Senior Electrical Design Engineer (Primary) in London

Department: OCU Design

Employment Type: Permanent - Full Time

Location: Ruislip

Reporting To: Ed Yeates

Description

Are you an experienced electrical design engineer ready to take technical ownership of safety‑critical primary plant designs for electricity network infrastructure? Do you want to play a leading role in HV and EHV substation projects across the UK? We are seeking a Senior Electrical Design Engineer (Primary) to lead the development, review, and assurance of primary electrical designs within a regulated Distribution Network Operator (DNO) environment. You will act as a technical authority for primary plant design, ensuring compliant, buildable, and cost‑effective solutions across a portfolio of HV and EHV projects. Working closely with a Design Manager who oversees all disciplines, you will be responsible for the delivery of primary designs from feasibility through to detailed design, coordinating closely with civil, protection & control, earthing, and cable system engineers. You will liaise directly with DNO design authorities, project teams, and construction stakeholders to support technical approvals and successful project delivery. Projects span 11kV to 132kV systems, including substation new builds, refurbishments, and reinforcements. Assets include GIS and AIS switchgear, power transformers, disconnectors, circuit breakers, reactors, busbar systems, and associated primary equipment, as well as underground cables and overhead line terminations.

Key Responsibilities

• Primary Design Leadership: Lead the production, review, and approval of HV and EHV primary electrical designs from feasibility through to detailed design, in accordance with DNO standards, ENA specifications, BS EN / IEC standards, and industry best practice. Take technical ownership of primary layouts, single line diagrams, general arrangements, equipment schedules, and interface drawings.
• Safety‑Critical Design Assurance: Deliver safe and compliant primary designs that meet operational, maintenance, and safety requirements under normal and fault conditions. Apply safety‑by‑design principles, ensuring risks are identified, mitigated, and clearly communicated within the design.
• System Studies & Technical Design: Undertake and review key primary design inputs including fault level assessments, equipment ratings, insulation coordination, clearances, and system configuration. Support system studies outputs (e.g. load flow, fault level, and operational flexibility) and translate findings into compliant primary solutions.
• DNO & Stakeholder Engagement: Act as the technical interface with DNO primary and design authorities, responding to comments, securing approvals, and supporting technical submissions and design departures. Contribute to design reviews, client meetings, and technical workshops.
• Multi‑Disciplinary Coordination: Work closely with protection & control, earthing, civil, and cable engineering teams to ensure primary designs are fully integrated with foundations, structures, earthing systems, control buildings, fencing, and cable routes. Ensure interfaces between disciplines are clearly defined and technically coherent.
• Contractor & Site Support: Provide technical support during procurement and construction, including resolving technical queries, reviewing manufacturers’ data, checking as‑built information, and attending site when required. Support construction teams in resolving design‑related issues safely and efficiently.
• Technical Governance & Standards: Ensure compliance with statutory regulations, DNO specifications, and internal procedures. Contribute to continuous improvement of primary design processes, standards, and technical guidance. Provide mentoring and technical guidance to less experienced engineers.

Skills, Knowledge & Expertise

• Experience: Degree qualified in Electrical Engineering or a related discipline. Chartered Engineer (CEng) status or actively working towards chartership. 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.
• Skills: 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.