ATLAS, the Association of Technical Lightning and Access Specialists, has left no stone unturned when it comes to teaching the lightning protection industry about the BS EN 62305 standard

August 2008 marked the official and final implementation of the new British Standard for Lightning Protection, superseding the old BS 6651 standard, but have we all taken notice? As 2010 dawned, it became clear much of the construction industry still has a lot to learn about the standard and its implications.

Colin Clinkard Director from BEST Services said:
‘Although the new standard has taken our industry a quantum leap forward in terms of the level of lightning protection provided, the difficulty now is ensuring the entire construction industry understands and enforces the new standard'.

Many contractors and architects are still requesting quotations from lightning protection specialists based on the old BS 6651 with approximately two thirds clearly still not understanding the new standard. This is both frustrating and inconvenient for Atlas members who find themselves educating prospective clients what BS EN 62305 is all about every time they tender for new business. Much of the problem is the new standard has been too hard to understand.

Chris Ross explains the principle themes to the Arc Flash Protection Programme from J & K  Ross

Electric arc is one of the most deadly and least understood hazards of electricity. The outcome of an arc flash can be disastrous but most people are unsure how to deal with the risks effectively.

An electric arc is an ongoing plasma discharge through normally non-conductive media such as air and occurs when there is a short circuit through the air between conductors or conductors and the ground, resulting in hazards including exposure of workers in front of the electric arc to extremely high temperatures, ultra violet light, toxic smoke and fumes and fast moving debris. This can result in burns, blindness, lung damage, hearing damage and death to not only the people working on the electrical equipment but also to people located nearby. J & K Ross has developed the Arc Flash Protection Programme to help companies assess the potential risks of arc flash, carry out the necessary checks and implement improved procedures if necessary. This may include the implementation of personal protective equipment (PPE).

Risk Assess
People working in the vicinity of or at energised parts of electrical systems need to be protected against the effects of possible electric arcing. All such work needs, first of all, to be subjected to a risk assessment. This will enable the risk from arc flash to be identified, determine who might be harmed and form the foundation of the next steps.

The severity of the thermal effect of an arc flash is defined as incident energy, which may arrive at the worker at a given distance from the electric arc, and is measured in calories/centrementre² (cal/cm²); it is the energy that a victim, at a given distance from the electric arc, could receive to the surface of their clothing. In cases where the clothing is not sufficiently protective against the heat and radiation generated by an electric arc, the victim may suffer serious skin burns. An arc flash study will tell you the incident energy likely to occur due to the flashover, or in simple terms - how big is the bang? Following a risk assessment it may be necessary to carry out an arc flash study to establish the potential incident energy and then suitable risk control measures can be explored. Most importantly, there will be an evaluation that will highlight the cases of low risk, those which will need other protective measures and those areas where there is a great danger to workers who engage in live working activities or are working on or close to energized electrical equipment.

Based on the outcome of the risk assessment and arc flash study, control measures need to be implemented to remove, eliminate or reduce the risk. These measures should adhere to the following hierarchy of risk controls:
1. Elimination- de-energise equipment before beginning work
2. Minimisation - investigate trip times or fuse ratings and explore possibilities for faster disconnection times.
3. Information and training - educate workers to ensure their competence
4. Control the risk - properly maintain equipment and substations to ensure safe working systems
5. PPE - issue as a last line of defence to help prevent burn injury to workers

If it is still necessary to protect workers, providing all other practicable measures have been taken to minimise the risk, adequate PPE should be issued as a last line of defence. PPE can help protect against the thermal effects of an arc flash but it doesn't prevent the accident from happening in the first place.

Flame resistant (FR) clothing can be rated based on its Arc Thermal Performance Value (ATPV) in cal/cm2. To properly protect a worker, the ATPV rating of the FR clothing must exceed the calculated prospective incident energy caused by an arc flash onto the worker at a given distance from the electric arc. J & K Ross, in conjunction with DuPont Personal Protection, has developed ARCBAN® a range of CE certified arc flash protective garments made from Nomex®. The ARCBAN® range of garments are designed to be layered to offer the relevant level of protection when required for different jobs with different possible incident energies and ensure that the worker is not restricted or compromised with cumbersome clothing, which would have been selected based on being appropriate for the worst case situation. Layering the garments can help to increase the ATPV levels due to the air gaps in between the garment layers.  It can also help with matching the hazard and risk with the appropriately designed PPE resulting in the wearer having more fit for purpose and comfortable solutions for the relevant hazardous environment.

The ARCBAN® range incorporates DuPontTM Nomex®, an inherently flame resistant meta-aramid fibre that does not melt, drip or support combustion in the air.  The thermal behaviour of Nomex® is due to its molecular structure and not by applying a flame retardant chemical substance to the fabric, yarn, fibre or polymer. This means that Nomex® offers permanent protection that cannot be washed or worn away.  The ARCBAN® range offers head to toe solutions providing various levels of electric arc protection.

DuPontTM and Nomex® are registered trademarks or trademarks of E.I. du Pont de Nemours and Company or its affiliates.ARCBAN® is a registered trademark of J & K Ross.


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There are many things in life we do without thinking; closing the car door as we get in, buying a lottery ticket every week and, in many a factory, pulling plugs straight out of sockets! Now if it's the kettle plug we pull out before going home that's one thing. If, however, it's a three phase 415VAC equipment plug, then that can be much more risky explains Stephen Thackray of Marechal Electric

For one thing, the 13A kettle socket will be switched and most people would flick the switch first before withdrawing the plug. The industrial wall socket is commonly unswitched, or just with a separate rotary isolator fitted adjacent to the socket. This looks like an after-thought to protect the socket user by providing an isolator nearby and hoping it gets used. It depends on the isolator being operated before the plug is withdrawn from the socket to ensure the circuit is no longer live - hardly a fail-safe solution.

The consequence of pulling industrial plugs live out of sockets can simply result in the required disconnection of the electricity supply, but a much more serious outcome can be severe burning from electrical arcing or molten metal, usually brass - the metal widely used for plug and socket contacts. The fact that often nothing happens to the user when the plug is pulled out can lead to a false sense of security and risks the action becoming routine or entirely normal and, as such, one of those things we don't think about when we do do it. Things can become even more dire if there is a fault in the plugged-in equipment  - perhaps a locked rotor - then the danger of drawing an electric arc with the plug is extremely high. Preventing this outcome should be a corporate priority.

It's all in the design
The common industrial plug and socket design employs a brass pin fitting into a brass tube. Somewhere along this tube the male pin will make contact with the tube although not throughout the entire length of the tube - a forced fit.  The 16 and 32A versions are manageable, but the 63 and 125A versions test the strength and guile of the user.

Some socket versions offer an interlock to prevent live pull-outs but these don't always withstand the physical frustration of the user trying to disconnect the equipment. The common result of repeated plug insertions and withdrawals is contact wear and loosening. Loose contacts lead to overheating which leads to oxidization and eventual failure.

The abuse plugs and sockets seem to attract affects their serviceability. Conductor terminal screws loosen because nothing prevents them from loosening. The culprits are movement, thermal cycling and vibration. The cable entry point into the plug is often inadequate, forcing extra strain onto the conductor terminals themselves whilst the cable gland works loose and migrates up the cable sheath to perform no role whatsoever.

If there is one application where duty holders are sensitive to these failings, it is the transport industry - since refrigerated lorries must (increasingly) plug in overnight to cut down on noise pollution, engine wear and tear and fuel costs. It is common to see 415VAC 32A coupler sockets lying around on the tarmac suffering from the problems listed above but also quite possibly in or close to a pool of water. The RCD-protected socket posts will be at various angles having been reversed into by the trailer. The pin and sleeve design cannot offer a switched coupler socket thus trailers can be unplugged live with all the inherent dangers.

So what's the alternative?
The decontactor socket design approaches the contact problem head-on by using butt contacts instead of force fit types. The concept is it is safer to throw a switch before disconnecting industrial electrical plant and so the decontactor has an integral switch mechanism.  So far it's a plug and socket and a switch. But once the switch mechanism has been operated the isolator element comes into play. A decontactor is then a plug and socket, switch and isolator in one product - all the elements needed for safe electrical work practices.

This 3-in-1 design is made possible by the use of spring-loaded butt contacts. The silver-nickel tipped contacts mate head-on so there is no wear, no forcing of one into the other and disconnected by pressing a socket latch. Conductors are prevented from loosening by an anti-vibration terminal design. Pressing this latch is the only way to release the plug. This is particularly important if an extension lead is used. Holding the plug in one hand and the coupler socket in the other constitutes an ‘across the heart connection'. As the decontactor is a load-break device, the plug is already dead before it can be removed from its socket.

It's the simplicity of design that makes the decontactor such a versatile product giving the user the benefits of flexibility and above all safety on the shop floor.

Flexibility comes from the ability to have previously hard-wired equipment pre-plugged ready for easy re-location to suit production needs, from having equipment isolated quickly and safely by multiskilled staff and from the ability to take single phase supplies from three phase decontactor sockets. Motors fitted with decontactors can be replaced in a fraction of the usual replacement time.

User safety is provided ultimately by the electrical performance of the product. As an example, the 20A rated decontactor was successfully subjected to 10kA withstand and close-on tests - 80A delayed fuse, power factor 0.49 at 480VAC. Because the contacts close onto each other immediately, the current flows and, in the case of closing on a fault, trips the protection (ie. the fuse or circuit breaker).

Each socket contact has its own arc chamber and the socket is fitted with a safety shutter to prevent access to the contacts. As expected, sockets can be padlocked off to provide visible isolation. Most versions offer auxiliary contacts for controls or signals if required.

Reducing risks
Instilling safety procedures into the workforce is a fulltime job. Staff turnover means constant vigilance is required, particularly when the command of English is limited. Cleansing regimes, where required, remain unfriendly to electrical equipment particularly to sockets that are on the front line.

The decontactor, as a supply socket or motor disconnect, offers a much improved level of safety to users, backed up with positive test lab results, compliance to BS EN60309-1 (industrial sockets), BS EN60947-3 (air break switch) standards AC22, AC23 & AC3 and ultimately the Low Voltage Directive.

Our resident grumpy old man, John Houston, this month turns his attention to the general  election

I know by the time this month's diatribe hits your desks the election hullabaloo that has been this most publicly debated of popularity contests will be done and dusted. Personally, I found the alternating public squabbling and sickly patronisation (just in case parliament hung) very entertaining. My fear was a large sector of Joe Public would miss the vital policy points -hence that very nice young man Mr Clegg's immediate rise to prominence following the first debate.

What alarmed me most about the first debate was the very real ignorance it revealed across all three debating candidates when it comes to energy. One would imagine with the environment, perhaps for the first time, being a major part of all three parties' manifestos,  that one of them might have taken a little more than five minutes to acquaint themselves with a few realities.

Both Gordon Brown and David Cameron at least acknowledged a need for nuclear power. Cameron even made the point nuclear stations take a long time to build. The point at issue is whoever has been elected needs now to act fast - In my view decisions that should have been arrived at in a considered way two decades ago now have to be taken in haste.

Clegg's opinion that the major investment should be spent on renewable is naive to the point of ridicule. His argument being nuclear power costs a lot to make. He seems to have missed the point that per kilowatt, other energy generation is also expensive, but at least nuclear power will give us potentially enough for a population set to grow to 70 million over the foreseeable future.

"Buddy, can you spare an amp?"
Will there come a time when we substitute the annual nonsense that is the Beaujolais run for another dash across the Channel to grab a case of EdF's electricity. At least our colleagues at Electricitie de France (I think using the full name emphasises where the world's largest energy firm comes from) make lots of power we can buy. This importation brings nothing to the British economy and as I've mooted before, leaves us vulnerable to the foibles of the French Government and its economy.

David Cameron did at least state that if nothing's done soon, our lights will go out. He didn't actually venture how we will find the finance, design expertise or skilled workforce to fulfil a new nuclear provision. Neither did Brown, and Clegg didn't even have it on his party's agenda.  As I write I don't know who will win. What I do know is those of us who care about energy had better be prepared to carry on the lobby!

Green posturing
I have derided businesses that display token environmentalism in the past. The Prime ministerial candidates remained guilty on all charges of green posturing. Asked by a member of the studio audience in one of the live debates, what each candidate had done personally to reduce their environmental impact, the response was so predictable. Brown said he believed in solar power, Cameron said he didn't do enough but tried not to fly too much and Clegg said he only uses his car when he has lots of kid's stuff to carry.

Did any of them simply state they turn lights off? Who ventured they might install energy efficient lighting? Who suggested they might throw less away unnecessarily? I could go on. In fact, I could go on and on and on.

If our newly elected leader, whoever they are, can't even demonstrate a rudimentary knowledge of how they might reduce their environmental impact (even if they don't actually do it) it's a worry. How can we expect incentives for the installation of active energy efficiency schemes (motion detection switches for example) or energy metering for homes, or incentives to use solar power by rebating users energy bills?

I know the Prime Minister's now in office (not necessarily - Ed), but for me the jury's still out.

Power viruses can kill productivity. But what are the six most common types we  should be aware of and how should we deal with them? Rob Morris, country manager for Powervar discusses the issues

The dangers of software viruses and their devastating impact on computer systems are well documented. These rogue programs - backdoor Trojans, Worms, etc - enter a system unseen, often incubate in silence, and eventually come to life with results that range from mildly annoying to disastrous.

Electrical disturbances are similar. In fact, they could reasonably be called ‘power viruses' since they, too, are unseen and can cause serious and expensive electronic system failure.
A typical facility experiences as many as 6,000 power viruses or more, every year. Some of these power disturbances are obvious, some less so, many are almost unnoticeable, but they all cause problems and challenges that can seriously damage productivity, from lost data and lock-ups to communications errors and hardware failures. Power viruses are contracted in much the same way as other viruses - they are passed along, often by your system's electrical neighbours. Plug your system into the wall, turn it on, and look out. You've just been exposed to an epidemic, and there are a lot of very sick electrons looking to cause problems. Some of them may take time to cause noticeable damage; others are immediately catastrophic, such as a lightning strike.

How do power viruses affect an electronic system, and what can you do to prevent power viruses in the first place?  First it is useful to understand them, so you can tackle the job of immunizing a system against their harmful effects. There are six main power viruses that can invade a system.

Voltage spikes and impulses
This virus is mostly the result of electrical equipment inside a facility. Electrical loads like elevators, motors, relays, induction furnaces and similar devices can cause sudden large increases in voltage inside the electrical system. Conditions outside a facility can be to blame as well.

Switching activities by the electricity utility and lightning strikes can cause transient impulses so intense they literally ‘blow up' sensitive micro-circuitry. This virus is deadly to electronic systems - but not always immediately. Sometimes voltage spikes and impulses are relatively small in amplitude. In these cases, the virus weakens the system components over time leading to deteriorating health and eventual failure. Other times the impulses may be so large that they cause immediate system failure.

Electrical noise
Like voltage spikes and impulses, electrical noise is generally created inside the facility by the system's electrical neighbours. Almost every electricity-consuming device contributes its share of electrical contamination. Appliances, photocopiers, printers and electronic lighting ballasts are all noise sources that can cause computers to lock up, lose data, or behave unreliably. Even computers themselves generate electrical noise. It is something of a paradox that our computers often infect other computers with power viruses.

Common mode voltage problems
Traditionally, this power virus has not received much attention. But detection of common mode voltage problems is easier and, as a result, more system problems are being traced to its existence. The condition is characterised by unwanted voltage measured between neutral and ground in the electrical system. In fact, the common mode voltage virus is probably the most serious power virus infecting electronic systems today. It occurs as a result of high impedance safety grounds, neutral conductors shared with other circuits and branch circuit lengths that are excessive.

When the electrical noise virus (already mentioned) appears between the neutral and ground conductors it becomes a common mode virus with the ability to cause lost files, system lock-ups or re-boots, communication errors and ‘no problem found' service calls.

Voltage regulation
This virus is characterised by abnormal variations in the electrical circuit's nominal operating voltage (120 volts, for example).  These variations are generally greater than +10% of nominal voltage and may last for several line cycles or more. Traditionally, this virus has been referred to as the ‘sag' or ‘surge'.

The virus is typically caused by large loads turning on and off and overloaded branch circuits or distribution transformers. In some cases, voltage regulation viruses can be the responsibility of the power utility. If an electronic system requires tightly regulated voltage (most of today's systems don't) the voltage regulation virus is likely to cause system lock-ups and unreliable operation in addition to damaged or destroyed components.

Blackouts are the most visible and easily identifiable of all the power viruses. They have the most obvious cause and effect relationship. One moment power is present - the next moment it's not - and the system is dead in its tracks as a result. The effects of unanticipated power loss are obvious. This is especially true if the system is a network or some other ‘fault intolerant' architecture. Fortunately, in spite of what most UPS manufacturers advertise, blackouts account for comparatively few occurrences of all the power viruses.

Back Door Disturbances
This virus infects your system via a secondary path. Even though they are not an AC power connection, things like serial ports, telephone lines, network cabling and I/O connections can all permit power viruses to invisibly enter a system. This virus causes driver chip failure and communication errors. The back door disturbance virus is often unrecognised. Without treatment, serious damage can occur, and lost productivity can result in substantial financial losses as well.

An ounce of prevention
There is an old adage that ‘an ounce of prevention is worth a pound of cure.  Nothing could be closer to the truth when it comes to power viruses. We are familiar with the damage that results from software viruses, and we have all experienced the debilitating and sometimes deadly results of real life viruses like flu pandemics. We go to great lengths to avoid both.
Where our electronic systems are concerned, we have learned to practice safe computing. We back up our data, avoid logging onto questionable websites, bulletin boards and networks, or clicking on emails of unknown origin. We also run anti-virus programs, install firewalls and take other preventative measures on a routine basis.

So why don't we practice safe computing where power viruses are concerned? They have the same potential devastating effects where our systems are concerned. There are five simple devices you can use to prevent the problems outlined above.  All five are required for complete immunity.

The magic pill
If there is a magic pill to prevent power viruses, it is clear prevention must be practiced as a ‘system'.  What that means is that certain prevention techniques must be used together.
Voltage spikes are addressed with a surge diverter and electrical noise with a noise filter. Each of these by themselves, however, is capable only of weakening or slowing down a virus - not eliminating it.

Isolation transformers eliminate common mode voltage problems. When surge diverters and noise filters are added to the isolation transformer, the resulting ‘system' kills all three viruses.

Uninterruptible power supplies eliminate blackouts, but in spite of many manufacturers' claims, most are not capable of preventing other viruses. Once again, the UPS must be used with the other parts of the system to achieve total virus immunity.

The backdoor disturbance can be addressed several ways. Fibre optic connections are one means of electrically closing the back door, but if ordinary copper wiring is used for communication lines, it may be necessary to employ special surge diversion techniques for these connections.

Luckily, the voltage regulation virus is no longer a serious hazard. Once upon a time, this virus was responsible for many system failures. However, today's systems use switch mode power supplies. This technology was designed as a way of reducing both power supply size and cost while simultaneously increasing electrical efficiency. To achieve these goals, switch mode supplies are designed to consume electrical power differently than their predecessors. These operational differences have created a beneficial by-product where voltage regulation is concerned. As a result, most systems enjoy substantial immunity to the voltage regulation virus. Additional preventative measures (voltage regulators, etc.) are unnecessary.

Power viruses are an appropriate description of the power quality problems that can plague electronic systems. Like other viruses, they are invisible - often announcing their presence only after some initial damage has already been done. Their effects can be a minor annoyance like a lockup or system error, or they can be catastrophic like a blown-up integrated circuit or power supply failure.

Our dependence on sophisticated technology has created an increased awareness regarding the need to safeguard system integrity. Software viruses have led to the introduction of anti-virus programs and data is routinely backed up to prevent loss. Part of this ‘safe computing' lifestyle should be the prevention of power viruses, too.

This is possible only when prevention is systematic. Voltage spikes, electrical noise, and common mode voltage is eliminated by a package that contains an isolation transformer, surge diverter, and noise filter. UPS and data line protection can be added to the system as applications demand.

From a Craftman's workshop to a modern industrial company

In our great-grandparents' time electricity was by no means a matter of course. At the beginning of the 20th century, electricity was at best available in large cities but rarely in rural areas. It was only at the beginning of the 1920's that electricity was made accessible to many small towns and villages for the first time.

The history of DEHN's success started in Nuremberg on January the 21st in 1910, when Hans Dehn founded his electrical installation company. Very soon he was involved in the complex problems of lightning protection. By 1918 he had published his first patent on this subject and started the production of lightning protection components. It is through Hans Dehn's entrepreneurship and vision that has seen DEHN become a world leader in this field.

Located in Neumarkt/Oberpfalz, DEHN is a third generation, worldwide family owned enterprise, employing more than 1000 people in Neumarkt and has seen almost 2000 young people trained over the last 100 years. The wide range of products now includes more than 4000 components and devices, specialising in three product ranges, lightning protection, surge protection and safety equipment. Recent products such as the DEHNventil, DEHNguard, Blitzductor and HVI conductor are milestones in the development of class leading lightning and surge protection and further proof of the talent within in the company.

As well as providing innovative products for lightning and surge protection, DEHN provides specifically designed protection concepts as well as engineering and test performance in the company's impulse current laboratory.

Our founder's ideas, continuous intensive research and development effort, combined with high social competence concerning its employees, has made DEHN a global market leader and pioneer in its field. Together with key principles of quality, innovation, customer satisfaction and confidence, ensures that human and engineering safety is always DEHN's uppermost priority.

To help celebrate the DEHN Groups 100 year anniversary, DEHN (UK) has expanded its nationwide seminars on BS EN 62305, the current Lightning and Surge Protection Standard. Released a new UK Lightning Protection Catalogue containing the most popular products from the UK and Europe and you will find DEHN (UK) exhibiting at Electrex in June and the M&E show in October, for more information on these and much more visit our website www.dehn.co.uk

Everyone at DEHN (UK) would like to thank you for your custom and look forward to working with you in the year ahead to make 2010 a year of real success.

It has been widely reported the new coalition government refuses to rule out a rise in university tuition fees. It has also been widely reported that the Russell Group of leading universities is calling for a fee rise, arguing that students should pay more towards the cost of their courses. Engineering degrees are expensive to deliver, and the natural worry is the subject could see dramatic fee increases, which would deter students from applying, exacerbating the country's skills shortages

The extensive use of electronics within industrial processes and buildings has meant  protection against the effects of voltage surges is no longer an option but has become a necessity. Lightning produces an extremely large quantity of pulsed electrical energy, which means surge protection devices designed to limit transient overvoltages need to be correctly specified to ensure they are effective. Tom France from Schneider Electric looks at the selection considerations, taking into account location and the types available

As business operations become increasingly sophisticated, the use of technologies such as LCD screens, computer networks, data servers and industrial equipment such as programmable logic controllers, means that protection against the effects of voltage surges is crucial.

When building a control panel, wiring is almost always the most time consuming and  costly operation. As Phil George of Eaton's Electrical Sector explains, however, modern electronic technology is making possible innovations that mean the days of conventional panel wiring are rapidly coming to an end!

Look inside a modern control panel and, depending on the application, you'll typically find a programmable controller or a smart relay and a combination of motor starters, variable speed drives, soft starters, pushbuttons, indicator lamps and maybe even an HMI display. You'll also find something else - a lot of control wiring to link all of these components together.