Engineers Ireland has created a ‘Practice Note’ to brief and guide engineers involved with high-voltage systems to be aware of the correct standards and controls that they should adhere to.

In May 2022, Engineers Ireland Electrical Division working group published an issues paper  highlighting:

  1. Widespread non-compliance with SHAWW General Application Regulations 76 and 88.
  2. Absence of national recognition of IS EN 61936-1 and IS EN 50110-1.
  3. Absence of a national regulatory scheme for HV installations, works, operations, competence, owners and contractors.  

“The Engineers Ireland issues paper on competence of persons controlling, operating and working on HV apparatus, highlighted that Ireland is not following current European best practice in regard to safe management and operation of HV installations," commented Padraig Plunkett, a member of Engineers Ireland's Electrical Division and management consultant with Kilbride Power.

"The issues paper describes best practice in Appendix 4 and recommends that IS EN 61936-1 and IS EN 50110-1 be used to ensure compliance with SHAWW Act and General Applications Regulations Part 3 Electricity. The HSA have now updated their website to include this advice.

“Section 15 of the SHAWW Act and associated sections and regulations require a person who has control to any extent of a place of work to keep that place of work safe and prevent danger," he added.

"This Practice Note is therefore potentially relevant to everybody and certainly installations owners, installation managers, electrical engineers; power system engineers; mechanical engineers; civil engineers; occupational health staff; environmental engineers; fire protection engineers; risk management staff; project managers and any person supervising or controlling work. 

“There have been a number of accidents in recent years where Irish technicians have suffered life changing injuries as a result of getting too close to live HV conductors. These accidents are totally preventable by strict compliance with IS EN 61936-1 and IS EN 50110-1 and so should not be tolerated. Fast-track building of HV infrastructure in a reckless and unsafe manner can never be justified, even where it is required to reduce global warming,” said Plunkett. 

Historically in this country, high-voltage systems have been managed by a small number of specialist organisations; as Ireland progresses its electrifications of sectors like heat and transport, along with additional growth, more players are operating high-voltage systems.

Engineers Ireland Director General Damien Owens added: "The current requirements for high-voltage systems require review and consideration of some subtle differences between low- and high-voltage systems. Engineers Ireland is in discussion with the HSA, CRU and the environment department, providing our expert opinion on the topic. We will continue this discussion and seek appropriate regulation updates on our members’ behalf."

Guidance for engineers and non-engineers working on high-voltage systems

The practice note is intended as guidance for engineers and non-engineers working on the design, installation and maintenance of high-voltage systems. The safe and reliable operation of high-voltage apparatus is critical in ensuring the smooth functioning of power systems.

High-voltage systems can be dangerous, and failures or mistakes can result in severe consequences, including injury or loss of life, damage to equipment, and downtime. Therefore, it is crucial to have competent individuals capable of designing, operating, and maintaining high-voltage apparatus.

“The practice note covers various topics, including the knowledge, skills, and qualifications needed to work on high-voltage equipment safely," said Owens. "The importance of competence cannot be overstated regarding high voltage apparatus. It is essential that workers understand the risks associated with their work and are capable of identifying and mitigating potential hazards.

“Until the regulations are updated, we hope this practice note will serve as a valuable resource for employers, employees, and other stakeholders involved in high-voltage apparatus operation and maintenance. By following the guidelines in this note, organisations can ensure that they have a competent and safe workforce, reducing the risk of incidents and promoting a safety culture.”

Practice note 

As Ireland continues growing its high-voltage (HV) network to meet demand and support future electrification of heat and transport, correct management, and operation of high-voltage systems by competent people will become a more prevalent requirement.

High-voltage systems are integral to modern electrical power transmission and distribution networks, providing efficient and cost-effective energy delivery over long distances. However, they also present significant challenges and potential hazards to human safety, equipment reliability, and environmental protection.

High-voltage systems’ design, operation, and maintenance require specialised knowledge, skills, and resources to ensure safe and reliable performance.

Historically, experts in EirGrid, the Transmission System Operator (TSO) and ESB, and the Distribution System Operator (DSO), have provided this level of knowledge in Ireland.

However, as new players such as renewable energy generators, data centres and large manufacturing centres develop here, the responsibility is being handed over to potentially less experienced professionals.

In this context, understanding the issues of high-voltage systems and guidance is crucial for professionals and stakeholders involved. This practice note aims to provide an overview of some key issues associated with high-voltage systems, including safety risks, current regulations, and additional regulatory compliance.

High-voltage: Definition

High-voltage is defined by IEC and CENELEC standards as an electrical voltage higher than 1000 V, which includes all voltages on the distribution and transmission networks from 10kV to 400 kV.

In the context of electrical power transmission and distribution, HV is necessary for efficient power transmission over long distances, as higher voltages allow for lower current levels and reduced energy losses. However, high-voltage presents a particular danger to humans with the associated risk of death or life-changing injury from electrical shock, burns and trauma.

For this reason, particular safety precautions and protective measures, as detailed in the applicable international standards listed below, are necessary when working with or around high-voltage equipment.

High voltage dangers

  1. Contact with live HV conductor: when a person comes in contact with or too close to high-voltage, the resulting arc-flash causes severe burns, trauma and electrical current to pass through the body, leading to muscle contractions, and organ damage.
  2. Faults on the HV network: high-voltage faults result in potentially high fault currents, which can result in injury or death from electric shock and arc-flash.
  3. Induction: high-voltages can be induced on adjacent isolated conductors resulting in injury or death from electric shock and arc-flash.
  4. Failure of electrical equipment: failure of high-voltage equipment results in a high-energy explosion, causing catastrophic damage to the equipment, including the production of extremely explosive force, hot gasses, molten metal and shrapnel with the associated risk of death or life-changing injury to any person in close proximity.

Preventing dangers

To prevent these dangers, it is essential to take the mitigation measures detailed in the applicable international standards, including:

  • Verification of design and construction
  • Detailed planning
  • Risk assessment
  • Control of access
  • Management and execution by competent persons
  • Use of appropriate tools and protective equipment.

Lacuna of guidance

Upon reviewing the current regulations and certificates, Engineers Ireland believes that the focus is on low-voltage installations with reference to ET101, National Rules for Electrical Installations, which is now superseded by IS 10101:2020, and there is a lacuna of guidance on high-voltage installations.

Therefore, to ensure owners of and persons working on or near high-voltage electrical installations can carry out their duties described in the Safety Health & Welfare at Work Act 2005 regarding the prevention of danger from electricity, Engineers Ireland members are advised to ensure insofar as is reasonably practicable and within their control, that:

  1. High-voltage installation owners and operators (including the TSO and DSO) only energise high-voltage installations, which a suitably competent person has confirmed as being compliant with IS EN 61936-1.
  2. Contractors delivering high-voltage works have a nominated person employed or engaged as a consultant with the necessary competence to confirm high-voltage works as compliant with IS EN 61936-1.
  3. High-voltage installations owners comply with IS EN 50110-1, including appointing an installation manager and providing Electrical Safety Rules and organisation, as required by clauses 3.2.1 and 4.3.1 of IS EN 50110-1.
  4. Operations and work on or near high-voltage installations are carried out in accordance with IS EN 50110-1 and only on high-voltage installations which are managed in accordance with electrical safety rules by a nominated installation manager.
  5. Contractors and high-voltage installation owners have clear processes in place for the assessment of competence and authorisation of persons managed by a nominated competent person.