveKNMS maintains a dedicated inventory of UR Series modules sourced from decommissioned substation equipment, authorized surplus channels, and direct OEM overstock. For end-users operating UR-based protection systems under long-term maintenance agreements, DriveKNMS provides: exact hardware revision matching to avoid firmware incompatibility; cross-reference verification against GE Multilin instruction manuals (GEK-series documents); and expedited shipping for emergency outage support. Modules such as the UR9EV, UR8AH, UR6AH, and UR9PA are stocked as high-priority spares given their failure-critical role in protection relay operation. Inquiries for end-of-life modules not listed above are accepted — DriveKNMS will conduct a sourcing search within 24 hours of receiving a formal parts request.

Quality Control for the UR Series Range

UR Series modules incorporate a high-speed proprietary backplane bus operating at rates that require signal integrity verification beyond standard continuity testing. DriveKNMS applies the following test protocol to all UR Series modules prior to dispatch: (1) Visual inspection of backplane connector pins, FPGA heat spreaders, and capacitor arrays for physical damage or electrolytic leakage. (2) Powered bench test using a UR chassis test fixture: module is seated in a known-good chassis and powered at rated DC input voltage; CPU modules are verified to complete POST (Power-On Self-Test) and achieve HEALTHY LED status within specification. (3) Communications verification: Ethernet modules are tested for link establishment and packet throughput on both ports; serial modules are loopback-tested at all supported baud rates. (4) CT/VT analog input modules are tested with calibrated signal injection to verify measurement accuracy within ±0.1% of rated input. (5) Output relay modules are tested for contact resistance (<100 mΩ) and operate/reset timing against GE Multilin factory specifications. All test records are retained and available upon request with each shipment.

For UR Series module availability, cross-reference support, or emergency spare parts procurement, contact DriveKNMS directly:

• Email: sale@driveknms.com
• WhatsApp: +86 18359293191
• Web: driveknms.com

© 2026 DriveKNMS. All trademarks belong to their respective owners. Specifications are for reference only and subject to change without notice. Verify all parameters against official documentation before installation.