Edward Dewhurst Ltd  
Over 120 years of Services Engineering.
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Medium Voltage Services
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Edward Dewhurst Ltd have a long history of work in the MV field starting in the early 1970’s with the design, manufacture and installation of neutral earthing resistors for MV distribution networks.

This work led naturally into check synchronizing of MV turbo alternators, these being predominately in the paper and process industry.

In tandem with our clients changing requirements ED Ltd are now heavily committed to the design, installation and testing of MV infrastructures. Our breadth of experience covers extensive works in the laying of ‘Triplex’ and multi-core MV cables at 11kV, MV switchboards for leading British military equipment suppliers and many other companies.

Works also include the supply and installation of transformers and full sub stations from 11kV to the point of use on the LV network. In addition to our design and installation services we also provide testing capabilities. These include the full spectrum of protective systems, from proving the integrity of an installation through to final commissioning. In addition to this we have operational experience of the installation and commissioning of fibre optic communications within a protective hierarchy.

As the companies MV work has expanded, it has been necessary to provide our clients with maintenance back up facilities. This again covers the full spectrum of our installation works.

Foremost in our thinking we have recognised our customers’ needs to keep down time and the associated disturbance to their businesses to an “absolute minimum”.

To assist this aim of “minimum downtime”, we are continually developing our package of non-intrusive testing techniques.

ED Ltd also offer Airfield services which for those less familiar with this area of electrical engineering covers the field of constant current networks as against the more common constant potential systems. The constant current networks with their variable potential structures 600V to 5kV have again given a greater depth to the services available from ED Ltd.


Lancashire Teaching Hospitals NHS Trust.
University of Morecambe Bay NHS Trust.
BAE Systems
Blackpool & Fylde College
Virgin Media
Peel Airports
British Airports Authority (BAA)