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.

Delta HV has dedicated teams of Power Installation specialists working nationwide fitting out electrical substations, compounds, control rooms, and cable runs.


We deliver, offload, manoeuvre into position and install all Medium & High Voltage equipment, switchgear from 6.6kV, 11kV, 22kV and 33kV, RTU’s, Battery Systems, Power Transformers and associated HV, LV, and control cabling, and much more


As part of any installation process, Delta HV will undertake any specialist lifts or plant movement activities, ensuring any logistical solutions are performed in a safe and efficient manner, ensuring your project is delivered successfully. We have a team of trained switchgear installers, with years of experience in switchgear installation in a variety of different switchgear manufacturer types. We have teams of substation electricians who will install cable management systems relevant to the site environment and specifications, into which the team will install all of your power, control, and fibre cabling.


  • Solar Installations – This can be removed from this site now we have the other pages being added
  • Protection Panel Build – Rename to “Protection & Relay Panel Manufacture”
Delta HV can provide standard 19” rack-type panels in addition to custom-sized panels. These can be tailored to suit specific demands. Cubicles can be supplied in a rear access design and also a front access swing frame style where substation space is limited. All panels can be provided with or without glazed front doors depending upon the required ingress protection rating (IP rating). Protection panels generally have:
  • Relays, selector switches, and test links/MCBs on the front
  • Power supplies, auxiliary relays, and dropping resistors mounted internally
  • Terminal rails where all the externally connected wiring is wired out
High Voltage Cable Jointing
We specialise in providing High Voltage Cable Jointing services. We offer this from LOW VOLTAGE to high voltage cables up to 33kV and also Fibre Optic cables.


Jointing and Terminating Services
We carry out standard techniques for high voltage cable jointing, from the traditional paper insulated lead-covered cable PILCSWA, PILCSTA, MIND type cables through to the modern XLPE and EPR triplex cables, both screened and armoured. Our teams are trained to current up-to-date technologies such as cold shrink, heat shrink, cold applied, products from various manufacturers, including  Reychem,  Prysmiam, Tyco, Euromold, Coopers, karl phisterer and ‘lovink’ joints and terminations. Our highly experienced engineering teams of skilled jointers perform installation services for private networks on behalf of wind farm developers, solar farm developers, oil, gas, chemical, petrochemical, and other heavy engineering and construction industries.


Cable Installation
We provide Cable Installation services through our installation teams who are equipped to carry out the erection and installation of cable support structures for high voltage projects, covering cable pulling, containment, installation, and terminating
Specialising in providing High Voltage  Maintenance services to private networks on more than 300 sites throughout the UK on a 24/7 call-out response basis.


We undertake remedial works (repairs) identified during planned inspection works as well as asset replacement and new installation works. Utilising our directly employed staff, which comprises experienced and knowledgeable Senior Authorised 11kV to 132kV engineers, within a diverse and highly skilled workforce, Delta HV has the capabilities to ensure that any contract is successfully managed, serviced, and delivered to the client’s standards.


Regular inspection and maintenance of electrical systems are essential for ensuring that equipment remains in a safe, good, and operational working order, which will reduce the potential of unplanned shutdowns and increase production/ productivity. We provide a cost-effective maintenance (intrusive, non-intrusive, and preventive) package to bring your system to safe working order and in line with manufacturers’ guidelines.


We also take samples and test systems and report on possible issues and potential solutions to pending problems.
Delta HV specialises in services to the Electrical Distribution Industry. Our team is highly experienced professionals, all of whom have gained an extensive working knowledge in the Electrical Distribution Industry over many years. We provide civil, structural, quantity surveying, contract administration, and clerk of works services to help our clients achieve and deliver effective, best value investment in their operational infrastructure.
  •  Civil design including feasibility studies, CDM designer duties, Civil engineering design works, and planning application drawings/submissions
  • Structural engineering includes building and structure surveys and condition reports, structural calculations/design, and structural detailing
  • Quantity surveying including feasibility studies
  • Project Management of civil contractors on site
  • Clerk of works including quality, health and safety, and environmental monitoring and reporting
  • Safety standby person duties