GE UR Series Modules — UR9WH CPU Module

Technical Dossier

Product Details And Specifications

GE UR Series: Comprehensive Module Range and Technical Overview

The GE UR (Universal Relay) Series, developed by GE Grid Solutions (formerly GE Multilin), represents one of the most widely deployed digital protection relay platforms in global heavy industry. Installed across chemical processing plants, nuclear power stations, petroleum refineries, offshore platforms, and high-voltage transmission substations, the UR Series has established a dominant position in mission-critical protection applications where relay reliability directly determines plant uptime and personnel safety. Its modular architecture allows a single chassis to be configured for transformer protection, motor protection, feeder protection, bus differential, and generator protection — making it a universal platform across IEC and ANSI protection schemes.

The Evolution of UR Series Architecture

The UR Series was introduced in the late 1990s as GE Multilin's response to the industry shift from electromechanical and solid-state relays toward fully digital, IED-based protection systems. The platform was built around a modular backplane architecture, where a common chassis accepts interchangeable CPU, I/O, power supply, and communications modules — enabling field reconfiguration without full relay replacement.

Generation 1 (UR Classic, ~1998–2005): Initial deployment with RS-232/RS-485 serial communications, IRIG-B time synchronization, and DNP3.0 protocol support. CPU modules in this era (e.g., UR6AH, UR6WH) operated on proprietary firmware with limited IEC 61850 capability.

Generation 2 (UR Enhanced, ~2005–2012): Introduction of IEC 61850 GOOSE messaging, expanded Ethernet communications (10/100Base-T), and enhanced oscillography recording. Modules such as the UR9WH CPU represent this generation's processing backbone, offering dual-redundant Ethernet ports and expanded memory for event recording.

Generation 3 (UR Advanced / UR-2, ~2012–present): Migration to 32-bit ARM-based processors, IEEE 1588 Precision Time Protocol (PTP), cybersecurity hardening per NERC CIP standards, and expanded analog input channels. Modern equivalents include the UR2AH and UR2WH CPU modules.

Compatibility note: Generation 1 and Generation 2 CPU modules are not directly interchangeable due to backplane connector differences and firmware architecture. I/O modules (digital input, digital output, analog) maintain broader cross-generation compatibility within the same chassis form factor.

UR Series Full Catalog & Functionalities (SKU List)

CPU & Processing Modules

• UR9WH: Generation 2 CPU module; dual Ethernet, IEC 61850, 128MB event storage
• UR6WH: Generation 1 CPU module; RS-485/RS-232, DNP3.0, IRIG-B sync input
• UR6AH: Generation 1 alternate CPU; single serial port, basic oscillography
• UR2WH: Generation 3 CPU; ARM 32-bit, IEEE 1588 PTP, NERC CIP compliant
• UR2AH: Generation 3 alternate CPU; expanded analog processing, dual redundant power

Digital Input (DI) Modules

• UR4AH: 24-channel digital input module; 24/48/125/250 VDC wet contact inputs
• UR4BH: 16-channel digital input module; AC/DC universal input voltage range
• UR4CH: 8-channel high-speed digital input; <1ms pickup time for fast bus protection

Digital Output (DO) Modules

• UR5AH: 16-channel digital output module; Form-A and Form-C relay contacts, 8A rated
• UR5BH: 8-channel high-current output module; 10A continuous, trip-rated contacts
• UR5CH: 24-channel solid-state output module; 100ms operate time, low-burden design

Analog Input (AI) Modules

• UR3AH: 4-channel CT/VT analog input; 1A/5A CT selectable, 0–300V VT input
• UR3BH: 8-channel analog input; expanded current/voltage measurement for transformer differential
• UR3CH: 4-channel transducer input; 4–20mA / 0–10V process variable inputs

Communications & Adapter Modules

• UR7AH: IEC 61850 Ethernet communications module; 100Base-FX fiber, ST connector
• UR7BH: DNP3.0 / Modbus RTU serial communications module; RS-485 isolated port
• UR7CH: IEEE C37.94 inter-relay communications module; multiplexed channel protection

Power Supply Modules

• UR8AH: 125/250 VDC power supply module; redundant input, <20ms holdup on loss of DC
• UR8BH: 24/48 VDC power supply module; low-voltage substation battery systems
• UR8CH: 120/240 VAC power supply module; UPS-backed AC substation applications

Sourcing Hard-to-Find & Obsolete UR Series Parts

The UR Series Generation 1 and early Generation 2 modules (including the UR9WH, UR6WH, UR6AH, UR4AH, UR5AH, UR8AH) have reached end-of-active-production status with GE Grid Solutions. OEM lead times for these modules — when available — frequently exceed 26–52 weeks, and in many cases GE has formally discontinued the part with no direct replacement stocked through standard distribution channels.

DriveKNMS maintains a dedicated inventory of tested, pull-out, and refurbished UR Series modules sourced from decommissioned substations, plant upgrades, and controlled surplus channels globally. Our procurement network covers North America, Europe, Southeast Asia, and the Middle East — the primary regions where UR Series relays remain in active service under long-term maintenance contracts.

For end-users operating UR Series relays under 10–20 year maintenance agreements (common in nuclear and petrochemical facilities), DriveKNMS provides lifecycle extension support including: module-level replacement without chassis swap, firmware version matching to avoid protection setting migration, and batch procurement for multi-unit substation standardization.

Quality Control for the UR Series Range

UR Series modules present specific test challenges due to their integrated backplane bus architecture and IEC 61850 GOOSE communication dependencies. DriveKNMS applies the following test protocol to all UR Series modules prior to shipment:

• Backplane bus continuity test: All edge connector pins verified against GE Multilin UR Hardware Manual (GEK-113500) pinout specifications.
• CPU module boot verification: Module powered in a live UR chassis; firmware version confirmed, self-test diagnostics passed, no latched fault codes.
• Ethernet port functional test: For modules with Ethernet (e.g., UR9WH), both ports tested for 100Base-TX link establishment and GOOSE packet transmission.
• Analog input calibration check: CT/VT input modules tested with calibrated current injection at 1A and 5A; accuracy verified within ±0.1% of rated input.
• Digital I/O contact resistance test: Output relay contacts measured for contact resistance (<100mΩ); input optocoupler pickup/dropout voltage verified.
• Thermal soak: All modules subjected to 4-hour burn-in at 55°C to screen early-life failures before shipment.