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High Voltage

High Voltage (HV) installations form an integral part of any business with a need to be backed by extensive engineering, project planning and maintenance regimes and  designed according to electrical engineering safety principles. 

 This section gives advice on applying the right technical standards, latest news and updates to ensure you’re fully equipped to understand the complexities when installing these systems.

Standards set the benchmarks for good practice, professionalism and help provide assurance to clients and ensure their expectations are met. They also promote a culture that encourages the delivery of high quality services.

Applying the right standards is crucial when carrying out different areas of work; importantly they fulfil obligations under contract but ultimately obligations under Health and Safety and the Electricity at Work Regulations.

When designing, installing, commissioning, testing, inspecting or maintaining high voltage electrical systemsdepending on the scope of work, a combination of the most recent edition of the following Regulations, standards and guidance would apply:

BS 7671 Requirements for Electrical Installations. (The IET Wiring Regulations)

BS 6626 Maintenance of electrical switchgear and controlgear for voltages above 1 kV and up to and including 36 kV. Code of practice

BS EN 50110-1 Operation of electrical installations. General requirements

BS EN 60076-1: 2011 Power Transformers

BS EN 50522: 2011 Earthing of Power Installations Exceeding 1kV

BS 7430: 2011 CoP for Protective Earthing of Electrical Installations

BS EN 61936-1: 2010 Power installations exceeding 1kV part 1 common rules

HSR 25 Guidance on The Electricity at Work Regulations 1989

HSG230 Keeping Electrical Switchgear Safe

HSG47 Avoiding Dangers from Underground Services

SI 2002 No. 2665 The Electricity Safety, Quality and Continuity Regulations 2002

Guidance on the Electricity Safety, Quality and Continuity Regulations 2002

To see the full range of application guides - go to the Application Guides web page

To see the full range of guidance notes - go to the Guidance note web page

To see the full range of editable certificates - go to the Editable Certificates webpage​

To see the full range of technical bulletins - go to the Technical Bulletins web page

For general enquiries contact the Energy Networks Association (ENA) at info@energynetworks.org

AM18.1 Medium Voltage Distributions: Method

ENA databases and portals

The above link provides access to the Document Catalogue, the Type Test Register (of assessed protection devices and invertors for connections) and the EV / Heat Pump database.

ENA access to set of Model Distribution Safety Rules

Electrical Services Health Technical Memorandum 06-03: Electrical safety guidance for high voltage systems

The Dept of Health’s guidance which includes every aspect of HV work 

HSE Safety Notice : Investigation into an explosion of a HV circuit breaker

Keeping electrical switchgear safe 

Electrical switchgear safety: A guide for owners and users