GE UR Series Modules | UR6AH Digital I/O 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), is one of the most widely deployed protection relay platforms in global heavy industry. Installed across chemical processing plants, nuclear power stations, oil refineries, offshore platforms, and high-voltage transmission substations, the UR Series provides a standardized, modular chassis architecture that supports a broad range of protection, control, and monitoring functions. Its scalability — from single-function feeder protection to complex multi-function bay controllers — has made it the reference platform for utility-grade protection engineering across North America, Europe, and Asia-Pacific for over two decades.

The Evolution of UR Series Architecture

The UR platform was introduced in the late 1990s as GE Multilin's answer to the demand for a unified, IED-based protection relay that could replace discrete electromechanical and solid-state relays across multiple bay types. The first-generation UR chassis used a passive backplane with a proprietary inter-module communication bus, allowing CPU, I/O, power supply, and communications modules to be mixed and matched within a standard 19-inch rack form factor.

Early UR firmware (pre-v4.0x) supported MODBUS RTU and DNP3 as primary SCADA protocols. With the release of the UR firmware v5.x and v6.x generations, IEC 61850 GOOSE messaging and MMS became standard, enabling peer-to-peer tripping and station bus integration without hardwired intertripping. The UR platform also evolved to support IEEE 1588 Precision Time Protocol (PTP) for sub-microsecond time synchronization, critical for differential protection schemes.

Compatibility note: UR modules are chassis-slot specific. CPU modules (e.g., UR6DH, UR6EH) are not interchangeable with I/O modules (UR6AH, UR6BH) without reconfiguring the chassis slot assignments. Firmware versions must be matched across CPU and DSP modules to avoid boot failures. Older UR1xx-chassis modules are not backward compatible with UR6xx-chassis hardware.

UR Series Full Catalog & Functionalities (SKU List)

Digital I/O Modules

• UR6AH: 16-channel digital input/output module for UR6 chassis; supports wet/dry contact inputs and relay output contacts rated to 250 VAC/8A.
• UR6BH: Enhanced digital I/O module with 24 configurable channels; supports high-speed binary input capture for event recording at 1 ms resolution.
• UR6CH: Analog I/O module; 4 analog inputs (4–20 mA / 0–10 V) and 2 analog outputs for transducer interfacing and metering output.

CPU / DSP Modules

• UR6DH: Main CPU module for UR6 platform; dual-core processor, 512 MB RAM, supports IEC 61850 Ed.2, DNP3, MODBUS TCP/IP.
• UR6EH: DSP co-processor module; handles real-time phasor calculation and protection algorithm execution at 64 samples/cycle.
• UR6FH: Redundant CPU module for hot-standby configurations; automatic failover in <100 ms upon primary CPU fault detection.

Power Supply Modules

• UR6PH: 125/250 VDC station battery power supply module; wide input range 88–300 VDC, output 5 VDC/3 A and 24 VDC/1 A internal rails.
• UR6QH: AC power supply module; 100–240 VAC input, suitable for substations with AC auxiliary supply; includes inrush current limiting.
• UR6RH: Redundant power supply module; parallel operation with UR6PH/UR6QH for N+1 redundancy; hot-swappable without relay de-energization.

Communications Modules

• UR6GH: Dual-port Ethernet communications module; 100BASE-TX, supports IEC 61850 MMS/GOOSE, IEEE 1588 PTP, SNTP time sync.
• UR6HH: Fiber optic communications module; ST connectors, 820 nm multimode; for inter-relay GOOSE over fiber in high-EMI environments.
• UR6JH: Serial communications module; RS-485 and RS-232 ports; supports MODBUS RTU, DNP3 serial, IEC 60870-5-103.
• UR6KH: IEEE C37.94 teleprotection interface module; for direct transfer trip over multiplexed fiber channels; 64 kbps channel rate.

CT/VT Input Modules

• UR6LH: Current transformer input module; 8 CT inputs, rated 1 A / 5 A selectable; burden <0.1 VA at rated current; for differential and overcurrent protection.
• UR6MH: Voltage transformer input module; 4 VT inputs, rated 100–120 V line-to-line; for distance, voltage, and frequency protection elements.
• UR6NH: Combined CT/VT input module; 4 CT + 4 VT inputs in single slot; optimized for compact UR chassis configurations in space-constrained panels.

Specialty / Application Modules

• UR6SH: Synchrophasor (PMU) output module; IEEE C37.118.1 compliant; outputs real-time phasor data over Ethernet for wide-area monitoring systems.
• UR6TH: RTD/thermocouple input module; 8 RTD inputs (PT100/PT1000) or 4 thermocouple inputs; for transformer thermal protection and motor winding monitoring.

Sourcing Hard-to-Find & Obsolete UR Series Parts

The GE UR Series entered its mature lifecycle phase in the mid-2010s. While GE Grid Solutions (now part of GE Vernova) continues to support the platform with firmware updates and limited hardware production, many first- and second-generation UR modules — particularly those with the UR1xx and UR4xx chassis designations — have been formally discontinued. Lead times for new production units of specific I/O and communications modules can extend to 26–52 weeks through OEM channels.

DriveKNMS maintains a dedicated inventory of tested, refurbished, and new-surplus UR Series modules sourced from decommissioned substation projects, utility equipment auctions, and authorized distributor overstock. Our inventory covers the full UR6xx chassis module range, including hard-to-find CPU variants and legacy communications cards. For end-users operating UR-based protection schemes beyond the OEM's active support window, DriveKNMS provides lifecycle extension services including module-level testing, firmware version verification, and long-term consignment stocking agreements.

Quality Control for the UR Series Range

UR Series modules present specific test challenges due to their backplane-dependent initialization sequence and firmware-locked configuration binding. DriveKNMS applies the following test protocol to all UR Series modules prior to dispatch:

• Backplane simulation test: Each module is inserted into a live UR6 test chassis to verify correct slot recognition, inter-module bus handshake, and firmware boot sequence completion.
• I/O functional verification: For digital I/O modules (including UR6AH), all input channels are exercised with calibrated contact closure signals; all output relay contacts are tested for continuity, coil resistance, and rated switching capacity.
• CT/VT accuracy test: Current and voltage input modules are tested against a precision relay test set (Omicron CMC 356 or equivalent) to verify metering accuracy within ±0.2% of rated input.
• Communications link test: Ethernet and serial communications modules are tested for IEC 61850 GOOSE subscription/publication, MODBUS register polling, and DNP3 unsolicited response at rated baud rates.
• Thermal burn-in: All refurbished modules undergo 48-hour powered burn-in at 50°C ambient to screen for latent component failures before shipment.