FEATURE ARC FLASH
and more importantly, to provide instruction and training to all staff on the impact of electric arc flash. Howarth, who is leading the European
regional branch of the programme continued, “The risk behind the arc flash hazard is really being understood in this organisation now, but the approach to managing the risk varies from country to country. For example, in the US the approach is to provide protective clothing from the beginning whereas in the UK supply of protective clothing is usually the last line of defence. It is these different approaches that are being reviewed, although it is collectively understood that exposing our workers to the risk should be the last resort and this will help mitigate it. The programme has been divided into
two phases - phase one is to carry out thorough technical risk assessments of all equipment and provide an engineering solution wherever possible. Phase two is to provide adequate protection and training if and when needed. After comprehensive full arc flash studies are completed, calculated details of the incident energy release at each point of work will be produced and this can then be reduced or engineered out to reduce risk even further. Existing arc flash personal protective equipment (PPE) will then be supplied to match the incident energy release identified from the study.
THE FULL PROTECTION PACKAGE Due to the complexities of this hazard, InterGen called in local manufacturer and distributor J & K Ross, who has developed, in conjunction with safety specialists DuPont, ARCBAN, a range of arc flash protection clothing incorporating Nomex. The clothing is teamed with specialist gloves and head protection to provide the complete protection package. The approach recommended by J&K Ross is to ‘layer’ garments as opposed to using heavy, bulky single layers to achieve the level of protection required. Combining varying layers of clothing will achieve increased levels of protection and can be added to or reduced depending on the level of protection required. However, whatever layering is chosen, it is important that the clothing selected to work together has been tested to work together and that it is also worn over flame resistant undergarments. Sophisticated protection such as this can only be successful if a full risk assessment has been done and this is the work being carried out during phase one of the Arc Flash Mitigation Programme. Howarth explained, “During phase one
we have provided the highest level of personal protection until we have
30 MARCH 2014 | ELECTRICAL ENGINEERING / ELECTRICALENGINEERING
thoroughly analysed the risk and J&K Ross has supplied its 40cal/cm2
suit,
including hood and gloves. It has taken time and education for our workers to comprehend the potential severity of the arc flash hazard but now they are keen to be provided with the correct clothing.” Thus far the partnership has been a success and InterGen has been reassured with the knowledge and support that the organisation has received from JK Ross. The workers are also very willing to wear
Left: electric arc flash or electrical flashover is one of the most deadly and least understood hazards of electricity
the specialist clothing because it is comfortable and surprisingly doesn’t restrict movement too much. Team that with the education they have received from the manufacturer and their understanding of the risk of an electric arc flash has reiterated the importance of wearing suitable protective clothing. “The range of clothing supplied is of a
very high quality”, Howarth added, “and it is exceptionally good value for money. Once our assessments are complete it may be appropriate to provide slightly different clothing (the layering approach as they recommend) that has minimum restriction for the worker but still provides adequate protection against the hazard.”
SUMMARY There is still much work to be done to complete this thorough review programme but the results from it will ensure that, not only are the maintenance workers with InterGen going to be some of the most protected workers in this type of industry, but they will have an increased respect for the dangers of working with electricity too.
J & K Ross
www.arcflashprotection.co.uk T: 01925 645 645
Enter 217 Arc flash protection: putting PPE last
J & K Ross also explained that although personal protective equipment (PPE) is an important consideration in electric arc flash protection, it should come last in the hierarchy of control measures that need to be undertaken to ensure employee safety. Usually caused by inadvertent contact between an energised conductor, such as a busbar or wire with
another conductor or an earthed surface, arc flash happens when a short circuit current melts the conductors, ionises the air and creates a conducting plasma fireball which can reach temperatures of 20,000°C or more. The most common causes of arc flash are accidentally bridged contacts on energised equipment
such as switchgear, from tools dropped during maintenance work, or the use of substandard electrical test equipment. Often companies will look to PPE as the first line of defence when protecting workers against the risks
of electric arc flash. However, Chris Ross of J&K Ross, pointed out that the use of PPE should actually be one of the last steps taken to manage electric arc risks. He said, “PPE should be the last line of defence. The most important thing to do is a risk assessment for electrical safety. This should include the risk of electrocution as well as damage and injury from electrical arc flash. It is important, legislatively, in the UK and Europe to ensure that risk assessments are carried out and that the risk of arc flash hazard is minimised, where possible. The main piece of legislation surrounding risk assessment for end users for all hazards is the EU
Directive 89/391 (EU Workplace Health and Safety Directive). Commenting on this legislation Ross added, “Although there is no direct legislative requirement to conduct an arc flash study, over and beyond the risk assessment process, the risk assessment process does require you to quantify the risk. The only way you can do this is by actually undertaking an arc flash study. The risk needs to be quantified before you can control it and then you can move on to take preventative measures to protect personnel before deciding on the level of PPE required.” The European Agency for Safety and Health at Work defines risk assessment as the process of
evaluating risks to worker’s safety and health from workplace hazards. It is a systematic examination of all aspects of work that considers what could cause injury or harm - whether the hazards could be eliminated and, if not, what preventative or protective measures are, or should be in place to control and mitigate the risks. Ross believes it is necessary to go further and advises the adoption of the step by step approach of ‘Predict, Prevent, Protect and Publish’ from DuPont.
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