Health and Safety Executive issues safety notice regarding the lubrication of circuit breakers

The incorrect use and application of lubrication on HV and LV circuit breakers resulting in mal-operation and increased risk of catastrophic failure and downstream fire. Duty-holders and Specialist Electrical Contractors should ensure that their maintenance procedures associated with cleaning and lubrication of HV and LV circuit breakers meet with the requirements defined in HSG 230[3], BS 6423[4], BS 6626[5], BS 6867[6] and as prescribed in the manufacturer’s instructions. In particular, the maintenance procedure should ensure that the manufacturer instructions on cleaning and lubrication of the circuit breaker mechanism are followed at appropriate intervals, including the selection and application of the correctly specified lubricants (products) for the task.

Investigation into an explosion of a HV circuit breaker indicated that recently carried out maintenance may have been a causal factor. The incident resulted in catastrophic failure of the HV circuit breaker leading to fire / explosion and could have resulted in fatal injuries. Maintenance of HV and LV circuit breakers typically involves both the cleaning and lubricating of the operating mechanism. The HSE investigation found that the same physical product was used for both maintenance activities, but evidence shows the product was in fact only suitable for cleaning and NOT lubrication. This situation may have arisen because of the availability of different products, (for different purposes), within the same product range, or changes to the products composition over time whilst retaining the original name. It is essential that the correct product is used for each task.

Photograph of the HV oil circuit breaker taken after the catastrophic failure, which resulted in fire and explosion within the substation – Image via HSE

HV and LV circuit breaker mechanisms are required to operate at high speed to disconnect electrical faults with a high degree of reliability from the associated electrical system. To ensure the required performance is retained it is vital that the circuit breaker operating mechanisms are functionally checked and maintained periodically as per the requirements defined in relevant good practice HSG230[3], BS 6423[4], BS 6626[5] and, BS 6867[6] and as prescribed in the original manufacturer’s instructions.

If during functional testing (including circuit breaker timing tests) or during periodic planned preventative maintenance it is observed that the mechanism is slow to operate, it is good practice to relubricate the mechanism, adhering to the recommendations given in the manufacturer’s instructions. During the planning stage, this will involve identifying the correct type of lubrication to be applied to different parts of the mechanism and how it should be applied. In extreme cases, where the circuit breaker mechanisms are observed to be sticking due to old, congealed lubricant, it is common practice to apply a cleaning product to remove this prior to re-lubrication. Care should be taken to ensure that the cleaning products are compatible with the circuit breaker following the recommended procedure given in the manufacturer’s instructions before reapplying the manufacturer recommended lubricants.

It should be common knowledge in the switchgear industry that the incorrect use and application of lubrication has been a major cause of maloperation in switchgear and can lead to very serious consequences. However, observations made during several recent routine planned inspections relating to the maintenance of circuit breakers together with the findings from a recent HSE investigation – where an employee marginally escaped serious personal injury when an HV circuit catastrophically failed – has highlighted that this information may no longer be common knowledge. HSE routine inspections and investigation found evidence that some HV and LV specialist electrical maintenance contractors and end users commonly use aerosol based multi-purpose lubricants for BOTH cleaning and relubrication tasks.

The recent HSE investigation into the failed HV circuit breaker concluded that ‘stiction’ in the failed circuit breaker may have been a result of an incorrect aerosol based multipurpose lubricant being applied to the circuit breaker mechanism. This happened even though the circuit breaker had been maintained less than three months prior to the incident and was reported to be operating satisfactorily. Independent forensic analysis work conducted during the investigation showed that the multipurpose lubricant used during the maintenance of the failed circuit breaker prior to the incident, evaporated by 75% of its original weight within 2 weeks of application. The analysis concluded that for this reason, multipurpose lubricants containing solvents (e.g. white spirit) are unsuitable for use as a lubricant of this type of HV and LV switchgear.

In addition, historical research by other organisations recommended that hydrocarbon sprays or solvents should NOT be used on circuit breaker mechanisms.

You can read the full safety notice here – https://www.hse.gov.uk/safetybulletins/lubrication-circuit-breakers.htm

Wiring Matters – Issue 87 – September 2021

It’s that time again, here is what you can find in Issue 87 (September 2021) of the IET’s Wiring Matters magazine.

Evaluation and metrics

The design framework of IEC 60364-8-1 provides guidance on a more energy-efficient electrical installation through careful placement of electrical supplies, considered infrastructure design, controls and energy management. All of this is designed to minimise energy loss in the distribution of electricity and reduce energy consumption at the point of use in the electrical installation, whilst still maintaining a suitable and comfortable environment for the end-users.

Electrical Safety Standards in the Private Rented Sector

The IET’s Technical Helpline continues to be inundated with queries relating to the practicalities of implementing the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020 (ESSPRS). These place legal requirements on landlords to ensure that every electrical installation in a privately rented residential premise is inspected and tested at intervals of no more than 5 years, by an electrically qualified and competent person.

Myth Busters #7 – Out with the old, in with the new?

The introduction of the 18th Edition of the IET Wiring Regulations (BS 7671:2018) saw a new regulation buried in Section 536 Co-ordination of electrical equipment for protection, isolation, switching and control.

Back to the Forum – Current-carrying capacity of cables buried in the ground

A question that arises periodically on the IET Engineering Communities forum concerns the current-carrying capacity of cables buried in the ground, in particular, the data used to select the appropriate cross-sectional area (CSA) of live conductors.

TT earthing considerations

TT earthing facilities are installed when the distributor does not provide a TN earthing system or when circumstances dictate that a TN earthing system cannot be used. A look at the considerations and what you need to know.

You can take a look at the full edition via the link below –

https://electrical.theiet.org/wiring-matters/years/2021/87-september-2021/

Next phase of government project to map the UK’s underground pipes and cables launched

The Government launched the next phase in the building of a digital map of underground pipes and cables today, as the country moves a step closer to revolutionising construction and development in the UK.

The National Underground Asset Register (NUAR), is now entering the Build Phase of the project. Cabinet Office Minister, Lord True CBE, and Mayor of Tees Valley, Ben Houchen, visited industry representatives and asset owners in Darlington for the launch to discuss the current challenges that NUAR will help address.

Over four million holes are dug in the UK each year, many in the wrong place. The economic cost of accidental utility damage is around £2.4 billion each year. Unforeseen ground conditions are a major obstacle to all construction and housing projects, especially on previously developed land. The new digital map of underground pipes and cables will help improve efficiencies in construction and development, reduce disruption and improve workers’ safety.

NUAR forms part of the Government’s efforts to build back better and greener, with tangible benefits, and speed up the delivery of housing and infrastructure projects from design to build. Fast access to this data will save utilities companies and local authorities time and money, and reduce the disruption caused in trying to fix leaks and put in new infrastructure.

Lord True CBE, Minister of State at the Cabinet Office, said:

I am delighted to launch the build phase of the UK’s new National Underground Asset Register. This new digital map of the UK’s underground utilities assets demonstrates our commitment to putting innovation at the forefront of the UK’s economic recovery and ambition to Build Back Better.

The digital map will be built in partnership between industry and government over the next three years, starting in the North East of England, Wales and London. The platform will enable critical and local services, such as gas, water, electricity and telecommunications, to be efficiently maintained and delivered to homes and businesses via the web of cables, pipes and ducts currently beneath our streets.

As the UK government continues to work with local partners in the North East of England on a number of projects, it further demonstrates the integral role the region is playing in utilising the expertise available in all corners of the UK and building on the nation’s levelling up agenda.

Nigel Clifford, Deputy Chair of the Geospatial Commission, said:

Unlocking value from geospatial data is the heart of the UK’s Geospatial Strategy. Our National Underground Asset Register will be a momentous step towards providing the UK with a shared national data asset of significant value. I am proud of the collaboration with industry that we have so far established as part of our preparatory work and look forward to it continuing.

Ben Houchen, Mayor of Tees Valley, said:

I am absolutely delighted that this innovative new map of what lies beneath our feet is being launched and rolled out in Teesside. This new service will mean less mistakes are made when digging holes and less disruption to local people. Across Teesside, Darlington and Hartlepool we’re making huge strides; we are transforming northern Europe’s biggest brownfield at Teesworks creating thousands of jobs and transforming our economy to a greener future, and this new map will be incredibly helpful.

If you have any questions about the project, and in particular if you are an owner or operator of buried assets, please get in touch via [email protected].

Next generation of heat networks to power UK’s green revolution

Homes and businesses will be made greener as low-carbon energy is today placed at the heart of the latest round of funding for heat network projects across England.

The new £270 million Green Heat Network Fund, announced by the government today (Tuesday, 7 September), will only support low-carbon technologies like heat pumps, solar and geothermal energy in the roll out of the next generation of heat networks which will enable more towns and cities to take up this tried and tested technology from 2022.

Heat networks supply heat to buildings from a central source, avoiding the need for households and workplaces to have individual, energy-intensive heating solutions – such as gas boilers. At present, there are over 14,000 heat networks in the UK, providing heating and hot water to around 480,000 consumers.

Heat networks have the potential to be a cost-effective way of reducing carbon emissions from heating. They are the only way that larger-scale renewable and recovered heat sources – like the heat from large rivers and urban recovered heat, such as from the London Underground – can be utilised.

The previous Heat Networks Investment Project (HNIP) has provided more than £165 million of funding for schemes across England and Wales since 2018.

The new Green Heat Network Fund (GHNF) successor scheme will go even further, with applications only being supported if they include low-carbon heat-generating technologies, such as heat pumps, waste heat and energy from geothermal sources.

The successor scheme is set to play a significant role in kick-starting market demand for heat pumps, which will drive down costs for consumers and delivering a mix of low-carbon heating solutions as we incentivise people to gradually transition away from fossil fuel boilers over the next 15 years.

With heat in buildings being one of the largest sources of UK carbon emissions, accounting for 21% of the total, there is an urgent need to deliver a mix of new, low-carbon heating solutions to meet our legally-binding target to end the UK’s contribution to climate change by 2050.

Energy Minister Lord Callanan said:

Finding a mix of innovative solutions to how we heat our homes in the most affordable way is going to be vital as we support people to gradually transition away from gas boilers over the next 15 years.

Today’s announcement shows we are going even further in our goals to expand this tried and tested heat networks technology, making even more use of the likes of recovered heat from the London Underground to heat our homes.

The Green Heat Network Fund will also allow us to drive forward the new, cost-effective and low-carbon technologies we need to kick-start new industries and support new jobs in the low-carbon technology sector as we build back greener from the pandemic.

Although heat networks currently meet approximately 2% of the overall UK demand for heating, the independent Committee on Climate Change (CCC) has estimated that, with continued support, they could provide 18% by 2050 – which is why the government is driving investment through the Green Heat Network Fund.

The Heat Networks Investment Project had focused on accelerating the growth of the heat network market and has permitted fossil fuel sources of heat provided they offer carbon reductions and will be replaced by low-carbon alternatives over time.

However, the successor scheme will incentivise new and existing heat networks in England to move away from high-carbon sources, as well as exploiting waste-heat opportunities while bringing down costs for consumers.

The Green Heat Network Fund is expected to fund the delivery of an estimated 10.3Mt of total carbon savings by 2050 or the equivalent of taking 4.5 million cars in England off the road for a year.

Also being published today is an assessment of the potential for future heat networks to be sited across England, Scotland, Wales and Northern Ireland. The study identifies opportunity areas that could be best-placed to support future heat network projects and how much heat could be supplied by them.

It identifies areas for district heating in each of the four nations separately across the UK by combining heat demand data and potential sources of waste heat to determine where heat networks could be commercially viable.

Thousands of new solar panels are to be installed in UK prisons

Thousands more solar panels are being fitted to prisons across England to help cut carbon emissions and save taxpayers’ money, Prisons Minister Alex Chalk has announced.

The installations are expected to cut more than 1,300 tonnes of carbon from the earth’s atmosphere and provide 20% of each prison’s electricity – a significant saving as the gworks towards its ambitious net-zero target and a move that will save around £800,000 a year.

In total over 16,000 new ground mounted panels will be switched on across the prison estate, with HMPs Bullingdon, Erlestoke and Wayland lighting the way in the next few months and work ongoing to power the remaining 16 from Spring next year.

Prisons and Probation Minister, Alex Chalk, said:

As we build back safer and greener from the pandemic, our prisons are playing their part in the Government’s ambitious environmental plans.

Alongside our wider sustainable action across the estate, including new all-electric prisons, we will ensure our jails are good for the pocket and the planet.

This unprecedented expansion of solar energy follows the announcement in May that the government’s four new prisons – a vital building block in the drive to create 10,000 new modern prisons places that cut crime – will operate as zero-carbon in the future. 

The prisons will use an all-electric design that eliminates the need for gas boilers and will in time produce net-zero emissions.

Solar panels, alongside heat pumps and more efficient lighting systems will reduce energy demand by half and cut carbon emissions by at least 85% compared to prisons already under construction.

The environmentally friendly drive accompanies wider government action to build back greener with more than £12 billion in green investment to help achieve its net zero commitment.

This will include hydrogen and carbon capture technology, greener homes, electric vehicle charging infrastructure, walking and cycling infrastructure, flood defences and backing offshore wind to power every UK home by 2030.

Notes to editors

  • Ground mounted solar panels have recently been installed at HMPs Bullingdon, Erlestoke, and Wayland.
  • Panels are now being installed at HMPs Eastwood Park, Ford, Guys Marsh, Haverigg, Isle of Wight, Leyhill, Lindholme and Moorland, Littlehey, New Hall, and Onley, Stocken, Werrington, Whatton and Whitemoor.
  • Work is ongoing to facilitate panels at HMPs Bure and Full Sutton.
  • The project will cost around £12 million, to be recouped through annual savings. Combined, the prisons will generate more than 7000kW of capacity per year.
  • The first of the four new prisons will be built next to HMP Full Sutton in East Yorkshire and work is underway to investigate locations for a further prison in the North-West of England and two in the South-East.
  • The MOJ is seeking to achieve the gold-standard ‘outstanding’ rating in Building Research Establishment Environmental Assessment Method (BREEAM) for its four new prisons. BREEAM is an independent scheme which assesses the sustainability of infrastructure projects.
  • The UK is a global leader on tackling climate change which is why we’ve committed to reach net zero by 2050.