GE UR Series Modules: UR6GH 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 petrochemical complexes, nuclear power stations, offshore oil platforms, and high-voltage transmission substations, the UR platform provides modular, bay-level protection and control for generators, transformers, motors, feeders, and bus systems. Its slot-based chassis architecture allows field engineers to configure relay functionality by populating specific module slots — CPU, I/O, communications, and power supply — without replacing the entire relay chassis. This design philosophy has made the UR Series the backbone of protection schemes in facilities where continuous uptime is non-negotiable.

The Evolution of UR Series Architecture

The UR platform was introduced in the late 1990s as a successor to GE Multilin's earlier SR Series relays. The first-generation UR chassis used a 19-slot backplane with a proprietary high-speed inter-module bus (HIIB) operating at 10 Mbps, enabling deterministic real-time data exchange between CPU and I/O modules. Early firmware versions (3.x and 4.x) supported IEC 61850 Edition 1 via optional communications modules. By the mid-2000s, GE released the UR 7.x firmware generation, adding IEC 61850 Edition 2 GOOSE messaging, IEEE 1588 precision time protocol (PTP) synchronization, and expanded analog I/O resolution to 16-bit ADC. The UR 8.x generation introduced cybersecurity hardening aligned with NERC CIP standards, role-based access control (RBAC), and encrypted Ethernet communications. Compatibility between generations is slot-position dependent: CPU modules from the 7.x era are not backward-compatible with 3.x-era backplanes without firmware bridge upgrades. I/O modules such as the UR6GH are generally chassis-agnostic within the same physical form factor generation, but engineers must verify backplane revision codes before substitution.

UR Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked modules within the GE UR Series platform. Each module occupies one or more slots in the UR chassis and performs a discrete function within the relay's protection or control architecture.

UR6GH: 16-channel digital I/O module; 8 optically isolated inputs + 8 output contacts for bay-level control logic.
UR6AH: Analog I/O module; 4 analog inputs (0–20 mA / 4–20 mA) + 2 analog outputs for transducer interfacing.
UR6CH: High-density contact I/O module; 16 dry-contact inputs rated for 24–250 VDC/VAC field wiring.
UR6DH: Digital output module; 16 Form-A relay output contacts, 5 A continuous, for trip and alarm circuits.
UR6EH: Mixed I/O module; 8 digital inputs + 4 Form-C relay outputs for combined protection/control schemes.
UR6FH: Fast digital I/O module; sub-4 ms response time inputs for high-speed bus protection applications.
UR6JH: Transducer input module; 4 channels, ±10 V / 0–20 mA, for power quality and metering integration.
UR6KH: RTD input module; 8 channels, PT100/PT1000 compatible, for thermal protection of motors and transformers.
UR6LH: Thermocouple input module; 8 channels, Type J/K/T, for high-temperature process monitoring.
UR6PH: Power supply module; 125/250 VDC input, redundant-capable, for UR chassis primary power.
UR6QH: Redundant power supply module; hot-swap capable, for N+1 power redundancy configurations.
UR6RH: CPU module (standard); dual-core processor, 512 MB RAM, IEC 61850 Ed.2, DNP3, Modbus TCP.
UR6SH: CPU module (enhanced); adds IEEE 1588 PTP, NERC CIP cybersecurity, and expanded event log capacity.
UR6TH: Ethernet communications module; dual 100BASE-TX ports, GOOSE publisher/subscriber, SNTP client.
UR6UH: Serial communications module; RS-485 / RS-232, Modbus RTU, DNP3 serial for legacy SCADA integration.
UR6VH: Fiber optic communications module; ST-connector, 820 nm multimode, for electrically noisy substation environments.
UR6WH: GPS/IRIG-B time synchronization module; IRIG-B 004/006 input, ±1 µs accuracy for fault recording timestamps.

Sourcing Hard-to-Find & Obsolete UR Series Parts

Quality Control for the UR Series Range

The UR Series backplane uses a proprietary HIIB bus with strict timing tolerances. Standard bench testing protocols are insufficient for validating module integrity in this platform. DriveKNMS applies a multi-stage test procedure specific to UR architecture: (1) Visual inspection for backplane connector pin deformation, capacitor ESR degradation, and conformal coating integrity on I/O modules exposed to high-humidity environments. (2) Powered slot insertion test using a reference UR chassis to verify HIIB enumeration and module self-test pass status. (3) For digital I/O modules including the UR6GH, all 16 I/O channels are exercised individually using a programmable relay tester to confirm contact resistance (<100 mΩ), optical isolator threshold voltage, and output coil pull-in/drop-out timing. (4) CPU modules undergo firmware version verification, non-volatile memory integrity check, and Ethernet port loopback test. (5) Power supply modules are load-tested at 100% rated output for 30 minutes with thermal imaging to identify failing capacitor banks before shipment.