GE URSHH Retrofit-Compatible Relay Housing for Legacy Systems

GE URSHH Retrofit-Compatible Relay Housing for Legacy Systems

The GE URSHH is a hardware shelf and housing assembly designed for the GE Multilin UR Series Universal Relay platform — one of the most widely deployed protective relay architectures in power generation, transmission, and industrial automation environments. As the UR Series ages and original OEM supply chains tighten, the URSHH has become a critical retrofit component for facilities managing aging protection panels, legacy control cabinets, and end-of-life relay systems. NINERMAS maintains verified stock of the URSHH with pre-shipment functional testing and a 12-month warranty, supporting maintenance engineers and system integrators who need a reliable, drop-in compatible replacement without full panel redesign.

Whether you are replacing a failed housing assembly, upgrading a legacy protection scheme, or consolidating multiple aging relay platforms into a standardized UR Series architecture, the URSHH provides the mechanical and electrical foundation for a smooth, low-risk retrofit. Its compatibility with the UR Series backplane, power supply modules, and communication cards makes it a preferred choice for brownfield upgrades where minimizing downtime and preserving existing wiring infrastructure are top priorities.

Upgrade Compatibility Table

Retrofit Planning for Existing Automation Systems

Successful integration of the GE URSHH into an existing protection or automation system requires careful pre-engineering to avoid commissioning delays and unplanned downtime. Before removing the legacy housing, maintenance teams should document the current module population — including the URPC CPU module, URPN power supply, URTD digital I/O module, and any installed URFCM fiber communication modules — and photograph all terminal wiring and backplane slot assignments. This documentation becomes the reference baseline for post-installation verification.

In many brownfield sites, the URSHH is installed alongside a GE UR-C60 or GE UR-F35 relay, sharing the same control cabinet and often the same communication network. When the housing is replaced, it is essential to confirm that the IRIG-B time synchronization input, the DNP3 or IEC 61850 communication links, and the analog I/O wiring to current transformers and voltage transformers are reconnected in the correct sequence. Mislabeled terminal blocks are a common source of commissioning errors in legacy panels, and a structured wiring audit using the original relay settings file is strongly recommended before energizing the replacement unit.

For sites running GE UR-G60 generator protection relays or GE UR-C70 line differential relays in the same protection scheme, the URSHH replacement should be coordinated with a review of the inter-relay communication links. Fiber optic connections using the 8FK fiber kit or equivalent multimode fiber assemblies should be inspected for continuity and connector cleanliness before the new housing is commissioned. Any degradation in the fiber link will affect differential protection performance and may trigger false trips during the post-installation test sequence.

Power supply capacity is another critical checkpoint. The URPN module must be verified against the total module load of the populated URSHH chassis. If additional I/O modules or a second URFCM communication card have been added since the original installation, the power budget must be recalculated to confirm the supply is not operating at or near its rated output. In cases where the existing URPN is marginal, a parallel URPP power supply module should be considered as part of the retrofit scope.

For facilities managing multiple aging UR Series housings across a substation or plant, NINERMAS recommends a phased replacement strategy — prioritizing units showing mechanical wear, backplane connector corrosion, or intermittent module seating faults. Maintaining a small buffer stock of URSHH units, along with compatible URPC CPU modules and URTD I/O modules, significantly reduces mean time to repair (MTTR) for protection system faults and supports the long-term spare parts lifecycle of the UR platform.

Downtime Control During System Migration

Minimizing protection system downtime during a URSHH replacement requires a structured outage plan that preserves the original relay logic and communication configuration throughout the swap. The recommended approach is to export the full relay settings file from the existing URPC CPU module using EnerVista UR Setup software before any hardware is disturbed. This settings file captures all protection element parameters, I/O assignments, communication addresses, and HMI display configurations, and serves as the restoration baseline if any issues arise during the housing replacement.

Where possible, the replacement should be performed during a scheduled maintenance window with the protected equipment de-energized and isolated. The outage sequence should include: isolating the relay from the protection scheme, removing all modules from the existing housing in reverse slot order, transferring modules to the new URSHH in the same slot positions, reconnecting all terminal wiring per the documented baseline, and performing a power-on self-test before restoring the relay to service. The entire process for an experienced technician typically requires two to four hours, depending on the number of installed modules and the complexity of the wiring terminations.

For critical protection applications where extended outages are not acceptable, a hot-standby approach using a pre-configured spare URSHH chassis — populated with a programmed URPC module loaded with the current settings file — can reduce the active outage window to under one hour. NINERMAS can supply pre-tested URSHH units with lead times confirmed at order placement, supporting planned maintenance schedules and emergency replacement scenarios alike.

Retrofit Support FAQ

Q1: Is the URSHH a direct replacement for all UR Series housing variants?
The URSHH is compatible with the standard UR Series platform architecture. However, UR Series housings are available in different slot configurations and form factors. Before ordering, confirm the slot count, rack mounting dimensions, and backplane connector type of the unit being replaced. NINERMAS technical support can assist with cross-referencing the existing housing part number to confirm compatibility.

Q2: Does replacing the URSHH require reprogramming the relay?
In most cases, no. The URSHH is a mechanical housing and backplane assembly; the relay logic, protection settings, and communication configuration reside in the URPC CPU module. If the CPU module is transferred intact to the new housing, the relay will resume operation with the existing settings after a successful power-on self-test. A full settings verification using EnerVista UR Setup is recommended after any housing replacement.

Q3: How is the URSHH tested before shipment?
All URSHH units supplied by NINERMAS undergo pre-shipment functional testing, including backplane continuity checks, power supply slot verification, and mechanical inspection of all module guides and connector pins. Units that do not pass the full test protocol are not shipped. A test report is available upon request for quality-critical applications.

Q4: What warranty and inventory support does NINERMAS provide?
NINERMAS provides a 12-month warranty on all URSHH units from the date of shipment. In-stock units are available for immediate dispatch, with lead times for reserved or allocated stock confirmed at order placement. For facilities requiring long-term supply assurance, NINERMAS offers reserved inventory agreements to support multi-year maintenance programs and spare parts lifecycle planning.