Location: Ruislip, United Kingdom
Contract: Permanent
Working Pattern: Full-Time
Renumeration Indicator: Competitive salary plus company vehicle, pension and private healthcare. Remuneration for this role is benchmarked competitively within the Infrastructure and energy sector, and sits within our D2 band, reflecting the seniority and scope of the position.
The Opportunity
Join us as a Senior Electrical Design Engineer (Primary), where you’ll take technical ownership of safety-critical HV and EHV primary plant designs for UK electricity network infrastructure, leading the delivery of compliant, buildable, and cost-effective solutions across substation projects from 11kV to 132kV. Working within a regulated DNO environment, you’ll collaborate across multi-disciplinary engineering teams and engage directly with stakeholders to ensure successful project delivery from feasibility through to detailed design.
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Lead the development, review, and approval of safe, compliant HV and EHV primary electrical designs from feasibility through to detailed design, ensuring alignment with DNO standards, ENA specifications, and industry best practice.
- Drive safety and reliability outcomes by applying safety-by-design principles and ensuring primary plant designs are fully assessed for operational, maintenance, and fault condition risks.
- Improve system performance and design quality by undertaking and interpreting key studies and technical inputs, including fault level assessments, equipment ratings, insulation coordination, and system configuration.
- Secure timely technical approvals and reduce project delays by acting as the key interface with DNO design authorities, managing submissions, design reviews, and technical discussions.
- Enable fully integrated, buildable solutions by collaborating across protection & control, earthing, civil, and cable design teams to ensure seamless multi-disciplinary coordination.
- Support successful project delivery on site by resolving technical queries, reviewing vendor and as-built information, and providing practical engineering support during procurement and construction.
- Strengthen engineering standards and capability by ensuring compliance, driving continuous improvement in design processes, and providing mentoring and technical guidance to junior engineers.
Essential:
- Degree qualified in Electrical Engineering or a related discipline.
- Significant experience delivering HV and EHV primary electrical designs for UK electricity network projects.
- Strong understanding of DNO standards, procedures, and assurance processes.
- Proven experience with GIS and AIS substation primary plant.
- Solid knowledge of UK electrical safety regulations and CDM requirements.
- Strong understanding of primary plant design principles, equipment selection, clearances, insulation coordination, and system operation.
- Ability to interpret and apply ENA, BS EN, IEC, and DNO‑specific standards.
- Confident producing and checking primary layouts, SLDs, design reports, and technical schedules.
- Strong technical writing skills with the ability to clearly justify design decisions to clients and authorities.
Desirable:
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Chartered Engineer (CEng) status or actively working towards chartership.
At OCU Group, we don’t just deliver infrastructure - we help power modern life.
As one of the UK’s fastest-growing utility and infrastructure businesses, we deliver complex, nationally critical projects across power, energy transition, water, telecoms, and digital infrastructure. Over the last five years, OCU has grown five-fold to a £1.1bn organisation, expanding both organically and through strategic acquisitions across the UK, Australia, New Zealand and India.
Our growth is driven by ambitious people, operational excellence, and a commitment to doing things properly. We work on projects that genuinely matter by supporting the UK’s energy transition, strengthening essential infrastructure, and helping build more sustainable communities for the future.
Whether you’re an experienced professional looking to take ownership of major projects and influence delivery at scale, or someone starting your career through an apprenticeship, graduate programme, or placement route, OCU offers real opportunity to grow, develop, and make an impact.
We are building a business where high performance, collaboration, innovation, and accountability sit at the centre of our culture. Our people are trusted to lead, encouraged to challenge thinking, and supported to continuously develop their skills and careers.
At OCU, you won’t just join a growing business, you’ll help shape it.
Our Culture & Values
At OCU, our values are at the heart of everything we do. We care about safety, lead with integrity, strive to be better every day, make a positive impact, and deliver to grow, together, as One Company United.
Our Commitment to Inclusion
At OCU Group, we believe diversity, inclusion, and belonging are fundamental to building stronger teams, better ideas, and a more successful business. We welcome applications from people of all backgrounds and are committed to creating an environment where everyone feels valued and supported.
As part of our commitment to fairness and equality, candidates may be asked to complete an equal opportunities monitoring form during the recruitment process. This information is used for monitoring purposes only and plays no part in hiring decisions.
We are proud to be a Disability Confident employer and are committed to offering interviews to candidates with disabilities or long-term health conditions who meet the essential criteria for the role.
To ensure that everyone has a fair opportunity to join our team, please inform us if you require any reasonable adjustments to our recruitment and interview process is, by emailing
[email protected].
