Arc Flash Clothing & Protection For Safe Windfarm & Wind Turbine Working
Published 22 Nov 2018
uploaded by Chris Dodds - Thorne & Derrick Sales & Marketing Manager
Arc flash accidents are not nearly as rare as you would think and the hazards they create are severe. In wind turbines, these hazards are magnified.
Installing and maintaining wind turbines can be a tricky job and it is important to understand the importance of staying safe and Protecting Lives by wearing arc flash clothing including an arc flash helmet, insulating boots and arc flash gloves.
In fact, most employers wouldn’t dream of permitting their teams on site without adequate protection and workers themselves are more than clued up when it comes to the latest electrical safety equipment requirements.
However, the same can’t be said when it comes to the potentially fatal risk posed by an Arc Flash – a relatively misunderstood, but extremely common type of electrical explosion facing those working on onshore or offshore, private or commercial wind turbine projects.
Arc Myth Busted: Did you know most arc flash accidents occur in LV systems?
Especially legacy switchgear and switchboards undergoing the The Three R’s – retrofit, refurbishment or repair. Modern technology Low, Medium & High Voltage Electrical Equipment with integral insulated arc-free busbar assemblies, arc flash relays and arc quenching switchgear, such as manufactured by Eaton, minimises but does not eliminate the risk of arc flash completely.
Of course, the best way to avoid arc flash is to de-energise – nevertheless, Arc Flash can occur on power systems inadvertently made live while undergoing maintenance under planned isolation procedures.
A Wind Turbine Arc Flash Incident
The Clear & Present Danger
Although no injuries were reported – thankfully – the devastation inflicted to the wind turbine pictured below is extreme, to the point of destruction. That turbine is beyond repair.
Now imagine just for a moment if the wind turbine had been manned or the incident had involved manpower – the feasibility of providing urgent medical treatment to an injured worker in a nacelle at high level is complicated. Often, the physical workplace location of the wind turbine prevents rapid rescue and emergency intervention due to remoteness and accessibility – quite often offshore. By September 2018, the UK wind power sector consisted of 9,088 wind turbines with a total installed capacity of over 20.1 gigawatts: 12,222 megawatts of onshore capacity and 7,907 megawatts of offshore capacity.
Technicians from Vestas, the company that oversees the maintenance of the turbine, attended site in April 2018 to complete a damage assessment. An expert from the company, who specialises in examining wind turbines that have experienced major malfunctions and fires, began an investigation into how the fire occurred.
An engineer hired as part of the insurance claim eligibility process was able to look at the wind turbine and investigate the cause of the fire. According to the engineer’s findings, the turbine experienced an arc flash that caused an electrical fire.
Officials with Vestas have declared the nacelle a total loss, though the tower and foundation are reusable, and will be providing the client with the costs for options ranging from decommissioning of the wind turbine to replacement of the unit.
Clean-up at the site to remove the damaged nacelle occured over the summer but is not expected to be completed before the end of the year.
So don’t ignore The Arc – a few attributable costs of arc flash induced outages and downtime:
- Revenue loss incurred from inability to generate electricity. £100K’s-ish. Minimum.
- Outage period until repairs are complete. Weeks? Months??
- Replacement of damaged or destroyed equipment. Financially, don’t think about it.
- Consequential reputation damage. Immeasurable.
What Is An Arc Flash?
Hotter than the sun (around 20,000°C) and louder than a bullet, an Arc Flash is when an arcing fault releases dangerous levels of radiant energy, which vaporises metal that spews from the arc. The air is super-heated causing pressure waves that can propel individuals across rooms and create a deadly molten shrapnel.
It goes without saying; the extreme temperatures of an Arc Flash can burn clothing and human skin within fractions of a second, even if the operative is situated five or six metres away from the Arc Flash event. It can also result in an explosive pressure wave that can throw workers across the room and a sound blast that can rupture eardrums.
An Arc Flash event is also accompanied by a bright flash which can cause temporary or even permanent blindness.
Treatment for those that survive an incident can require years of skin grafts, hospital stays and rehabilitation – they may never recover sufficiently to regain their lifestyle, so it’s safe to say that choosing the appropriate PPE is key when it comes to Arc Flash safety.
Posing A Risk
Electrical in nature, Arc Flash poses a substantial risk to those working in the wind industry which is constantly growing in importance due to its potential to contribute significantly to our national energy needs.
When working on wind turbines or windfarms, Arc Flash incidents can occur in both low voltage environments as well as high voltage, with particular reference to the following incidents…
- Opening energised electrical cabinets and verifying zero energy (testing dead)
- Securing and removing lock out and tag out (LOTO) devices
- Conducting trouble shooting on energised equipment and parts
- Working on near or exposed live conductors
- Breaking ground to install turbines
It is worth noting that the above incidents are of broadly the same severity whether the turbine is part of a large commercial windfarm or one of the growing number of small scale turbines installed by businesses.
How To Protect Yourself Against Arc Flash
Enhanced and effective arc flash protection is safely achieved by wearing layers of protective clothing and garments manufactured from inherent fibres and which feature specific Arc Flash resilient components. Without the correct high-quality garments, arc protection levels will be compromised.
In addition to quality, it’s important to consider the longevity of the garment – depending on how it’s manufactured it may lose its effectiveness. Always look for products that feature Arc Flash protective qualities in the thread, as opposed to just a sprayed material, which will lose its impact over time.
PROGARM THE ARC FLASH SPECIALISTS
ProGARM are the leading UK manufacturer of high quality Arc Flash Clothing, Garments & Workwear – we work successfully with them Protecting Lives.
Thorne & Derrick are leading Specialist Distributors & Stockists of LV, MV & HV Cable Installation, Jointing, Substation & Electrical Equipment to the wind industry.
Thorne & Derrick Powering The Wind Industry
T&D are Specialist Distributors to the UK and international Offshore Wind industry to provide safe and reliable LV HV Electrical Cable & Power Distribution Systems – we are highly customer responsive and absolutely committed to providing a world-class service. We provide expert technical support and supply from a multi-million pound stock holding:
Cable Joints, Terminations & Connectors
Earthing & Lightning Protection
Cable Accessories – Lugs, Glands
Circuit Protection & Fuses
Cable Cleats & Clamps
Electrical Safety Equipment
Cable Pulling & Laying Equipment
Arc Flash Protection & Clothing
Cable Duct Seals & Cable Transit Systems
Surge Arresters & Bushings
We have a UK Distribution Agreement with Nexans Power & Euromold Cable Accessories UK to supply their Heat Shrink and Cold Applied Slip-on ranges of 11kV/33kV/66kV joints and terminations and Euromold brand of separable connectors. Since 1985, we have established an international reputation based on Service, Integrity and Trust – contact us.