GE Multilin UR Series Modules UR6TH

Technical Dossier

Product Details And Specifications

GE Multilin UR Series Technical Notes

The GE Multilin Universal Relay (UR) platform is one of the most widely deployed protection and control relay architectures in global heavy industry. Installed across petrochemical complexes, nuclear generating stations, offshore oil platforms, and high-voltage transmission substations, the UR series provides a modular, rack-based hardware framework that supports a broad range of protection functions — distance, differential, overcurrent, busbar, and motor protection — within a single standardized chassis. Its architecture is recognized by utilities and industrial operators in North America, Europe, the Middle East, and Asia-Pacific as a long-cycle asset with typical field service lives exceeding 15–20 years. The modular slot-based design allows individual function cards to be replaced without disturbing the entire relay assembly, making spare parts inventory management a critical operational discipline for any facility running UR-based protection schemes.

The Evolution of Multilin UR Architecture

The UR platform was introduced by GE Multilin (now GE Grid Solutions) in the late 1990s as a successor to discrete single-function electromechanical and early digital relays. The first-generation UR chassis established the 19-inch rack form factor with a passive backplane and a slot-addressed module bus. Early firmware revisions (UR 2.x and 3.x) supported IEC 61850 Edition 1 GOOSE messaging and DNP3 serial communications, which were the dominant SCADA protocols of that era.

The second-generation UR platform (firmware 4.x–5.x) introduced enhanced cybersecurity features aligned with NERC CIP standards, expanded analog input channel counts, and support for IEC 61850 Edition 2 with RSTP network redundancy. Hardware modules were redesigned with improved EMC shielding to meet IEC 61000-4 immunity levels required for substation environments.

Current-generation UR hardware (firmware 7.x) supports IEEE 1588 Precision Time Protocol (PTP) for microsecond-level time synchronization, expanded fiber-optic inter-relay communications, and enhanced event recording with 1 ms resolution. Compatibility between first-generation and current-generation modules within the same chassis is limited; slot assignments and backplane bus protocols must be verified against the specific chassis revision before substituting modules. Facilities operating legacy UR 2.x or 3.x firmware are advised to maintain a dedicated spare parts pool, as firmware downgrade paths are not supported by GE Grid Solutions for modules manufactured after 2018.

Multilin UR Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked modules within the GE Multilin UR platform. Each entry reflects the module's primary function as defined in GE Grid Solutions product documentation.

CPU & Control Modules

• UR6TH: CPU module with dual Ethernet, IEC 61850 Ed.2, IEEE 1588 PTP time sync support
• UR6AH: Advanced CPU module with enhanced processing capacity for complex protection schemes
• UR6CH: CPU module variant with expanded communications port configuration
• UR6DH: CPU module with integrated fiber-optic inter-relay communications interface

Analog Input (AI) Modules

• UR7AH: 8-channel CT/VT analog input module, 1 A / 5 A selectable, 16-bit ADC
• UR7BH: 4-channel CT analog input module optimized for differential protection applications
• UR7CH: 8-channel VT analog input module with extended voltage range for 230 kV class applications
• UR7DH: 4-channel transducer input module, 4–20 mA / 0–10 V DC process signal inputs

Digital Input (DI) Modules

• UR8AH: 24-channel digital input module, 24–250 V DC wet contact inputs
• UR8BH: 16-channel digital input module with high-speed capture, 1 ms resolution
• UR8CH: 24-channel digital input module, AC/DC universal input voltage range

Digital Output (DO) / Relay Output Modules

• UR9AH: 16-channel relay output module, Form-C contacts, 8 A continuous rating
• UR9BH: 8-channel high-current relay output module, 30 A make / 10 A carry
• UR9CH: 24-channel solid-state output module for high-cycle switching applications

Communications & Adapter Modules

• UR6PH: IEC 61850 GOOSE / MMS dual-port fiber Ethernet communications module
• UR6QH: DNP3 / Modbus RTU serial communications adapter, RS-485 / RS-232
• UR6RH: IEEE C37.94 multiplexed teleprotection channel interface module

Power Supply Modules

• URPSH: 125/250 V DC redundant power supply module, 40 W output
• URPTH: 24/48 V DC power supply module for low-voltage DC substation battery systems

Sourcing Hard-to-Find & Obsolete Multilin UR Parts

GE Grid Solutions formally discontinued first-generation UR hardware (modules with suffix -AH and early -BH revisions manufactured prior to 2010) from active production. Repair and calibration support through GE's authorized service network for these modules ended in 2022. For facilities that cannot execute a full relay replacement program due to capital budget constraints or outage scheduling limitations, DriveKNMS maintains a global sourcing network for legacy UR modules.

Quality Control for the Multilin UR Range

The UR platform's backplane-addressed module bus requires that each replacement module be validated not only for standalone electrical function but also for correct backplane communication handshake behavior. DriveKNMS applies the following test protocol to all UR modules prior to dispatch:

• Backplane Bus Integrity Test: Each module is seated in a live UR chassis test fixture and verified for correct slot-address recognition and inter-module communication via the internal module bus.
• Analog Channel Calibration Verification: AI modules (CT/VT inputs) are tested against NIST-traceable reference standards at 1 A, 5 A, and rated voltage levels. Accuracy is verified to within ±0.1% of rated value.
• Digital I/O Functional Test: All DI channels are exercised across the full rated input voltage range. All DO relay contacts are tested for make/break continuity and contact resistance (<100 mΩ).
• Firmware Version Audit: CPU modules are booted and firmware version is recorded. Modules are supplied with firmware version documentation to allow the end user to verify compatibility with their existing chassis revision.
• Dielectric Withstand Test: Modules are subjected to a 500 V DC insulation resistance test between signal commons and chassis ground, with a minimum acceptable result of 100 MΩ.