GE URRHH Power Module

Technical Dossier

Product Details And Specifications

GE URRHH Series Technical Notes

The Evolution of URRHH Architecture

The URRHH module traces its lineage to GE's Speedtronic Mark I and Mark II turbine control systems introduced in the 1960s and 1970s, which used discrete relay logic and analog signal conditioning. The Mark IV generation, introduced in the early 1980s, transitioned to digital microprocessor-based control and established the modular rack architecture that the URRHH power supply was designed to serve. The Mark V, released in the late 1980s and widely deployed through the 1990s, retained backward-compatible power distribution topology, allowing URRHH modules to operate across both generations with minimal hardware modification.

By the mid-2000s, GE introduced the Mark VI and Mark VIe platforms, which adopted a fundamentally different I/O and power architecture based on distributed I/O packs (IONet) and eliminated the centralized backplane power model used by URRHH. This architectural break means URRHH modules are not forward-compatible with Mark VI or VIe systems. Operators running Mark IV or Mark V installations face a binary choice: maintain the existing power supply infrastructure using genuine or equivalent URRHH spares, or undertake a full control system upgrade to Mark VI/VIe — a capital-intensive project typically deferred until a major outage window. As a result, demand for URRHH and its associated power module family remains stable in the MRO (maintenance, repair, and operations) market despite the series being formally discontinued by GE.

URRHH Full Catalog & Functionalities (SKU List)

The following SKUs represent the core power supply and associated module range compatible with GE Speedtronic Mark IV and Mark V control systems. Each entry reflects a verified part number within the GE Speedtronic ecosystem:

URRHH: Primary DC power supply module for Mark IV/V control racks; regulated output for logic and I/O buses.
URRHI: Redundant power supply module; hot-standby configuration for continuous-duty turbine control panels.
URRHG: Power conditioning module; filters and regulates incoming AC supply before conversion to DC logic voltage.
URRHE: Auxiliary power module; dedicated supply rail for communication and interface subsystems.
URRHD: Low-voltage DC distribution module; routes regulated power to individual I/O module slots in the Mark V rack.
URRHC: Power monitor module; supervises voltage rail integrity and triggers fault relay on out-of-tolerance conditions.
URRHB: Backup power interface module; manages transition between primary supply and UPS input during grid disturbances.
URRHF: Field power supply module; provides isolated 24 VDC output for field transmitter and sensor loops.
DS200URRHH1A: Full assembly part number for URRHH module with revision A PCB; standard replacement unit for Mark V R-type racks.
DS200URRHH1B: Revision B variant of the URRHH assembly; incorporates updated capacitor specification for extended thermal tolerance.
DS200URRHI1A: Full assembly for URRHI redundant supply; paired with URRHH in dual-supply rack configurations.
DS200URRHG1A: Full assembly for URRHG power conditioning module; required upstream of URRHH in high-harmonic-distortion environments.
DS200URRHD1A: Full assembly for URRHD distribution module; direct slot replacement in Mark V R-rack power bay.
DS200URRHF1A: Full assembly for URRHF field supply; UL-listed isolated output for hazardous-area transmitter loops.
DS200URRHC1A: Full assembly for URRHC power monitor; includes relay output for integration with plant DCS alarm system.
IS200URRHH1A: IS200-series variant of URRHH; used in Mark VI transitional rack configurations requiring backward power compatibility.
IS200URRHI1A: IS200-series redundant supply variant; supports dual-supply architecture in mixed Mark V / Mark VI migration racks.

Quality Control for the URRHH Range

Power supply modules in the URRHH family present specific test challenges due to their role in supplying regulated voltage to active backplane buses. A failed or marginal URRHH unit that passes basic bench continuity checks may still introduce voltage ripple, transient spikes, or load-regulation errors that cause intermittent faults in downstream I/O and CPU modules — failure modes that are difficult to diagnose without rack-level load simulation.