Medium Voltage

Delta HV undertakes projects from 1kV – 33kV, including:

  • Substation replacement / refurbishment / extension – indoor and open terminal
  • Switchboard replacement / extension
  • Transformer replacement
  • Cable installation

With Delta HV’s team of motivated individuals, we offer construction and commissioning of projects in a safe, professional, timely and cost efficient manner.

High Voltage

Delta HV undertakes electrical infrastructure projects from 66kV – 400kV, including:

  • Substation replacement / refurbishment / extension – indoor and open terminal
  • Switchboard replacement / extension
  • Transformer replacement
  • Cable installation management

Our experienced skillset enables us to carefully plan and execute the most complex of projects, including any contingency arrangements required.

Senior Authorised Persons (up to 132kV)

As part of our dedicated team we can offer 11kV, 33kV and 132kV SAP services required for management of safety and switching on DNO sites.

Project Management

Delta HV offers project management services for the most complex of electrical infrastructure projects. With a track record of unparalleled safety and quality control on projects, we can deliver complete turnkey projects in house on time and within budget.

We value our Clients, and to this end provide regular, accurate progress reporting throughout the project life-cycle.

Site Management

As part of our turnkey solution, Delta HV offers site management capabilities to our Clients. With vast experience in site management, we understand the pressures during the delivery phase and can offer safe, quality and efficient management of on-site construction.

Our management of delivery works also extends to supervision and coordination of civil, structural and site infrastructure works.

Site Installation Works

Delta HV believe quality starts at the top and our experienced site management capabilities coupled with our close working relationship with an external labour organisation, ensure electrical installation works are completed in a safe, timely and quality controlled manner.

Our experienced delivery team have first hand experience ensuring every activity is undertaken in accordance with the design, including but not limited to, switchgear installation, protection & control wiring, high voltage apparatus installation, transformer installation, earthing and cable installation.


The final stage of any project includes the testing and commissioning of the installed works prior to energisation. This is as important to Delta HV as our Clients. Delta HV offers an experienced and professional approach to the commissioning phase, to fully meet industry standards and Client requirements. We have DNO and National Grid experienced commissioning engineers, capable of producing commissioning plans, drawing management, and undertaking cold commissioning and testing of complete infrastructure projects.

Earthing System Installation

Earth system installation is of great importance to the safe operation of an earthed network. We offer a complete earth system installation package, from design to testing, including technical advice if required.

M&E Works

Electrical and mechanical services to design and scope which include the supply, installation and commissioning of. Our in-house delivery team are trained to BS7671 17thEdition and we complete all our own in-house tests and inspections:

  • LVAC board
  • Small power and lighting and containment installations to IEE BS7671.
  • Low voltage system – test and inspections
  • Ventilation systems
  • Bonding to main earthing system
  • Lightning protection systems
  • Fire detection and alarm Systems
  • Multicore, LV cables, HV cables and SCADA communication installation, termination and testing including containment
  • Review of designs and development into working drawings ready to issue for construction.

Substation Electrical Design

Our in house design team includes over 15 years of power engineering experience, including:

  • Plant layouts and clearances
  • Earthing system
  • Protection & control
  • Transformers
  • Switchgear
  • Generation system design
  • Cable sizing & route design
  • LV systems
  • Contingency arrangements
  • Outage planning

With our professional team, we offer solutions to the most complex of design issues. We ensure all designs are undertaken in conjunction with our site delivery team, to ensure a safe, practical and cost efficient design solution.