Features

Most modern businesses heavily rely on Telecoms, it and other electronic systems - take them away and many companies would struggle to function. The new British Standard, BS EN 62305 Protection against lightning, makes a welcome step forward by introducing procedures that will give a much greater level of protection against an electrical surge. UK contractors need greater awareness of the requirements of this new Standard, says Andy Malinski, technical director at Omega Red Group 

The damage and degradation caused by transient over-voltages to electrical systems have long been understood by electrical engineers in Europe and elsewhere. In the UK, high voltage (HV) surge arrestors are installed as standard components in the electricity supply infrastructure, fitted to avoid costly network downtime, but there still appears to be a strong reluctance to fit surge protection devices (SPD) to the low voltage (LV) networks used in commercial and domestic environments.

With only an advisory appendix for surge protection in the previous British Standard the reasons for this reluctance probably have more to do with an ingrained resistance to change rather than any hostility to the new standard. Surge protection is included for reasons of good working practice rather than some unnecessary bureaucratic standardisation with our European neighbours.

As before, the new Standard covers the need to provide structural protection but it now also addresses the need to offer protection to electrical and electronic systems against lightning currents and transient over-voltages.

Since the new Standard was introduced in September 2008 the construction industry should have noticed a change in response from contractors to their enquiries about lightning protection systems. Surge protection devices (SPDs) form an integral part of BS EN 62305 and need to be installed for a fully compliant lightning protection installation. 
Additionally there are now four different protection levels which can be applied for structural lightning protection. The level of protection is dependent on the outcome of a risk assessment which is far more complex than the outgoing standard and has many new factors to consider including building services, occupancy hours and number of people to list a few. For the UK construction industry this involves a steep learning curve. In any event, service entry SPDs will be required on all four structural protection levels for compliance.
In real terms why do we need SPDs and what should we all be doing about them? The answer is very simple. If the cables entering a structure have been exposed to lightning, either via a direct strike or by induction, then the conductive cores of the cable may carry dangerously high voltages in to the structure leading to sparking at the termination points due to the break down in the insulation of the cables or equipment.

This theory is not only being applied to the service entry points, which is a minimum requirement, but also to any exposed plant or other electrical/electronic units being fitted to the structure. Plant items on the roof (AHU etc), a control system for electric gates, car park lighting, CCTV systems may all include copper cables entering or leaving buildings.
There are three ways in which transient voltages can be introduced into a structure via copper cables:

Resistive coupling
A cloud to ground lightning strike injects a massive current into the ground raising the ground potential in the area of impact to a high level and for the current to dissipate it will seek the path of least resistance to earth. Cables running between buildings are usually connected to different earthing systems at each end and a cable connected to an earth of a lower value forms an ideal route for the induced current to follow.

Inductive coupling
A lightning discharge causes a huge current to flow; this in turn sets up a massive magnetic field.  Any conductor passing through this magnetic field will have a surge voltage induced on the cable; this is the same principle on which a transformer operates.

Capacitive coupling
Atmospheric disturbances cause high voltages to be generated.  A low voltage conductor in the area of influence of these voltages can be charged to that same voltage, this has the same effect as charging a capacitor.

Any cable entering or leaving a structure may carry back a problem but the installation of SPDs at the nearest point of entry or exit will reduce the effect of a surge. It is important to note that the service entry or equipotential Bonding SPDs are designed to handle a 10/350µs current and are commonly referred to as lightning current SPDs.

The purpose of these frontal surge protection devices is to divert partial lightning current away to earth and limit the let-through voltage to a safe level in order to prevent dangerous sparking. A competent installation company, with appropriately trained staff, should be able to advise the contractor on the best units to use - it is vital to check they comply with BS EN 62305-4 and IEC 61643.

You may be wondering why, after all these years under the previous British Standard, do we need to be looking at surge protection? The answer in very simple terms is progression; outside of the UK and especially within Europe, surge protection has been a common part of lightning protection installations for many years and the value of surge protection is well established.

BS EN 62305 has incorporated guidance and Standards employed within the UK, Germany, France and many other countries, taking available technology and applying it across the industry, just as we have with other Standards and systems in the past. The Germans have a simplified method of SPD selection which is based mainly on the use of the building to be protected and is endorsed by German insurance companies. This has evolved after many years experience and incidence recording and could well be replicated within the UK in years to come.

Under BS EN 62305 SPDs are now an integral part of lightning protection designs. It is also important to remember the certification of a system; failure to provide the entry surge protection units will mean a non-compliance with the Standard. Engineers need to understand a new system installed to BS EN 62305 should have service entry surge protection fitted as a minimum. These units should be compliant with the Standard's requirements or they may fail in the task they have been designed to carry out.

Omega Red Group has invested a great deal of time and effort in training for the design and installation of SPDs and lightning protection systems. Of course, any contractor would expect its chosen installer to know what they are talking about but a sound grasp of the requirements of the new standard is necessary to identify whether that is the case. Our engineers will always be happy to answer any questions you might have but a good starting point for understanding the basic principles of BS EN 62305, especially the SPD components, can be found in a short webcast tutorial at http://www.omegaredgroup.com/

Thorn Lighting has opened a £32m factory and Academy of Light in Spennymoor, County Durham, which the company claims to be the largest investment in lighting equipment manufacture and training in the UK since the 1940s.

Thorn has transferred production to the site, on the Green Lane Industrial Estate, from its previous base in nearby Merrington Lane, which it had occupied since 1952. The Merrington Lane site was sold to a UK-based property developer in December 2008.

The 40,000 sqm building also hosts a manufacturing facility for Zumtobel Group's Tridonic Atco luminaire components business. Overall the operation employs approximately 700 people, excluding indirect jobs at suppliers and local businesses.

Fronting the building is the Thorn Academy of Light Competence Sharing Centre, designed to provide sales staff and customers with application-specific training. The first training sessions feature Sustainability in Lighting, with half the fees raised being donated to the Lighting Education Trust.

Thorn has also expanded and upgraded its laboratory, which now features full automation of thermal test measurements, a fully anechoic EMC test chamber, expanded materials and life test facilities, and temperature control to all laboratory areas.

Helen Goodman, MP for Bishop Auckland, who officially opened the complex, said:?"This kind of investment shows, even in the current economic climate, progressive and innovative companies like Thorn still have real confidence in the the future of the local economy."
Stewart Watkins, managing director of the County Durham Development Company, endorsed Goodman's comments:?"Thorn Lighting is a beacon for manufacturing excellence in County Durham. Here we have an example of how a traditional manufacturing business has embraced the global challenges and met them head on. By investing in new production facilities, coupled with training and future development, it has ensured the long-term future of lighting production in this area."

It's easy to assume the substation on your site belongs to the power utility, but are you absolutely sure? If you get it wrong, says Damon Mount of Megger, and you're unlucky enough to suffer a transformer fault, you could find yourself landed with a bill for tens or even hundreds of thousands of pounds

In the substation, the power transformers are probably the most expensive items. And that's not the worst of it - the delivery time for a replacement transformer is typically months - or even years for the largest types. The direct and indirect costs associated with a transformer failure can, therefore, be enormous.

But there's surely no need for concern. All of the power transformers on your site are the responsibility of your energy supplier, aren't they? It may be a very good idea to check again. In a surprisingly large percentage of installations, the power transformers belong to the owner of the premises, and not to the power utility.

Of course, there's still no reason to worry, because transformer failures will certainly be covered by insurance, won't they? The answer is possibly not. Because of the huge costs involved, insurers are understandably cautious about making payouts relating to transformer faults and failures. If there is a claim, they will certainly ask for evidence to show the transformer has been regularly tested and maintained.

Since many companies are not even aware they are responsible for the power transformers on their sites, it's not too much of a surprise there are a lot of transformers that most certainly don't get the regular attention they need.

This is a special concern with the many transformers currently in use that have long exceeded their design lives. Although they may apparently still be working well, it is inevitable some of the materials used in their construction - in particular the insulating materials - will have started to deteriorate.

If an unmaintained transformer fails, whether it is old or new, it's perfectly possible that the insurers will contest the claim or refuse to pay. Let's take a look at what needs to be done to avoid this potentially devastating situation.

The first and most obvious step is for maintenance departments to check which of the transformers on their site are their responsibility. The next step is to implement a regular testing programme for these transformers.

But what form should the testing take? There are, of course, many types of conventional tests that can be applied to power transformers to check, for instance, the performance of the tap changers or the windings.

This means to build up a reasonably complete picture of the transformer's condition, a whole battery of tests is needed, which will take a considerable time to perform. During this time, the transformer will be out of service, which can be very inconvenient.

There are, however, two tests that between them can provide a wealth of information, not only about the presence of faults but also, in many cases, their type and location. These tests are sweep frequency response analysis (SFRA) and frequency domain spectroscopy (FDS).

Electrically, a transformer is made up of multiple capacitances, inductances and resistances. It is, in effect, a very complex circuit that produces a unique ‘fingerprint' when test signals are injected over a range of frequencies and the results plotted as a curve. In particular, the capacitances in the transformer are affected by the distance between conductors.
Movement of the windings, which can be caused by electrical overloads, mechanical shocks or simply by ageing will, therefore, alter the capacitances and change the shape of the frequency response curve.

The SFRA test technique for transformers is based on comparisons between measured curves, which allow variations to be detected. An SFRA test involves multiple sweeps and reveals whether the mechanical or electrical integrity of the transformer has been compromised.

SFRA tests are used to capture a ‘fingerprint' reference curve for each winding when the transformer is new or when it is known to be in good condition. These curves are subsequently used as the basis for comparisons during maintenance or when problems are suspected.

The best way to use SFRA testing is to take regular measurements on the same transformer over a period time, and to compare the results. However, it is also possible to use type-based comparisons between transformers with the same design. Finally, a construction-based comparison can be used in some circumstances, when comparing measurements between windings in the same transformer.

A single SFRA test can detect winding problems that would otherwise require multiple tests with various kinds of test equipment, as well as problems that cannot be detected at all by tests of other kinds.

As a general guide, magnetisation and other problems relating to the core alter the shape of the SFRA curve at the lowest frequencies, up to around 10 kHz. Medium frequencies, from 10 kHz to 100 kHz represent axial or radial movements in the windings, and high frequencies above 100 kHz correspond to problems involving the cables from the windings to bushings and tap changers. In modern SFRA test sets, built-in analytical tools simplify comparisons between curves.

While SFRA tests provide a lot of information about the condition of a transformer, they do not give an accurate indication of the presence of contaminants - in particular water - in the transformer insulation. Standard tests, such as the widely used Karl Fischer test, are, of course, available for accurately assessing the moisture content of transformer oil, but this is not the whole story.

In fact, it is usual for a much greater percentage of the moisture in a transformer to be held in solid insulation such as paper than is held in the oil. To further complicate matters, the moisture moves between the solid insulants and the oil in a way that is influenced by many factors including, in particular, temperature. 

Measuring the moisture content of the oil may not, therefore, provide dependable information about the moisture content of the transformer's solid insulation. This is a serious concern, as moisture in the insulation significantly accelerates the ageing process in transformers and, in addition, it can cause bubbles between windings that lead to sudden catastrophic failures.

To establish the moisture content in the transformer, the second of the tests mentioned earlier - frequency domain spectroscopy (FDS) - can be used. Initially, this may sound a lot like SFRA, as it involves measuring transformer characteristics at over a range of frequencies. This time, however, it's the dielectric properties of the insulation (capacitance, loss and power factor) that are measured over a range of frequencies, typically from one millihertz to one kilohertz.

These are, in essence, the same dielectric tests that are often carried out at power frequency, but testing at a single frequency provides far less information than is revealed by FDS testing. Unlike spot-frequency testing, FDS can, for example, reliably distinguish between a transformer that is dry but has bad oil, and one that is wet but has good oil. In the first case, the oil needs refurbishing or replacing; in the second the transformer only needs drying out.

FDS testing also has other benefits - it can be performed at any temperature, and the test can be completed quickly. Software can be used to calculate the water content in percentage terms, and modern FDS test sets typically provide accurate and detailed results in less than 20 minutes.

As we have seen, regular testing using the SFRA and FDS test techniques provides a reliable insight into the condition of power transformers, but how can this information best be used by the transformer owner?

A short-circuit fault on the transformer may cause unseen damage inside, and a damaged transformer put back into service could fail catastrophically. An SFRA test can be done before re-energising and compared to a reference trace taken while the transformer was in good working order. If the two traces match, nothing has changed and the transformer can be safely returned to service. Carrying out this test takes less than an hour, reducing outage time and saving money.

Ageing, mechanical damage and moisture content can be seen as a change in the frequency response of the transformer over time and may indicate that remedial action, such as drying out the transformer, is needed to guard against future failures. In other cases, it may show that the transformer is inevitably coming to the end of its useful life, but even then the information is invaluable.

In this situation, it may be possible, for example, to minimise the load on the transformer so it can continue in service until a replacement is obtained. And even in the worst case, there is at least a warning that failure is imminent, which can allow time for contingency plans to be made and put into place.

There is also another very valuable aspect of regular testing, which we touched on earlier. Insurance companies are more likely to honour a claim for failure of a power transformer that's been regularly tested and properly maintained so as to remedy any issues identified by the tests. Such a transformer is, of course, less likely to fail, but if it does there is at least the consolation that the insurers will foot the bill!

Even for those who are aware of their responsibilities in looking after power transformers, regular testing may appear as something of a burden. However, tests with modern instruments can be performed quickly and easily, and they yield dependable informative results. And, if the test regime eliminates just one unforeseen transformer failure that would otherwise have occurred, the effort involved in testing and the cost of the instruments used will have been repaid many times over.

When deciding whether to deploy static or rotary Uninterruptible Power Supplies (UPS), there is no easy way of weighing up comparative advantages and disadvantages. UPS systems vary greatly in physical size, weight, form factor, capacity, supported input power source, technological design, and cost.  APC by Schneider Electric makes a comparison of 3-phase static and rotary UPSs to support a data centre 

The Market
Compared to the massive global market share which static UPS systems enjoy, rotary UPS systems occupy only a small niche. According to IMS Research, only 4.3% of projected worldwide UPS revenues in 2008 will be rotary UPS systems, while the remaining 95.7% consists of static UPS.

They are also a niche within the data centre market where static UPS predominate at power levels of 500 kW and below, with the segment between 20 kW to 200 kW almost exclusively static.

Rotary and flywheel UPS systems begin to appear in use in the 200 kW to 500 kW range, for niche applications such as military and industrial. For mega data centres (< 100,000 square feet) where 500 kW to multiple megawatt UPSs are required, both architectures are present.

The Technologies
A UPS system is defined as static because, throughout its power path, it has no moving parts. The rectifier inside of the static UPS system converts the incoming utility AC current to DC, and the inverter converts DC back to clean sine-wave AC to supply the load. Regardless of the details of the internal topology, at some point there is a place where DC current interfaces with the ‘energy storage' medium - most commonly batteries, in which case it charges the batteries and receives power from the batteries when the utility power supply is distorted or fails.

In data centre applications, a 3-phase static UPS typically has a battery runtime of 5 to 30 minutes. Runtime is dictated by the size and criticality of the load together with available battery capacity. Static UPS battery systems are generally sized to allow enough time, during an outage or disturbance, to support the load while the power source shifts from utility to a standby generator. Should the generator power fail to come online, the UPS is configured with enough battery runtime and technological intelligence to allow for an orderly shutdown of the load.

The rotary UPS system is so-called because rotating components (such as a motor-generator) within the it are used to transfer power to the load. The true definition of a rotary UPS system is one whose output sine wave is the result of rotating generation.

Why the choice?
Rotary technology has been utilised for many years and came into prominence at a time when loads would commonly exhibit a low power factor and high harmonics. At first synchronous condensers which over time began to incorporate motor generators, inverters and rectifiers. Batteries or flywheels were then added for energy storage and the modern rotary UPS system was born. Ironically, the original reasons rotary UPS systems came into being, do not exist for data centre managers exist since most IT equipment is power factor corrected.

Characteristics of rotary and static UPS sytems

  • Investment

Rotary UPS systems are a fixed investment, usually oversized to accommodate future, unknown load requirements. In addition to being neither modular nor scalable (as with some modern static UPS), the upfront costs may be as much as 40% more than a comparative static system.

Auxiliary equipment costs for rotary UPS systems may also be higher since they require an external bypass switch together with special ventilation equipment to purge fumes from working areas. In the case of diesel rotary UPS, the construction of an additional building may be required to house the unit.

  • Maintenance

For a given level of availability, mechanical equipment such a rotary UPS system requires a maintenance regime incorporating weekly, monthly, annual and five-yearly checks. By comparison and depending on environment, most static UPS systems usually require only one annual maintenance visit.

While in general electronic equipment such as static UPS has a more extended useful working life than mechanical rotary UPS, they do require an investment in maintenance of, for example., batteries, in addition to occasional replacement of cards and circuit boards.

 

  • Environmental Impact
Static UPS systems tend to be installed in a building or data centre whereas rotary UPS tend to be outside in a specially built enclosure. Because they often rely on flywheels as their source of energy storage (providing only up to 10 seconds of back up), they may also be noisier as diesel generators are activated during any power ‘situation'. Batteries and flywheels both support the load until back up mains flows, however, by virtue of their greater runtime, battery supported systems may not require generator power unless the outage is extensive (most tend to be of very short duration).
  • Reliability
Both systems are quite reliable and an analysis of the MTBF of major components does not reveal any great advantage either way. However, the weak link is diesel generation which, according to the IEEE (standard 493) experience quite high failure rates (one start in 74). This may present an unacceptable risk to data centre operators.
  • Efficiency
Static UPS topologies run more efficiently than their rotary counterparts over the entire normal operating range with a very significant advantage below 50% load. Rotary UPS systems also appear to sustain higher fixed losses such as .that utilized to preheat the engine coolant and lubrication systems, to power the controls, flywheels, and pony motors associated with the rotary UPS at zero load, and the frictional and windage losses. These standby losses represent the amount of energy required to keep a motor running or to keep a flywheel spinning.
  • Architecture
Rotary UPS systems lend themselves to centralised architecture, whereas static UPS have the flexibility to also deploy as distributed UPS solutions. The advantage with rotary is that the all aspects of power backup can integrated into a single solution. While this may be attractive from a management perspective, it does present the potential of a single point of failure scenario.

Conclusion
There is a broad range of applications for static UPS systems and certainly they are the solution of choice for data centres where there is a trend towards to modular, pre-engineered solutions for all aspects of physical infrastructure including power protection, distribution and cooling - coupled with a need for high availability and high efficiency solutions. Rotary UPS systems are perhaps more suited to environments characterised by multiple short inrushes of power, for example satellite and broadcast stations. Some rotary UPS systems are used in high security installations to prevent electrical eavesdropping, as a cost effective alternative to tempest filters.

For more details, please visit www.apc.com/gb and download a copy of APC white paper #92 "A Comparison of Static and Rotary UPS".

New Labour in a nutshell

Given the government's determination to be the first to raise money by selling the right to pollute (see story below), you might think that our Lords and Masters would be determined to auction the maximum number of EU emissions trading allowances that European rules permit. Not so.

After all, there has been a considerable scandal attached to the way in which all the electricity generators have managed so far to get all their emission allowances for free. But then have promptly put up all their prices on the pretence they had bought the permits on the open trading market. Consequently they are now receiving windfall profits worth around £ 70bn. That is right. £70bn. All paid for by we consumers.

It is, therefore, entirely reasonable for the generating companies to be forced to pay out of their own pockets for the maximum number of permits permitted. Which up until 2013 is just 10% of the allowances set aside for the electricity industry.

Fair enough, you might think. The government could take the money in from at least that 10%. And maybe follow the example of the Dutch or the Austrians, and ring-fence the money to help poorer people cope with these inflated power bills?

So is that what is planned? Not on your life. The UK government has decided it won't take up the right to sell all 10% of the allowances to the generators. Instead, it has decided to take pity on these poor penurious multinationals. And just auction 7%. Rather than the permitted 10%.

Why have the Whitehall mandarins decided to hand out the extra 3% free and gratis, and so forgo around £600m. Money that could have gone to help eliminate fuel poverty. Apparently, the official explanation is that they were worried that if they did auction more than just 7%, they might overshoot that 10% maximum. Such caution might have justified limiting the amount to be auctioned to (say) 9.75. But only 7%? Phooey.

Oh ,and apparently it is "not government policy" ever to ring fence revenues for any specific piece of expenditure. Instead at the start of this financial year, the government celebrated by cutting the main fuel poverty programme, Warm Front, by 20%. It is New Labour's philosophy in a nutshell: Take away from the poor. Give to the rich.

Pipped to the post

Such is the decline in the value of the pound that, in its rush to be the first European government to auction  allowances under the EU carbon emissions trading scheme, ministers have ‘lost' the taxpayer around £10m.

This is because the entire trading system - which covers all types of electricity generation -   only recognises the euro as a currency. In consequence, all such auctions have to be in euros. But whereas,  when the sale took place in mid-November, the pound was worth 84 eurocents, right now it is around parity - in other words, worth one whole euro.

With the right to emit each tonne of carbon dioxide selling at 16.15 euros, this converted to an income for the government of some £54m in November. However, had the government waited until the New Year, the exchange rate would have upped the value to around £64m. I really don't think the loss of revenue was worth the dubious honour of pipping all those other European governments to the post to start auctioning.

Can't beat them? Join them

Back in 2006, the government set up a competition. It offered to pay the majority of the costs to build the first 400 megawatt Carbon Capture & Storage (CCS) demonstration plant.
Most of the Big Six electricity generators decided to compete. Last July the government announced which  schemes were on the short list. The German power company RWE, which trades here as npower, was mightily miffed when its entry was eliminated.

It huffed and puffed. It announced it was considering legal proceeding against the government. For six months m'learned friends were rubbing their collective hands with glee, at the prospect of a lengthy full-scale battle in the Courts.

But then suddenly the threat of Court proceedings disappeared. Why? Because RWE has gone and bought 75% of a company called Peel Energy Carbon Capture. Which, unlike RWE, happens to have made not just the government short-list. It also just happens to be the bookies' favourite to be the winning CCS proposal. As they say, if you can't beat them, then you just have to join them.

Cost of imcompetence

The late Professor Roland Levinsky was a pioneering immunologist, and vice-chancellor of the University of Plymouth. He died because, in atrocious weather conditions, he walked into a live 11,000 volt power cable left dangling across a footpath near Wembury, Devon.
It was not as if the cable owners, Western Power Distribution (WPD), did not know about their insecure high-voltage cable. The company had been contacted several times by concerned people who had seen the cable hanging loose.

But instead of logging the problem as "dangerous", the company call centre instead listed it as just "miscellaneous". So the power was never turned off. And an engineer despatched to fix the fault was diverted elsewhere.

And the cost to WPD for its incompetence, which took the life of a distinguished academic? The paltry total of £270,000. Including legal costs. In a world where electricity companies are walking off with billions worth of unearned, windfall profits, such judicial generosity makes me despair.

Electrical distribution and motor control has a major role to play in today's industry. The systems that control it are usually referred to as motor control centres (MCCs), distribution or switchboards. Darryl Wells-Pope from Rittal explains

The construction of the enclosure is divided into a number of many different sizes of compartments arranged in rows and columns with each compartment door opening separately. These compartments contain electrical devices, which are then connected to copper busbars that power motors or distribute electricity as a distribution or switchboard.
Every compartment within the MCC, distribution or switchboard will normally house a circuit breaker and/or a motor starter normally side by side with sufficient space left over for control, power transformer and a relay. As modifications are inevitable, the compartments need to modular and available in various sizes that can accommodate different sized parts.
When compartments contain circuit breakers, the compartment door should have a handle through it to act as a means of disconnecting the power from the equipment; without opening the door. This will also allow each compartment to be shut down separately without interfering with the other processes. 

With modular MCCs, distribution or switchboards it is essential a level of separation is achieved and these forms of separation extend from ‘Form 1', which is based on a traditional open ‘cabinet' type MCC construction to the extremity of ‘Form 4b Type 7' where all starters or feeders are separated from each other - even the control terminals. In such solutions it is advisable that incoming cables can be brought into large cable chambers, with aperture sizes of up to 400mm wide, providing greater manoeuvrability for the onsite contractors and, therefore, quicker and easier installation.

Type testing in low voltage switchgear is increasingly becoming an issue of prime importance worldwide. Type tested panels in accordance with IEC 60439 Part 1 assure a high level of personal protection as well as system protection. However, one important thing to remember is to ensure all plastic materials used for the busbar supports are self-extinguishing in accordance with UL 94-VO. With such type tests, more safety is assured through heat dissipation and comprehensive short circuit resistance testing. When type tested along with various manufacturers' protective devices, MCCs offer even more flexibility of system permutations.

With MCCs or distribution boards, it is paramount that systems are totally flexible in their makeup and that busbar mounting can take place either in the roof area, the rear or mounted into the base/floor area. Such options allow for all eventualities, and offer a wider scope to cater for any electrical application, which may be required.

The design of any MCC, distribution or switchboard can be time consuming, not only does the front ‘general arrangement' require organising to make use of the valuable space, but the internal components require careful planning in order to make sure fine details such as mounting plates and busbars are included. By utilising a specialised engineering software package, designers specifying and designing MCCs can now produce drawings and parts lists within minutes. If the right software is chosen it should also allow modifications and additions, which may be required at a later date, to be easily incorporated, be able to specify the individual component parts, which allows for a quick and effortless placement of the MCC order, and allow completed drawings and parts lists to be exported into various software packages.

As so many projects are now expected to take place with a fast turnaround, when considering the self-build option it is essential the instructions are clear so the mechanical assembly can take place quickly and easily. What happens if any of the side panels are damaged during transit? Are they easy to replace? Can they be replaced?  These are questions that could cause a problem if the system is not of a modular design. With modular MCCs these issues don't tend to exist as all external panels can quickly and easily replaced, with the added bonus that any earthing cables conventionally required to be replaced can be eradicated due to ‘self-earthing' panels.

With any purchase of a motor control or distribution board it is important to consider the future use of the equipment. Although it may be suitable for today's business requirements, will it be able to cope with tomorrow's demands?  Whether the MCC can be easily extended is therefore something that needs to be considered. If it is to be extended it would be advisable to choose an MCC where the individual enclosure units can be easily bayed in the future. Consideration also needs to be given to the busbar extensions; can they be achieved easily with standard products? Are the products available quickly so the build is not delayed? And what about the compartment sizes? Can these be accommodated easily into an existing structure? Are special parts required? Do doors have to be especially manufactured or are they available off the shelf?  All of the above elements are paramount when selecting an MCC.

Any motor control centre, distribution board or electrical switchboard needn't be a complex structure if all the elements are considered, are easily and readily available and can be expanded as and when required.

Now in its third successful year, the latest in a series of regional exhibitions and conferences, sponsored by DuPont, will take place at Sandown Park, Esher, Surrey on the 24 and 25 February 2009. The event combines a seminar programme, organised by the British Safety Council, with an exhibition supported by the industry's major manufacturers and service providers

One of the most popular elements of Health and Safety 09 - South is its free seminar programme  which for the first time will this year be organised by the new official educational partner, the British Safety Council. Elements which the organisation has said it will concentrate on in regards to the seminar programme include focusing upon ‘health' as well as safety. As Nina Wrightson, Chairman of the BSC says "With the epidemiology of health being a less straight forward issue than safety, as exposure is not as easy to predict as it takes place over the long-term, it is often ignored and we intend to tackle this problem."
The educational programme takes place on both days of the event and seminar highlights on the first day, 24 February 2009, include Corporate Manslaughter/Homicide - The Impact, by Kevin Bridges of the law firm Pinsent Masons LLP. This seminar will introduce the Act and the new statutory offence of corporate manslaughter/homicide for those that are unfamiliar with its content and its anticipated impact on corporate and personal liability. Bridges will also look at how the Sentencing Advisory Panel has suggested that those convicted under the act (which came into force on 6 April 2008) should face a substantive fine - between 2.5 and 10% of their annual turnover.

Also taking place on the first day is Asbestos - The Hidden Killer presented by Stephanie Beach of the Health and Safety Executive. Beach's presentation will provide an update on current asbestos issues and recent initiatives including a summary of the HSE's recent, national, media campaign designed to raise awareness amongst tradesmen of the risk of exposure to the substantial amounts of asbestos still contained in many buildings. 
Seminars on the second day of the event, 25 February 2009, include Working at Height by David Thomas of William Hare, the structural engineering company. David will cover all aspects of safety when working at heights, setting out the simple hierarchy for managing and selecting equipment for work at height and outlining some of the fundamental measures required for a safe system of work as required by The Work at Height Regulations 2005 that apply to all work at height where there is a risk of a fall liable to cause personal injury.
As well as the busy educational schedule, more than 100 exhibitors are represented in the continually expanding exhibition area. Personal Protective Equipment (PPE) is an area which is well supported with the show's main sponsor being DuPont, with Ansell Healthcare Europe and Aearo Technologies as event partners. Other PPE suppliers such as BM Polyco and Marigold Industrial also have stands and the breadth of PPE covered includes everything from specialist protective clothing and gloves, to eye wear, ear plugs, high-visibility garments and more.

For those interested in working at height solutions, helping maintain safety and compliance in this area requires specialist equipment and advice which at Health and Safety 09 - South is available from the likes of A-Plant, Scafftag and Pammenter & Petrie.

Another element of the event which is provided free by event partner Principal People is the fire safety demonstration. Here, fire safety professionals give regular demonstrations throughout the two days about how visitors should deal with certain types of fire from the classic chip pan blaze to more complex fires. The team will be demonstrating the use of extinguishers and inviting visitors to bring a blaze under control with hand held extinguishers.

Health and Safety 09 - South also provides visitors with a the opportunity to talk to key industry bodies, professional and trade associations such as the Health & Safety Executive, the Asbestos Control and Abatement Division (ACAD) and the Chartered Institute of Environmental Health (CIEH) and IOSH all of who are exhibiting. For a full list of exhibitors visit: www.healthandsafetyevents.co.uk

Registering for the event or a seminar is free. However, visitors are advised to do so in advance to guarantee a place. Registration is via: www.healthandsafetyevents.co.uk or for those without internet access registration can be completed by calling the exhibition helpline on 0870 4866816. 

Two new white papers from Rockwell Automation reveal how progressive manufacturers are focusing on safety automation solutions to keep their people safe, their machines working and their bottom lines robust. The papers credit this focus to the adoption of a ‘holistic approach to safety' and ‘Providing the value of safety', which emphasise global standards, innovative technologies, trained personnel and ongoing risk assessment, all working together

"A Holistic Approach to Safety Automation" highlights the differences between the manufacturing industry's historical approach of separating safety solutions from the automation system, and today's integrated functional approach to safety. It also outlines the inherent benefits this direction offers, namely minimised risk and increased productivity.

"By integrating safety functions into their overall automation strategy platform, manufacturers can create a safer working environment for employees and reduce the risk of an incident that could have a negative environmental impact. It also improves manufacturing processes that optimise productivity and key performance indicators, such as overall equipment effectiveness, ultimately leading to increased profits," said Craig Resnick, research director, ARC Advisory Group. "When manufacturers adopt this holistic approach to safety, they are leveraging state-of-the-art technology to help protect their people, as well as improving their company's global competitiveness."
A fundamental shift in two essential and related areas has helped make this new functional approach to safety possible. The first is major developments in safeguarding and control technologies - most notably the advent of new microprocessor-based technologies in lieu of electromechanical or hard-wired control. The second is the evolution of global safety standards to allow these new electronic technologies to be incorporated into industrial safety systems.
The increased popularity of proactive risk analysis is also helping to propel the growth of this holistic approach, according to the paper. The objective of the safety system is to help protect people by making processes and machines safer without decreasing productivity. Manufacturers that conduct risk assessments are several steps closer to achieving all of the above - and in so doing, they help reduce risk and the costs associated with it.
"The holistic approach to safety is a best practice that ARC hopes even more manufacturers adopt," Resnick said. "Manufacturers should challenge their automation suppliers to provide innovative safety solutions and services to support their quests to operate safer, while simultaneously increasing productivity and profitability. Rockwell Automation appears to have met this challenge with their integrated safety solution offerings."
‘Providing the value of safety' outlines the long-term financial benefits manufacturers can reap by integrating comprehensive machine safety programmes into their workplaces as a form of insurance against potential risks.
 Functional safety protects workers by reducing incidents but also reduces the associated costs. These include insurance premiums, claims administration fees, workers' compensation claims, risk management department costs (salary, travel, fringe benefits, and so on), legal fees, and other related costs such as government fees, assessments and consultants.
It benefits users by cutting costs without reducing safety. It provides a high safety/failure ratio so that users can maximise both production and safety. 

Functional safety is the part of the overall safety implementation that depends on the correct functioning of the process or equipment in response to operational safety inputs. It relates to the physical operation of a machine or process. In other words, functional safety equals the confidence in the ability of the safety-related control system to perform its function over a specified time period.

The name ‘functional safety' is often associated only with programmable safety systems, but this is a misconception. It covers a range of devices, such as interlocks, light curtains, safety relays, safety PLCs, safety contactors and safety drives that are interconnected to form a safety system.

Using functional safety and its applicable standards requires the availability of data such as the probability of dangerous failure per hour (PFHd) or mean time to dangerous failure (MTTFd). In this way, the user can calculate the reliability of the safety system. This should not be regarded as an absolute and certain value but more as an indicative and relative quantification that can prevent the use of unsuitable equipment.

Functional safety falls under the umbrella of the risk reduction process which involves the following steps: 
- Eliminate problems by design using inherently safe design concepts. 
- Safeguarding and protective measures with hard guarding and safety devices. 
- Complimentary safety measures including personal protective equipment (PPE). 
- Safe working practice achieved with procedures, training and supervision.
Functional safety addresses the safeguarding portion of the risk reduction process. When users implement integrated safety by designing systems so that safety and environmental considerations are fundamental elements, they include functional safety measures as part of the safety system.

When designing equipment and associated control systems, a hazard analysis will help determine whether functional safety is necessary to ensure adequate protection against each significant hazard. If so, then users can integrate functional safety into the machine design requirements, implementation and validation.

A hazard analysis identifies what has to be done to avoid hazardous events associated with the operation and maintenance of the machinery. In addition, a risk assessment gives the safety integrity required of the safety system for the risk to be acceptable. 
As safety becomes more and more important in today's world, it makes sense for systems to be fully integrated into the factory environment.  The fact that it provides other significant benefits along the way is a real bonus.

The white papers "A Holistic Approach to Safety" and "Providing the Value of Safety" are both available at: http://www.rockwellautomation.com/solutions/safety/

 

John Clarke, of Zucchini EdM Transformers, discusses the environmental and cost-saving effects of cast-resin transformers

A transformer is a device that transfers electrical energy from one circuit to another through a shared magnetic field. A key application is to ‘tap off' 11,000 volts (11 kv) of electrical power from the national grid and step it down to 415 volts, which is the normal 3-phase electrical power system used in the UK for commercial, institutional or industrial applications. A transformer therefore makes raw electricity ‘usable', as well as allowing it to travel through cables. In fact, most of the world's electrical power has passed through transformers by the time it reaches the consumer.

Large, high-power transformers, in particular, need to have a built-in cooling facility to transport heat from the interior. Thus, one of the numerous ways of classifying transformers is according to cooling type. For example, for power transformers rated up to a nominal kVA, natural convective air-cooling, often fan-assisted, is adequate. Traditionally, oil transformers relied on highly refined mineral oil as a cooling medium, while the latest generation cast-resin transformers, the transformer core is insulated by a thin coating of inorganic material.

FIRE SAFETY
Over the last decade, remarkable advances in materials technology and manufacturing methods have fostered the popularity of cast resin transformers, particularly in fire-sensitive locations such as high-rise structures, hospitals, and public buildings where the transformer is located indoors and a fire outbreak would be particularly hazardous because of the high density of people.

Safety is high on the list of benefits provided by cast resin transformers. The advanced epoxy mixture used in EdM transformers is a non-hazardous material, which is both fire-resistant and self-extinguishing. Even when the material is exposed to arcing, no toxic gases are produced, and the transformer can be safely situated close to the load, saving on cabling, civil works and transmission loss.

Another key benefit is the fact that cast resin transformers require no maintenance during their lifetime.

NON-POLLUTING
Compare all these benefits with the disadvantages of traditional oil transformers with their relatively low fire point, pollution potential, higher installation costs (due in part to the fire-protection and containment measures often needing to be installed along with the installation), and a high maintenance requirement.

Oil-cooled transformers are not, it has to be said, a favourite with insurance companies. Oil, of course, is a non-renewable resource, while EdM transformers are insulated in a sustainable material, which has been developed and refined over 15-years to comply fully with European Union and national directives on the protection of the environment. Indeed, they do not pollute the environment where they are installed and are therefore recommended for all ISO locations, a standard that helps organizations minimise the negative effects of their operations on the environment.

AGGRESSIVE CONDITIONS
As well as protecting the environment, the high quality epoxy resin filled with silica and trihydrate alumina, that have developed to encapsulate transformers, stops moisture  ingress, thus preventing electrical breakdown under load, as well as inward pollution from the environment. This not only makes the transformers ideal for damp or dirty conditions, but extends the life of the transformer's working parts and eliminates maintenance. EdM transformers are also coated in high-vacuum chambers to reduce air and other gases in the resin that could produce partial earth discharges. In effect, they thermetically seal the transformer's core. As a result, consultants and specifiers looking for standard transformers with power outputs in the range of 100 to 3,500 kVA (and up to 16,000 kVA for specific projects), get complete peace of mind.

Another point is cast resin transformers do not have the noise and vibration problems associated with oil-based machines.

Cast resin transformers are now available in different specifications to meet the needs of the climate or hazardous and unforgiving environments, exceptionally cold ambient temperatures and environments with high fire risk.

MORE ENVIRONMENTALLY FRIENDLY
One of the most gratifying outcomes of installing environmentally friendly technology in recent years has been the realisation by individuals and companies that saving the environment  - can also save money! As well as being favourably priced, cast resin transformers are exceptionally energy-efficient, producing a high transformation yield and thus consuming less input energy.

At Zucchini EdM, we have developed ‘mathematical models' highlighting the savings that can be made by the user of a given electrical item on a case-by-case basis. For example, a 1,000 kVA energy-efficient transformer can produce savings of  €30,000 over a 20-year period, the equivalent of 20 MWh per year. The European Commission has assessed if equipment such as this were brought into general use, emissions of 11 million tonnes of carbon dioxide - equivalent to the electrical power used by 5 million homes - would be avoided.

The growing demand for clean, reliable power contrasts sharply with pressing concerns over energy supply, quality and price, and environmental issues. Peter Bentley, sales director of Uninterruptible Power Supplies (UPSL), makes the case for a new generation of modular UPS systems which are helping to address these issues

With dwindling North Sea oil and gas reserves and nuclear and coal-fired power stations nearing the end of their service lifetime, there is considerable uncertainty about the UK's future energy supplies. Combined with current price rises and pressure to meet environmental objectives, energy efficiency is undoubtedly of increasing importance to businesses. The consequent drive for new technologies that reduce power consumption and carbon emissions has been key to the development and uptake of modern, modular uninterruptible power supply (UPS) solutions that offer significant improvements in efficiency - not just in terms of energy but also physical footprint.

The proliferation of microprocessor-based equipment in industrial and commercial sectors has dramatically increased the numbers and types of electrical load falling into the ‘critical' category. The importance of protecting such sensitive and commercially vital IT and electronic systems against mains failures is now well understood, and as a consequence, continued growth in the UPS market has meant electrical contractors are now increasingly responsible for specifying and installing systems.

Reducing footprints
Energy and environment considerations are coupled with the high costs of real estate, particularly in city centre locations, and this has emerged as a major incentive for businesses to seek space savings for their IT systems and ancillary equipment.

IT energy consumption has increased by 400% per server rack since 2003, having grown almost exponentially. Demand for power can lead to the plant actually being larger than the data centre it is supporting, so it goes without saying that any contribution to space saving is to be welcomed.

For example, a floor space reduction of 70% could be achieved by replacing a 10 year old 400kVA parallel redundant UPS system (running at 45% of its rated capacity) with a new decentralised parallel architecture (DPA) 200kVA parallel redundant UPS system.
Such savings make an important financial contribution given the high cost of commercial property. For example, the biannual property market report (January 2008) from The Valuation Office Agency, shows that city centre office block rental values can reach over £300/m2 per annum.

The design and layout of commercial property frequently imposes physical constraints on the installation of IT systems and supporting infrastructure, particularly in old or converted buildings. Financial institutions for example have historically often occupied city-centre sites with considerable space challenges. On many occasions, installing modular rack-mounted transformerless UPS systems has proven to be the only viable solution for such exacting performance and floor space specifications, since they provide high power density and the smallest physical footprint on the market. Compared with legacy systems, such modular UPS systems typically take up only a quarter of the floor space.

Trying to cater for future needs with traditional stand-alone UPS systems can also lead to over-specification, creating a wasteful gap between installed capacity and the size of the actual critical load, and making inefficient use of costly floor space. However, today's modular, rack-mounted systems can be right-sized by inserting or removing ‘hot-swappable' modules, enabling power to be added as requirements grow without any footprint penalty.
This scalability helps specifiers and installation contractors to make flexible plans for space requirements and to manage this valuable resource in terms of immediate and future needs. Modular, transformerless UPS systems, with decentralised parallel architecture, provide a flexible, space-efficient and moveable system, versus monolithic stand-alone installations that may never be used to capacity and would certainly be a challenge to relocate.

Decentralised parallel architecture
Today's modular UPS systems are uniquely designed to remove any single point of failure, achieving virtually zero downtime and the elimination of costly disruptions to mission critical operations.

Decentralised parallel architecture works by paralleling independent rack-format UPS modules. This means that each individual module contains all the necessary hardware and software required for full system operation. With all critical components duplicated and distributed between the independent modules, potential single points of failure are eradicated, giving guaranteed system uptime.

With a minimum of one module over and above that required by the ‘capacity' system, the load is supported with UPS power if any one module shuts down, thereby providing full N+1 redundancy and significantly increasing system availability - an important factor at a time when power supply in the UK is becoming less dependable but more critical to business operations.

According to a recent report by business research and consulting firm Frost & Sullivan, rising energy costs, declining power quality and concerns over carbon emissions have highlighted the vital role of energy-efficient UPS. Commenting on the report, Frost & Sullivan programme manager Malavika Tohani commented: "Spiralling energy costs and increasing attention to reducing carbon emissions are driving the growth of energy-efficient UPS systems. It is therefore vital that applications consuming high amounts of power such as data centres and industrial applications adopt energy-efficient UPS."

Cost savings
Concerns over relatively high initial prices have in the past inhibited the uptake of energy-efficient modular UPS systems. However, as energy costs continue rising, total cost of ownership (TCO) increasingly favours a high efficiency solution as savings quickly compensate for the initial purchase premium.

By comparing the TCO for a traditional UPS and for an advanced modular system the savings become very apparent. The TCO advantage of modular UPSs derives from factors including size, transport and installation logistics, power security, maintenance, training, spare parts and upgrading, as well as energy costs and carbon emissions.

Modularity improves efficiency by working closer to the load capacity than traditional UPS systems but without sacrificing the security of the system. The more a load approaches the capacity of any UPS, the more efficiently the UPS operates. A traditional standalone parallel redundant system is typically just 50% loaded while a modular solution typically achieves a 70% or higher loading. This reduces both energy and UPS cooling costs.

As the table shows, for a modular 200kVA N+1 UPS system supplying a load of 180kVA, the TCO savings over five years can be nearly £145,900, with nearly 712 tonnes carbon emissions reduction and a carbon neutral offset equivalent to 1083 trees.

The financial benefits, efficiency and flexibility offered by modular UPSs means they are increasingly the de facto choice for ‘future-proof' power protection and to meet today's power supply and environmental challenges.

The introduction of two key European Directives in 2005/2006 changed the face of emergency lighting--and most particularly emergency lighting testing--forever. These two Directives--EN50172 Emergency escape lighting systems and EN62034 Automatic testing for battery powered emergency escape lighting--opened the door to new opportunities in the emergency lighting domain, and brought with them implicit challenges. Paul Wilmshurst explains

To-date, many of the challenges faced when implementing emergency lighting schemes have derived from a disjoint in conventional design approach. Emergency lighting schemes have traditionally been addressed by disparate systems--systems that are typically split along the boundaries of architectural and commercial energy management lighting.

The 2005/2006 European directives, coupled with significant advances in lighting control and monitoring technology, are creating a trend towards a more holistic approach to emergency lighting system design. This approach ‘engineers in' the emergency lighting functionality--most notably the mandatory testing regime--across the building or campus as a whole, rather than patching together disparate systems, or tacking on testing functionality as an afterthought.

Such holistic emergency lighting system design is empowered by four key technologies: advanced luminaire communications, centralised system monitoring tools, total campus distributed control architectures, and the increased use of campus-wide Ethernet backbones.
Innovative luminaire, ballast and inverter control and monitoring protocols - such as DALI and DALI's extended command-set, (which is currently under industry discussion) - provide the system ‘eyes and ears'. Complementing this, user-friendly PC-based graphical control and monitoring interfaces provide a centralised ‘total view' of the entire lighting installation, both operational and emergency. Powerful lighting system distributed control architectures empower the holistic design, by providing ubiquitous connectivity across the entire building or campus. Increasingly, such distributed control architectures are complemented by a building- or campus-wide Ethernet backbone, allowing system-to-system bridging, plus connectivity to services outside the building, such as Internet monitoring and e-mailing of event alarm notifications.

These four core technologies, coupled with advanced lighting system design, are underpinning an essential holistic view of the building emergency lighting network. Together, they are empowering a new generation of emergency lighting testing - one that is seeing automated and semi-automated testing actually engineered into the system itself.

Jim Wallace of Seaward Electronic urges employers to take a common sense approach to ensuring the safety of electrical equipment, as any cutbacks on safety procedures carry considerable risks

With HSE reporting around 1,000 workplace electrical accidents and 25 deaths each year, reducing the dangers associated with the use of unsafe electrical appliances in the workplace is of vital importance. Fires started by poor electrical installations and faulty appliances also cause many more deaths and injuries - and considerable disruption to business activities.

Nevertheless, in pursuit of maintaining cost efficiencies during difficult economic times, health and safety procedures are often among the first activities to be reviewed for cost cutting purposes.

However, before taking any action in this respect, company owners should fully understand their obligations and the risks associated with any short circuiting of proper health and safety procedures.

Employers have a duty of care obligation under the Health and Safety At Work Act 1974 to ensure the electrical safety of all those using their premises.
As well as facing penalties from the HSE, those that ignore their responsibilities not only put their employees and customers at risk, but may also invalidate their commercial insurance policies and liability protection.

In addition, the introduction earlier this year of the Corporate Manslaughter and Homicide Act also makes it easier to convict organisations guilty of negligence - with fines of more than 10% of turnover with no upper limit one of the penalties in waiting.
For any organisations contemplating a less rigorous approach to health safety in the interests of cutting costs, the stakes have never been higher.

The legal requirements relating to the use and maintenance of electrical equipment in the workplace are contained in the Electricity at Work Regulations 1989 (EAWR).  Regulation 4(2) of the EAWR requires that all electrical systems are maintained so as to prevent danger.
This requirement covers all items of electrical equipment including fixed, portable and transportable equipment. Crucially Regulation 29 adds that a suitable defence is proof that all reasonable steps and due diligence were exercised in avoiding unsafe regulations.
In response to this situation, the IEE's Code of Practice for In-Service Inspection and Testing recommends that maintenance of electrical equipment is carried out in four stages - visual inspection, a test to verify earth continuity, a test to verify insulation and a functional test.
Electrical portable appliances are often roughly handled when moved from place to place, operate in a variety of environments and in many instances have more arduous and onerous usage compared to fixed equipment. As a result, at any time around 20% of electrical appliances used in workplaces could require re-testing to ensure that they do not pose a hazard to users.

Workplace safety programmes must therefore be capable of detecting potential problems with electrical appliances before they occur. For example, how can gradual deterioration in the electrical integrity of power tool, kitchen appliance or piece of IT equipment be diagnosed?

he emphasis on maintaining a safe working environment is therefore constant and some examples of the sort of horror stories uncovered by periodic inspection and test programmes illustrate this point perfectly.

For example, one public sector employer now insists all faulty equipment must have the whole lead cut off as close to the appliance as possible.  This is the result of an earlier situation when a caretaker rewired a plug onto an appliance that had previously had the plug removed after failing its regular test.  The failed but reconnected appliance was then responsible for causing a fire causing thousands of pounds worth of damage.

In an engineering company, factory workers risked their lives by continually replacing a fuse that persistently failed in a power tool with a solid metal bar, rather than raise the issue and question why the fuse was always blowing. The temporary modification was uncovered during a periodic portable appliance test.

Warehouse equipment when left around floor areas can be particularly liable to cable damage from fork lift trucks.  In one case a warehouse operative preferred to continue to use an electric drill with exposed wires rather than admit that it had been left out and damaged.

Even in offices, employees have been found to be taping up cracked power packs with cellotape rather than having them replaced. Elsewhere, in a school laboratory, a safety engineer had to take all the soldering out of service after the students had used them to burn through their own plugs.

All of these highly dangerous situations would not have been detected without the presence of regular inspection and testing procedures. Although many obvious defects can be identified by visual checks, inspection needs to be linked with a programme of testing to reveal potentially invisible electrical faults such as earth continuity, insulation integrity, correct polarity, unacceptable earth leakage and other potential problems.

Of course the need for establishing effective safety measures has to be balanced against practical aspects; realistic precautions for one organisation might be unacceptable for a larger or different type of business. In this respect guidelines on periodic safety testing intervals are provided in the IEE Code of Practice and supported by various HSE guidelines.
Given this situation, companies engaged in cost efficiency introductions need to think very clearly about the potential consequences.

In considering any cost reductions a clear distinction needs to be made between, for example, what might be regarded as potentially unnecessary and costly advice against those potentially vital life (or business) saving procedures.

This particularly applies to in-service electrical safety testing and ever more at a time when companies may be tempted to delay the replacement of older or damaged equipment with new tools and appliances, which so often happens during difficult economic conditions.
Where electrical safety is concerned, there is absolutely no room whatsoever for taking risks or adopting dangerous cost cutting practices.