Project overview
Winder Power Ltd, based in Pudsey, Leeds, is a leading UK manufacturer of distribution, power and grid transformers – supporting critical national infrastructure across utilities, transport, industry and renewable energy. Their transformers, some weighing tens of tonnes during testing, require an exceptionally robust and safe high voltage (HV) test environment.
To support their continued innovation and the commissioning of a new HV test laboratory, Winder Power required a fully bespoke earthing system tailored for lightning impulse testing and other high-energy test regimes. Omega Red Group was appointed to design and deliver this specialised earthing infrastructure within a complex existing building layout.
Objectives
- Design and install a fully compliant, high-performance earthing system suitable for a lightning impulse test environment.
- Ensure the test facility could safely dissipate extremely high-energy impulse currents.
- Integrate the earthing system into an existing building with significant structural constraints.
- Collaborate with Winder Power’s international test equipment designers to ensure full compatibility with HV and impulse test specifications.
Scope of works
Technical investigation and design
- Full soil resistivity survey to model ground conditions and inform engineering decisions.
- Development of a bespoke earthing design that accommodated routing restrictions, depth limitations and complex interfaces with existing civil and structural elements.
- Co-ordination with Winder Power’s global equipment suppliers to ensure the system aligned with precise HV and impulse testing requirements.
Key elements of the technical solution included:
- Installation of earth rods via boreholes both inside the test area and externally for generator equipment.
- Construction of a 1m² copper tape earthing grid, providing the core reference point for the entire system.
- Integration of multiple rebar bonding connections to create a robust equipotential zone within the concrete structure.
- Installation of over 250m² of fine copper mesh to control surface voltage gradients.
- Deployment of over 700m of copper tape interlinking all components.
- Completion of more than 350 brazed joints, providing durable, mechanically strong connections capable of withstanding HV impulse conditions.
Challenges
Delivering a system of this scale and sensitivity within an existing building presented several technical and logistical challenges:
- Working within a constrained environment
The facility’s substantial test equipment and dense structural layout required creative routing solutions for cabling and components.
- Ensuring impulse performance
HV impulse testing places extreme demands on an earthing system; every component had to be engineered for reliability under high transient energy conditions.
- Achieving equipotential conditions
Heavy transformer test loads and a reinforced concrete test floor required extensive bonding and integration to avoid hazardous potential differences.
- Co-ordination with international equipment designers
Ensuring the earthing system aligned with the precise performance requirements of the new lightning impulse and HV test equipment.
Despite these challenges, the Omega team adapted rapidly – trialling alternative installation methods, refining the earthing model and adjusting routes and depths as required to achieve the final compliant solution.
Outcome
The project delivered a fully integrated, high-integrity earthing system that now forms the foundation of Winder Power’s new HV test laboratory.
Key outcomes included:
- A safe, compliant environment capable of managing extreme impulse energies.
- Enhanced operational reliability, supporting accurate and repeatable HV and lightning impulse tests.
- Seamless integration with test equipment and building infrastructure.
- Long-term resilience through high-quality materials, robust brazed joints and extensive bonding.
This bespoke system provides Winder Power with a futureproofed test environment that supports their continued role as a major UK transformer manufacturer serving essential infrastructure sectors.
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