GE UR Series Modules: UR9NH CPU Module,

Technical Dossier

Product Details And Specifications

GE UR Series: Comprehensive Module Range and Technical Overview

The GE Grid Solutions UR (Universal Relay) Series represents one of the most widely deployed digital protection and control platforms in global heavy industry. Installed across chemical processing plants, nuclear power stations, oil refineries, hydroelectric facilities, and high-voltage transmission substations, the UR platform provides a standardized hardware chassis that supports interchangeable function-specific modules. Its modular architecture allows a single relay chassis to be configured for differential protection, distance protection, overcurrent protection, or bay control — without chassis replacement. This flexibility has made the UR Series the de facto standard for protection engineers across North America, Europe, and Asia-Pacific for over two decades.

The Evolution of UR Series Architecture

The UR platform was introduced by GE Multilin in the late 1990s as a successor to the SR Series single-function relays. The original UR chassis used a 19-inch rack-mount form factor with a passive backplane and a proprietary inter-module communication bus. Early firmware revisions (pre-4.0x) supported basic SCADA integration via RS-485 Modbus. From firmware 5.x onward, IEC 61850 GOOSE messaging and IEEE 1588 precision time protocol (PTP) were introduced, enabling peer-to-peer protection schemes without hardwired I/O. The UR2 platform (second-generation) introduced a revised CPU architecture with increased processing throughput, expanded analog input channels, and support for IEC 61968/61970 CIM data models. Compatibility between first- and second-generation modules is chassis-dependent: UR2 CPU modules are not backward-compatible with original UR chassis backplanes. Engineers managing mixed-generation installations must verify chassis revision codes before substituting modules. As of 2024, GE Vernova (the successor entity to GE Grid Solutions) has transitioned active development to the UR2 platform, while the original UR hardware has entered the mature/end-of-active-development phase — making long-term spare parts availability a critical operational concern for asset managers.

UR Series Full Catalog & Functionalities (SKU List)

CPU & Processing Modules

• UR9NH: Second-generation CPU module; dual-core processor, IEC 61850 Ed.2, IEEE 1588 PTP, 256 MB RAM, primary control and logic execution unit for UR2 chassis.
• UR9NX: CPU module variant with extended cybersecurity firmware; NERC CIP-compliant role-based access control, encrypted Ethernet communications.
• UR9GH: First-generation CPU module; single-core DSP, Modbus RTU/TCP, DNP3, compatible with original UR chassis backplane only.
• UR9GX: First-generation CPU with expanded memory; supports larger settings files and extended event recorder capacity (up to 64,000 events).

Digital Input (DI) Modules

• UR8AH: 24-channel digital input module; 24 Vdc/125 Vdc wet contact inputs, optically isolated, 1 ms timestamp resolution.
• UR8AX: 16-channel digital input module; 48 Vdc/250 Vdc input range, suitable for high-voltage substation DC control circuits.
• UR8BH: 32-channel digital input module; mixed voltage range (24–250 Vdc), high-density I/O for bay controller applications.

Digital Output (DO) / Analog Output (AO) Modules

• UR8CH: 16-channel digital output module; Form-A and Form-C relay contacts, 8 A continuous rating, trip and close coil drive capability.
• UR8DH: 8-channel analog output module; 4–20 mA current loop outputs, used for metering and SCADA analog telemetry.
• UR8EH: 24-channel mixed I/O module; 16 DI + 8 DO, compact configuration for space-constrained panels.

Analog Input (AI) / CT/VT Interface Modules

• UR6FH: 8-channel CT/VT analog input module; 1 A / 5 A CT input, 100–240 V VT input, 16-bit ADC, fundamental frequency and harmonic measurement.
• UR6GH: 4-channel CT analog input module; high-accuracy differential current measurement, used in transformer differential protection schemes.
• UR6HH: 12-channel universal analog input; supports CT, VT, and 4–20 mA process inputs on a single module.

Communications & Network Modules

• UR7AH: Dual-port 100BASE-FX fiber Ethernet module; IEC 61850 GOOSE, MMS, and Modbus TCP, SC connector, multi-mode fiber.
• UR7BH: RS-485 / RS-232 serial communications module; Modbus RTU, DNP3 serial, IEC 60870-5-103 protocol support.
• UR7CH: IEEE C37.94 teleprotection interface module; direct fiber-optic channel for pilot protection schemes (POTT, PUTT, DCB).
• UR7DH: GPS / IRIG-B time synchronization module; IRIG-B 000–007 demodulated and modulated input, ±1 µs synchronization accuracy.

Power Supply Modules

• UR5AH: 125/250 Vdc power supply module; 30 W output, redundant supply capable, wide input range 88–300 Vdc.
• UR5BH: 24/48 Vdc power supply module; for low-voltage DC station battery systems, 20 W output.

Sourcing Hard-to-Find & Obsolete UR Series Parts

The original UR platform (first-generation CPU modules including UR9GH and UR9GX) has been classified as end-of-active-manufacturing by GE Vernova. OEM lead times for these modules, when available at all, routinely exceed 26–52 weeks. For power utilities and industrial operators running protection schemes built on first-generation UR hardware, unplanned module failure creates a direct risk to grid reliability and plant safety systems.

DriveKNMS maintains a dedicated inventory of tested, pull-out UR Series modules sourced from decommissioned substations and controlled plant shutdowns. Our procurement network spans North America, Western Europe, and Southeast Asia, enabling us to locate low-circulation SKUs that are no longer accessible through standard distribution channels. For end-of-life modules, we provide a documented chain of custody, including the originating installation site, decommission date, and pre-shipment test records. This documentation is accepted by most utility asset management systems as evidence of module provenance.

Quality Control for the UR Series Range

UR Series modules present specific test challenges due to their integrated backplane communication bus and firmware-dependent calibration. DriveKNMS applies the following test protocol to all UR modules prior to shipment:

• Backplane bus integrity test: Each module is seated in a reference UR chassis and the inter-module communication bus is verified using GE's UR Setup software. Bus error counters must read zero over a 30-minute soak period.
• Firmware version verification: CPU modules are booted and firmware revision is recorded. Modules with firmware below the customer's specified minimum revision are flagged for update or replacement.
• Analog accuracy calibration: CT/VT input modules (UR6xx series) are tested against a calibrated current/voltage injection source. Measurement error must be within ±0.1% of rated input across the full input range.
• Digital I/O functional test: All input channels are exercised with a wet contact simulator. All output relay contacts are actuated and contact resistance is measured (<100 mΩ pass threshold).
• Ethernet port link test: Communications modules are connected to a managed switch and IEC 61850 GOOSE subscription/publication is verified using a protocol analyzer.
• Thermal soak: All modules undergo a 4-hour burn-in at 55°C ambient to screen for early-life component failures.