Hornbill offers a complete high voltage (HV) specialist installation, maintenance and support service throughout the UK. All of our HV engineers are highly qualified, experienced and hold National Grid and Basic Electrical Safety Certificates (BESC). We can offer assistance on small to full turnkey projects, such as professional services for the generation and distribution networks, including private sites.

Transformer installation, maintenance, testing and repair

Hornbill can install, maintain and test all transformers, from small to large generation transformers and bushings. We can also supply and install monitoring and protection equipment and anti-condensation equipment, including breathers.

Our oil filtration equipment capabilities include oil replacement and diagnosis (including onsite PCB testing). We also carry out tap changer, selector and diverter maintenance and repairs. Our services also include the supply and installation of on-line transformer gas analysers.

Switchgear and circuit breakers

Hornbill can carry out full installation, testing and repair of LV and HV switchgear, as well as MCC design and manufacture. We offer full maintenance and testing of circuit breakers up to 400kV, and can carry out annual inspections including circuit breaker timing tests and condition analysis.

Installation, maintenance and repair of tap changes and diverters, which can be carried out on site or at our inspection and testing facility in Llandarcy, Neath.
Hornbill is qualified in the erection, installation and pre-commissioning testing of generator transformers up to 750MVA, step-up transformers and the transmission of electrical power into the National Grid substation.
Hornbill is experienced in the positioning and installation of liquid-filled bushing and substation equipment up to 400kV, including linking the direct feed into the National Grid substation.
We are specialists in all areas of substation high voltage such as installation, cabling, testing and commissioning, maintenance, switching, cable fault finding and cable spiking.
Hornbill provides a complete package in the positioning and construction of transformers such as three-phase liquid-filled power transformers and feeding back into client BOP supplies.

Cable jointing and terminating

Our cable jointing and terminating services include:

  • Testing at DC or very low frequency (VLF)
  • Phasing out on dry and live systems
  • Indoor and outdoor cable terminations of heat shrink and cold fit
  • Fault locating and cable spiking

Substations, switchyards and SAP service

Hornbill performs installation, maintenance, testing and repairs to open busbar earth switches, surge arrestors and isolators (including retrofits). We also carry out circuit breaker installation, testing and repair (including SF6 condition assessment and replacement). Hornbill has multiple senior authorised persons (SAPs) up to 33kV.

Protection and monitoring equipment

We offer a range of protection and monitoring services, which include:

  • Design, installation and testing of complete protection systems
  • Testing by primary and secondary injection
  • Relay annual trip testing and fault diagnosis

ISO-certified high voltage specialists

Hornbill is committed to quality, health and safety and our environmental impact. Therefore, we have been certified with ISO9001, ISO14001 and OHSAS18001 accreditations. Hornbill is also an Investor in People registered company.