Features

In any workspace, be it an office or an assembly/production area, lighting needs to be both flexible and efficient if it is to meet all of the criteria of end users. Rodger Henderson of Waldmann Lighting explains why freestanding direct/indirect lighting can provide the ideal solution in many situations

Flexibility in the workplace has now become integral to the majority of businesses and it's important the building services offer a comparable level of flexibility. In this way, the services are able to adapt to change and continue to deliver the required performance - ideally with a high level of energy efficiency.

This flexibility arises through several drivers. On a production line, for example, there may be a change of workflow to suit a new product line or to introduce greater efficiency. In offices, the increasing popularity of flexible working practices such as hot desking and home working have contributed to a more fluid environment where change is the norm.

With inflexible services, as are all too frequently found in many workplaces, the cost and disruption of reconfiguring services often proves prohibitive. The result is that no changes are made and the comfort and efficiency of the workplace are compromised.

For example, when a workplace is first laid out the lighting is often designed to suit that layout, which makes perfect sense. However, when that lighting is a fixed ceiling installation, any reconfiguration can be very disruptive as luminaires may need to be moved to different positions in the ceiling grid. This also leads to re-wiring work and very often the spatial relationship between luminaires and sensors changes so these need to be repositioned and/or reprogrammed. Much of this work will involve access to the ceiling void, so the space either has to be vacated or the works are carried out in evening at weekends. In a production facility, neither option will help to maintain productivity.

Even when the workspace doesn't change, an element of flexibility is required to address the different visual requirements of individuals - either because of natural variation in visual acuity or because they are performing tasks with different visual requirements.

For instance, in a conventional design with ceiling mounted lighting the luminaires are often controlled in groups, so that people are often forced to come to an agreement with their colleagues about light levels, rather than having control of their own lit environment. With the UK's ageing workforce, this is a growing problem as older people will have different lighting requirements from their younger colleagues.

Similarly, even if all of the staff had identical visual characteristics, their visual requirements would vary through the day as they switch between paper and screen based tasks or addressing tasks of varying complexity. For example, assembling enclosures in one section of a production line may be less visually demanding than wiring and soldering components into a printed circuit board.

Of course, some more sophisticated systems do offer a level of personal control within zones but users may be required to master a complex lighting management system, and this is still not as effective as providing control at an individual workstation level.

Failing to address the visual needs of the workforce can also have a negative impact on staff morale and, consequently, productivity. In fact, research carried out at the Rensselaer Polytechnic Institute, a leading establishment in workplace research, has shown that creating a user-friendly lighting configuration can achieve an increase in productivity of as much as 3%.

Addressing this situation requires a combination of flexible lighting at a local level and controls that are easy and intuitive to adjust. In spaces with normal ceiling heights, such as offices and many production/assembly areas, freestanding direct/indirect luminaires can address all of these requirements. And these are particularly effective in ‘cleaner' production/assembly areas with reflective walls and ceiling.

Indeed, in the rest of Europe the benefits of this approach have been recognised for many years but the concept has been slower to take off in the UK. However, thanks to the combination of flexibility and energy efficiency provided by freestanding lighting, interest is growing rapidly.

Such direct/indirect light fittings are positioned at floor level and can be provided as freestanding fittings adjacent to the furniture, or fittings attached to the furniture.

This approach uses the ceiling as an extensive reflector to create a bright and spacious feel in the space, and can therefore be an effective alternative to fixed ceiling lighting. It also corresponds to the greater emphasis placed on uplighting in best practice lighting designs, as determined by the Chartered Institution of Building Services Engineers (CIBSE) in its Lighting Guide 7.

At the same time, the directional component can be controlled to adjust the level and direction of light incident on the work surface. In this way, the users can adjust the lighting to suit their tasks and personal preferences. Because of the location of the fitting, all of the operating controls and power displays are at working height for easy access and visibility.

Alternatively, freestanding lighting can be used in conjunction with separate task lighting, so the benefits of the uplighting are retained while the user has control of their individual lighting from the task lighting. In this case, complementary styles of the different fittings help to retain a consistent ‘family' feel to the lighting throughout the space.

Inevitably, freestanding lighting takes up some floor space and changes the view across an office space so it's also important to choose a compact design with a small footprint. It should also be aesthetically pleasing in its own right and in a style that that will blend with other furniture in the space. So freestanding lighting can not only improve the flexibility of the lighting installation, it can also enhance the aesthetics of the space through both its light distribution and its visual appearance.

In terms of the need for a flexible solution, as described above, clearly freestanding lighting is much easier to move around with the furniture - simply by picking it up and moving it. Similarly, furniture mounted lighting can be removed quickly and easily with just an Allen key and a screwdriver.

From the end user's point of view, it also enables the relocation of the lighting to be included as part of the general move of other ‘office furniture'. With fixed ceiling installations this would need to be set up in the facilities management systems as a separate job, so freestanding lighting also helps to reduce the administrative burden of moving people around.

Also, it is very easy to add freestanding lighting to an existing workspace, to enhance or complement the existing lighting. So, for example, the existing ceiling lighting could be dimmed or switched off when not required and then switched on to provide lower ambient light levels for cleaning.

However, leaving the control of the lighting to individuals has the potential to waste energy, as people will forget to switch the lighting off or down when they no longer need it. Using the latest light source and control technologies, freestanding lighting offers the same levels of control as a fixed lighting installation - such as daylight and occupancy control. These controls can ensure only occupied areas are lit and the lighting levels are automatically adjusted in relation to natural daylight.

As noted earlier, the spatial relationship between the lighting and any sensors used for control is also important and freestanding lighting can also have sensors incorporated into the fitting, with the added advantage that the sensor and the workstation retain their spatial relationship during any relocation. For example, if used with presence detection, the control can be very localised and set to switch lighting off when a single workstation is unoccupied.

In contrast, most occupancy control in open plan offices operates in zones so that the lighting for a group of workstations remains on when only one desk is in use. In addition, any reconfiguration of these controls in a fixed lighting installation can be costly and disruptive.
Freestanding lighting can also be used in conjunction with networked lighting management systems to provide centralised control and monitoring of luminaire performance.

A further cost of ownership benefit is the light sources are located within easy reach, so replacing them does not require specialist access equipment. It's also worth bearing in mind that fewer uplighters are required to light a space, compared to ceiling mounted lighting, resulting in fewer lamps to change, as well as lower power consumption.

When all of these factors are considered, it's clear the freestanding direct/indirect lighting has the potential to deliver the flexibility required for many modern workplaces. Just as importantly, in combining highly efficient light sources and controls with networking capabilities, this innovative lighting also helps to address the sustainability imperatives of most businesses.

For all of these reasons, there are now very strong arguments for considering the use of freestanding lighting from the early design stages of a new build or refurbishment project. It won't be the ideal choice for every situation but it has far greater potential than many people realise.

Most energy efficiency measures have focused on reducing demand at the point of  consumption.  A wealth of new, more efficient drives and motor controllers, low energy lighting and building management systems means the choice for end users seeking to manage their electricity consumption has never been greater explains Alex Rathmell, head of analysis at Power Perfector

Implementing the disparate measures mentioned above and and sustaining the energy savings can be a challenge for energy managers in a complex workplace, with many control-based energy saving measures relying on goodwill or good behaviour from the workforce to keep them effective, and many measures posing the threat of serious disruption to the working day, or complex technical challenges in implementation.

In this context, the effect of poor power quality is often overlooked both as a problem and an opportunity. Until recently, power quality was not considered to be a major source of inefficiency in electrical equipment, as the UK had historically enjoyed a relatively clean power supply compared to many countries. Now though, several factors have conspired to make tackling power quality an attractive energy saving measure, and one of the quickest and easiest wins in the energy manager's tool kit. By cleaning up the supply, energy savings are immediate, permanent and transparent - that is they are achieved without affecting daily operations and without being dependent on the vagaries of human behaviour.

The breakthrough has come with the recognition that the UK's power supply is no longer optimal. Generally when we plug in to the mains supply we don't give a second thought as to how the voltage level might affect the efficiency of the electrical equipment we connect. We know that in the extreme, when the voltage is far too high, light bulbs glow brightly and blow with alarming regularity; whilst with very low voltages, TVs flicker and motors over-heat. Yet there is a broad band in between these extremes where the effects are more subtle, though very significant in terms of energy efficiency and the longevity of equipment.

Following European harmonisation in 1995, the declared electricity supply in the UK became 230V nominal, +10% to -6%, so supply voltage could be anywhere between 216V and 253V depending on local conditions. The European standard covering the UK (EN 50160:2007) now says that the permissible range is 230±10%, making 207V the minimum level at which UK equipment must operate. Most electrical equipment, designed to work for the whole European market, actually has an optimum operating level of 220V, as this was the nominal supply level prior to 1995. Yet in practice over 90% of sites in the UK continue to receive voltage at the historic average level of 242V - and will continue to do so because the design of the supply infrastructure cannot easily be changed.

The grid is designed to accommodate a certain degree of ‘volt drop' across a geographical area, so a small percentage of consumers connected to remote or dense parts of the network are already operating towards the lower end of the permissible range. Unilaterally reducing voltages could therefore take these consumers below the minimum level. The only solution is for the vast majority of users to be supplied at the upper end of the range (an approach that also minimises I2R system losses), so we routinely supply our equipment at over 20V higher than its optimum supply level, wasting huge amounts of energy in operating plant and equipment. In addition to this grid design limitation the connection of various new renewable resources such as wind to comparatively weak points in the grid is expected to have the effect of increasing voltages locally even further. So at a time when an increasing proportion of our equipment needs a lower voltage, our commitment to renewable power may actually elevate voltage  and inadvertently increase energy use.

The only real way to address this issue is to optimise the voltage locally, to ensure site-by-site that energy using equipment is receiving the correct voltage, maximising its efficiency and its lifespan. Of course, customers with their own HV transformer have a certain degree of control - they can typically adjust their voltage by up to ±5% by altering their transformer's tap settings - but this doesn't constitute optimisation in any meaningful sense of the word. Reducing a 242V supply by 5% gives us 230V, still 10V higher than the optimum level so there is a substantial missed opportunity for savings.

Just as average voltage levels remain high or creep upwards, other factors are contributing to a deteriorating power quality picture in the UK to which engineers are having to adjust. As well as potentially increasing average voltage levels, the introduction of diverse but intermittent generating sources into the mix leads to more switching on the grid, increasing incidents of ‘transient' voltages and other distortions that can damage sensitive electronic equipment and cause nuisance tripping. Levels of harmonic distortion are also at historically high levels, not least due to the ongoing replacement of older linear equipment with more efficient non-linear loads such as high frequency electronic ballast lighting, and huge numbers of inverter drives. These technologies should be applauded, but raising levels of harmonic distortion dramatically increases losses in a power system.

However these new realities do not mean tackling the UK's most prevalent power quality issues need be a formidable technical challenge. While serious or unusual problems should always be dealt with using bespoke solutions, a ‘common sense' approach to power quality can be applied to any site where energy savings are needed. This approach is to optimise the voltage at the source of the building's power supply, to ensure it is well matched to the electrical equipment, while taking the opportunity to protect the site from grid-borne transient distortions and reduce losses by filtering harmonic distortion and improving power factor.

Fortunately, these twin pressures of deteriorating power quality and the need to improve energy efficiency have been experienced before - in Japan, nearly twenty years ago.  At the time, Japan had the same pressures on fuel and energy prices that we have today, as they have to import all of their fuel requirements and rely on expensive nuclear generation. As a result attention was focused on the incoming supply to a building, on its voltage level and quality, as a way of achieving further incremental energy savings in a country where the need for efficiency is deeply embedded in working culture. Technology known as ‘Voltage Power Optimisation' (or ‘VPO') was developed specifically to save energy by optimising supply quality, dealing with the most prevalent power quality problems in a device that can be fitted ubiquitously, as a permanent part of every site's electrical supply infrastructure. The technology must add neither risk nor additional energy use to the site, so total reliability and extremely high efficiency are key elements of the design of VPO equipment. These requirements, as well as the need for additional power quality improvements, mean that conventional automatic voltage regulator technology with its reliance on moving parts and electronic control systems is not appropriate for at-source applications - the development of VPO represents a new approach.

There is an even greater opportunity for VPO technology in the UK than in its home country of Japan, because the voltage supply parameters there are 90-110V, which is adjusted by -2%, -4% and -6% by the implementation of VPO. This approach - essentially correcting for local problems on the grid and targeting the voltage at the optimum level for equipment operation - has saved millions over a period of many years. In the UK, meanwhile, our institutional problem with over-voltage means that not only can a higher proportion of sites benefit from optimisation, but the savings delivered in each case are substantially higher than those seen in Japan. Even on an efficient site with modern lighting and inverters fitted to its motors, savings of 4-8% are typical, while a site with a high proportion of older equipment is likely to experience 10-15% savings in many cases. This means the technology will pay for itself in 2-4 years, making it a popular choice for energy managers confronted with CRCEES obligations and the looming threat of widely-predicted energy price increases.
Optimising power supply at source is a way of harvesting a number of different opportunities for savings across a diverse range of plant and equipment. The savings seen on the main meter are an aggregate of a range of different effects - some dramatic, some subtle - across the whole site. Technically, most savings are realised in induction motors and lighting equipment. Optimising the voltage to a motor essentially means giving it a supply that is appropriate for its loading point. An average motor is both over-specified (and therefore lightly loaded) and, in the UK at least, supplied at an over-voltage. So losses can be reduced by bringing the site voltage to a lower level without affecting the motor's operation. Lighting benefits by being returned to its 'design' voltage and brightness, so both current and power is reduced and lamp life is increased substantially. In fact, almost all equipment will benefit from extended lifespan if provided with an optimised power supply, adding a tangible maintenance cost reduction benefit to the available savings.

Increasingly, energy managers are finding that addressing power quality issues at source is one of the highest performing and lowest impact tools at their disposal, and the take up by major retail, governmental and public sector organisations confirm that VPO is among the most attractive energy saving measures on the market. This reflects the growing realisation that poor power quality is wasteful, and its correction presents an invaluable opportunity for energy savings.

The election outcome has done nothing to appease our grumpy old man's disdain for politicians when it comes to our energy supplies

Well, we have a new prime minister. Well, sort of at any rate. My fears of a hung parliament were unfortunately fulfilled and when I signed off my last column stating "the jury's still out", little did I know that would remain the case this month!

There is a remarkable dichotomy presented by the coalition of ConLibDem. On the one hand Cameron's pledge to reduce energy usage by 10% within Government buildings will satisfy Clegg's desire for greenery. On the other, new secretary of state for energy and climate change, the LibDem's Chris Huhne, is going to have to compromise on of his fundamental political beliefs in accepting nuclear power, since Cameron intends to pursue the building of 10 new nuclear stations agreed last November.

Resisting the temptation to suggest a very popular way of reducing harmful hot air emissions from government, there is a very serious point to my apparent satire.

Chris Huhne has already outlined his priorities: "Climate change is the greatest threat to our common future. We have a very short period of time to tackle the problem before it becomes irreversible and out of control.

"A lot of progress has been made, but we must now go further, faster and turn targets into real change.

"This is a coalition to provide strong and stable government for this country. The benefits of the low carbon economy are agreed between both parties, this is a priority agenda common to both manifestos.

"Together we have the opportunity to make this the greenest government in our history. And to put energy security, for too long a second order issue, at the heart of the UK's national security strategy.

"I intend to make decisions put off for too long to fundamentally change how we supply and use energy in Britain.

"To make it far easier for people to make their homes more energy efficient to reduce wasted energy and cut their bills.

"To give the power industry the confidence it needs to invest in low carbon energy projects.

"To create jobs and growth right across the low carbon economy.

"And to use every influence we have internationally to get a global deal to tackle climate change."

All are laudable points, all important issues and all are excellent statements. But, population growth, coupled with continually growing demand for power from modern equipment, quickly negates the most ambitious energy savings targets. So how do we cope with that?

The LibDem party will undoubtedly maintain its opposition to nuclear power while permitting the government to pass laws that make new nuclear construction possible. LibDem members have said they will abstain in parliamentary votes.

Despite a brave face from the utility companies, analysts remained unconvinced that the agreement will provide stability for investors.

Oliver Dancel, senior energy and utilities analyst at Datamonitor, told the Daily Telegraph: "The issue is how utilities such as EdF Energy and E.ON will react. Such political uncertainties will inevitably delay the process of delivering the new investment in power generation capacity the UK so badly needs. Investors will be watching the coalition closely for signs of stability."

Far from welcoming a refreshing new political regime and a new breed of politicians, I for one, will be keeping a very close eye on the decision making process and, more importantly, its delivery.

A new harmonised European standard EN 60034-30:2009 is to replace the old  voluntary Eff classes. The first phase is now a year away so machine designers need to be conversant with the regulations now. The good news is the changes need not cost much more, and for the end user and the environment the results are entirely positive

The new regulations apply to 3-phase asynchronous motors in a power range 0.75 to 375kW in 2,4 and 6 pole designs, basically the vast majority of motors and used in the construction of machinery. There are certain exceptions, for example 8 pole motors, motors that are an inseparable part of a machine and those with supply voltage over 1000V.

However, the scope is predicted by the UK Government Department of the Environment to be sufficient to arrest the current increase in energy and used by electric motors. This is no mean feat bearing in mind the massive number of motors in service and the fact they consume nearly 40% of the nation's energy.

Three new energy efficiency bands are defined:
IE1    for motors of Standard Efficiency, equivalent toEff2
IE2    for motors of High Efficiency, equivalent to Eff1
IE3    for motors of Premium Efficiency, no previous equivalent

Looking further ahead it is anticipated an ever higher level of efficiency IE4 will be introduced. The actual limits of these three efficiency bands vary according to motor power. As an example in round figures, the minimum efficiency for a 7.5kW motor is 85% at IE1, 88% at IE2 and 92% at IE3.

There is a phased introduction of the new regulations beginning in 2011:

16 June 2011 -  motors must meet the IE2 efficiency level as a minimum

1 January 2015 -  motors from 7.5 to 375 kW must meet the higher IE3  efficiency level, or must be ‘equipped' with an inverter variable speed drive

1 January 2017 -  the 2015 regulations are extended down to motors of 0.75kW

The regulations are based around the concept of motors that are ‘placed on the market'. This means motors delivered from motor manufacturers and their subsidiaries, including replacements for existing motors. Old stock at independent distributors or at machine manufacturers can still be sold. Repairing and rewinding old motors is permissible.

Thus any new machine or old machine requiring a replacement electric motor will require compliance with the new regulations. For the end user this is almost invariably a benefit. Over the lifetime of an electric motor, energy costs amount to about 97% of the total costs of ownership. Therefore a 2-3% gain in efficiency can achieve big savings in the long term. Based on 8000 hours per year, stepping up an efficiency level can give payback times on the extra investment of about 2 years. As a simple guide, if a motor is used for 2000 hours a year or more, an advice is to buy premium efficiency or high efficiency with inverter drive now.

There are strict requirements for labelling of the motor rating plate. From June 2011 the following information must be shown on the rating plate and the motor documentation: lowest efficiency at 100%, 75% and 50% rated load, the efficiency level (IE2 or IE3) and the year of manufacture.

As stated above, from 2015 IE2 motors equipped with a frequency inverter can be used instead of IE3 premium efficiency motors. This is an attractive alternative and the IE2 + inverter combination will generally yield greater savings compared to IE3 if variable speed is required. There is no expectation the inverter will be integrated into the motor, although that is possible, and it is expected many customers will purchase motors and inverters from different sources. Documentation requirements are not yet defined, but it would seem likely a degree of self-certification will apply. 

As the efficiency levels of motors increase, so does the cost as a result of increased material and manufacturing costs. The increase in costs does depend on frame size. Changing from IE1 to IE2 currently brings in a price premium of 20-30%, less on larger frame sizes, but as production volumes increase this is likely to fall to 10 to 20%. The premium to step up to IE3 is likely to be a little less. However, adding more copper to meet higher efficiency levels can also result in changing dimensions. Often the motor length will increase. In a minority of cases the motor frame size may increase, for example from IEC90 to IEC100. In turn this may cause problems on existing machine designs with replacement motors.

Many people would say the new regulations and efficiency bands are long overdue.  We are playing catch-up with countries like the USA and Australia. With the first phase a year away, we have time to take the necessary steps for the changes. Increases in costs are modest compared with the lifetime costs for motors. The big winners are the end users with lower energy costs and the environment as a whole.

Lenze is well positioned to offer high efficiency products and packages. Right now, as well as IE2 motors there is a range of IE2 geared motors available up to 45kW. As a manufacturer of frequency inverters, Lenze can offer packages of motor/geared motor and inverter that are IE3 equivalent. Other products, such as the MF motor range, can deliver better than IE2 efficiency and 30%  savings at part loads, also regenerative braking units that can return excess energy to the mains.

The standard IEC 61850 [1] covers the communication in utility automation systems. More  and more substations use a communication system according to this standard incorporating GOOSE and Sampled Values. This article describes Omicron's new test set, CMC 850, which was developed to fulfill the requirements of customers working in pure IEC 61850 environments

CMC 850
The CMC 850 is the first test set dedicated to IEC 61850. It focuses on the described real time communications utilising Goose and sampled values. The device is controlled by the well proven Omicron Test Universe software. Additional features can be accessed through a new web interface.

The device was developed for the IEC 61850 standard, working without classical secondary values. The result is a small and light weight device which is compact and easy to carry having a width of just 80 mm and a weight of only 1.7 kg. Conventional I/Os and analog outputs are not available.

The capabilities of CMC 850 regarding IEC 61850 are the same as their ‘big brothers' CMC 256-6, CMC 256plus, CMC 353, and CMC 356:

The CMC 850 has the capabilities of simulation and subscription of up to 360 data attributes up to 128 Goose messages, and the generation of up to three sampled values streams (one stream contains 4 currents and 4 voltages).

The supported sampled values version and more specifically the option with 80 samples per cycle is in accordance with the implementation guideline of the UCA International Users Group [2], (widely known as "9 2LE").

Additional Features
The device provides additional built-in functionality, which cannot be found in other CMC test sets. These functions are accessed with a normal web browser. One feature is the visualisation of received sampled values in a multimeter or oscilloscope view.

Subscribed sampled values are used to calculate the phasors, which are then provided as synchro¬phasors according to IEEE C37.118 [2]. Recorded network traffic (in PCAP-format) can be played back through the device.

Time Synchronisation
Time synchronisation is an important issue when dealing with sampled values. The CMC 850 is delivered with the CMIRIG-B interface which allows synchronization to IRIG-B or a pulse-per-second (PPS) signal. Time stamping of Goose messages and sampled values is made possible through the use of Net¬work Time Protocol (NTP) or Precision Time Proto¬col (PTP) according to IEEE 1588-2002, V1).

Segregation of Networks
The CMC 850 is equipped with two independent Ethernet-Ports.
Each of these ports can be used for controlling the test set with a local PC, or for sending/receiving Goose and/or sampled values. This allows maximum flexibility in the configuration and a segregation of IEC 61850 data combined with the control protocol for the test set.

Applications
The CMC 850 test set is perfect for use in the IEC 61850 environment. It is particularly suitable for use in the development of intelligent electronic devices (IEDs) and for factory and site acceptance testing. The device is also ideal for demonstrations of IEC 61850 IEDs and for training purposes.

Summary
Omicron was the first vendor to provide testing solutions for IEC 61850. This device, equipped for current and future testing in the IEC 61850 environment, is the result of vast experience, technical skill and collaboration with international standardisation committees.

Omicron

Tel: 01785 251 000

This email address is being protected from spambots. You need JavaScript enabled to view it.

http://www.omicron.at/

 

Specifiers must assess enclosure construction before specifying products as the incorrect  choice can lead to significant and costly consequences. They should also make sure they fully understand the system of IP ratings, to avoid incorrect choices and spending more money than necessary. here, Darren Hodson from Schneider Electric explains the system of enclosure ratings, discusses the differing materials available and highlights one of today's most common misconceptions surrounding the ratings standards - IP69K

The various enclosure materials available have their strengths and weaknesses and in order to specify the most appropriate material, these must be fully understood. In addition, the importance of the right quality enclosure is critical.  The role of an enclosure is to protect valuable electrical components and personnel and it just doesn't make sense to save a few pounds by purchasing an inferior product to protect high value systems.  A substandard enclosure could result in leaks, damage to equipment, and possibly even become a hazard to the public.  If this happens not only is the user faced with the cost of replacing the enclosure, there is also the cost of changing any damaged components, downtime and possible litigation.

It is critical the same level of time and investment goes into choosing the right quality enclosure, in order to reflect the time and money spent in developing the system it contains and the system(s) it is connected to. Choosing the right material for the job is also an important consideration.  Buying a high quality enclosure, but in the wrong material, can be a costly mistake. 

Depending upon the application and the preference of the customer, there are three common materials which enclosures are manufactured from: mild steel, stainless steel and GRP. But regardless of the material used, each enclosure should be chosen to suit the specific application they are intended for and this includes having the appropriate IP rating. IP ratings are defined in the IEC 60529 standard for degrees of protection provided by enclosures, published in the UK as BS EN 60529.

The degrees of protection are specified by the letters IP, followed by two or more digits. The first digit (1 to 6) depends on the protection given by the enclosure to equipment within it against the ingress of objects, and also the protection of persons against contact with live parts of equipment within the enclosure. The second digit (1 to 8) relates to the protection of equipment against the harmful ingress of water. Either digit can be replaced by ‘X' for an unspecified condition.

Optional supplementary letters can be used to specify only the protection of persons against access to hazardous parts, and to stipulate special conditions, such as use for high-voltage apparatus or under specified weather conditions.

In general, a higher number represents better protection, although specifiers should be aware this isn't always a guarantee, as sometimes an enclosure might, for example, pass the tests for IP67 but not to a lower rating such as IP65.

It is important specifiers fully understand the conditions of use for an enclosure, as simply specifying a high IP rating does not necessarily mean it is right for the job. The designations refer to the ability of the enclosure to pass the tests under controlled conditions, not to its ability to withstand influences such as weather, sunlight, corrosion, or extremes of temperature. A product can meet the highest level for protection against ingress of water, yet be subject to rusting, so customers must make clear what they are actually expecting from an enclosure rather than relying solely on an IP rating.

In addition to IEC (BS EN) 60529 there are two other standards widely used for enclosures; IEC (BS EN) 62262 ‘Degrees of protection provided by enclosures for electrical equipment against external mechanical impacts (IK code)' and IEC (BS EN) 62208 ‘Empty enclosures for low-voltage switchgear and control gear assemblies - general requirements.' BS EN 62262 uses the letters IK followed by the numerals 00 to 10 to specify the enclosure's ability to withstand mechanical shock including direct impact.

These ratings are used across all materials including mild steel -the UK's most popular choice. This type of enclosure is suitable for most indoor applications. With IP ratings up to IP66 and a high IK rating, it is robust and strong in many environments. The fact that it is easily modified is another reason why it has remained a popular choice for so long. However, specifiers are gradually realising its weaknesses. Mild steel has poor anticorrosion properties if the material is not treated, and this treatment is usually expensive. In addition, cut-outs made after painting must also be protected, adding yet a further cost.

As an enclosure material mild steel still has its place. For general purpose enclosures, either indoors or in industrial and commercial premises, it is a cost effective solution but the fact it corrodes so quickly makes it an unsuitable choice for any external applications.

Stainless steel has been a popular material choice for decades, typically used within the food manufacturing, food processing and pharmaceutical industries as well as for most external applications. It provides the same benefits as a mild steel enclosure but with greater longevity in aggressive environments.  It is also rust resistant, however depending on the grade and the environmental conditions, tarnishing and corrosion can occur. Stainless steel also has its own natural finish and so requires no further treatment.

GRP is best suited to outdoor applications as it does not corrode in damp/wet conditions, even when exposed to sea salt. It also offers excellent protection against UV rays and therefore it won't discolour. Being an insulator it offers extra peace of mind on public access sites and so GRP is fast becoming a major competitor to steel with its insulation, strength and corrosion resisting properties over a temperature range from -50oC to 150oC.

GRP enclosures are designed for the wide variety of aggressive applications in which they are used. In addition to the material, which is double insulated, self-extinguishing and halogen free, there are a number of anti-vandal features which make unauthorised access difficult. The list of industries that now accept GRP enclosures is growing and includes security, airports, highways, rail, utilities, telecoms and agriculture.

It is also important to remember, especially when considering harsh environments, high IP levels are not necessarily an indication of a product being weatherproof. Other design features such as canopies also contribute to the enclosure providing the correct level of protection.

IP ratings are invaluable in ensuring enclosures meet the correct standard however it is not always straight forward, as highlighted by one of today's most common misconceptions - requests for enclosures rated IP69K. At first sight, when you consider the rules for IP codes there is no such thing, since this rating is not mentioned in any of the standards mentioned above. In fact it stems from a German national standard developed for use specifically in the automotive industry.

DIN 40050-9 adds to the IEC 60529 rating system with an IP69K rating for high-pressure and high-temperature wash-down applications. The IP69K test specification was initially developed for electronic equipment on road vehicles, but has also been used in other areas such as the food industry, where the use of pressure washers is common.

This standard is purely a German national one and currently has no real meaning in the UK or other countries, as it doesn't feature as part of a British or International standard. A project is now underway to incorporate its requirements into IEC 60529 but initial attempts by various test houses found the test equipment and procedures were not precisely defined by the DIN standard. This means they do not give the same result when performed by different test houses, and so cannot be compared. Some research has resulted in a proposal to modify IEC 60529 to include the designation IPX9, but this is still at an early stage, and needs more work before it can be published as an amendment to the standard.

In the meantime buyers of enclosures should be aware that ‘IP69K' products from different manufacturers may differ, and might not even pass the tests for IPX5. They should also remember that even the IEC 60529 tests are fairly short, up to 30 minutes for IPX7, although longer immersion can be agreed as part of IPX8. As a result they do not define the enclosure's ability to withstand long-term influences such as weather conditions. It is also often forgotten the ‘water ingress' tests do not specify that no water must enter; they allow water to enter but not in quantities that are considered to be ‘hazardous', which of course cannot be determined without knowing what apparatus will be within the enclosure.

Today's enclosures offer a wide choice of materials and the breadth of products available is always expanding but specifiers and designers should remember that correct material specification is vital in achieving product longevity. And it is impossible not just to choose an enclosure with the highest IP rating and expect it to do any job, in any environment. Specifiers need to carefully assess the conditions of use and prescribe the IP rating that is most appropriate and importantly one that is recognised by IEC or British Standards, as well as choosing the appropriate material for their enclosures.

Machine builders help customers connect manufacturing and IT by using information-enabled machines explains Andrew Smith, commercial engineering team leader for architecture and software, Rockwell Automation

As manufacturers converge data between the plant floor and business office, machines that leverage the power of these domains have become a machine builder's competitive advantage. Information-enabled machines arm manufacturers with a valuable resource for gaining critical operational insight they need in today's knowledge-based business environment.

While helping to differentiate machine builders in the marketplace, information-enabled machines have another advantage: they help machine builders reduce total cost to design, develop and deliver those machines to the market. As the economy has cooled, demand for information-enabled machines has heated up. Why?

Machines with embedded intelligence offer an innovative way to wring more productivity out of the manufacturing operation. That's because these machines generate data and diagnostics that leads to meaningful analysis. That analysis helps control engineers precisely identify how to improve their processes.

Industry standards help
Fortunately for machine builders, industry standards such as EtherNet/IP have made building these sophisticated machines easier than ever. The EtherNet/IP protocol allows users to control, configure and collect information over the same network while still having the ability to support standard Ethernet functions such as e-mail, web page browsing and data sharing.

With such broad capabilities and performance, Ether- Net/IP can serve the functions of multiple network levels. This converged network infrastructure simplifies a machine's design, and in turn helps machine builders lower their design costs.

The savings are even greater for machine builders that pair EtherNet/IP capabilities with controllers that have advanced text string handling instructions. With supporting hardware, EtherNet/IP-enabled controllers can initiate e-mails to multiple addresses to deliver reports that maintenance personnel can use. For example, maintenance can check alarms, provide manufacturing proficiency data to management or deliver machine diagnostic data to the OEM.

This deep understanding, along with remote access capabilities, helps keep machines running. Embedding intelligence-gathering devices into machines helps machine builders provide customers with self-diagnostic equipment that can predict and prevent failures. This improves productivity and can reduce repair costs.

Some machine builders provide an overall equipment effectiveness (OEE) report and other advanced information displays via the human-machine interface (HMI), giving operators instant insight to these diagnostics. In addition, the end user can relay machine condition information back to the machine builder for value-added monitoring  and analysis services. Technicians can then securely connect to the machine to monitor critical parameters and take action before a machine fails.

Savings beyond the machine
Machine builders traditionally designed equipment with a focus on meeting the needs of the controls engineer. However, they also need to consider the needs of IT professionals. At Rockwell Automation we have developed tools, technologies and resources to help OEMs both address and facilitate this top-floor to shop-floor integration. New products help machine builders manage real-time information flow by reducing network latency and jitter. Modular managed switches can now address the network convergence activities by offering features for both IT professionals and control engineers. Fixed managed switches can also give users cost-effective control over their Ethernet/IP network, which can work especially well for applications with small or highly distributed network devices or devices connecting to the controller.

Achieving high performance
Information-enabled machines are essential for giving operators and managers the insight they need to technologies and resources, machine builders can reduce their overall cost to design, develop and deliver these sought-after machines. Machines that effectively bridge the gap between the shop floor and the top floor ultimately help OEMs meet customer demands for high-performance machines.

Stephen Trotter, division head of ABB Power Systems UK, explains how hybrid switchgear  modules that combine the virtues of AIS and GIS technology can offer greater flexibility for substation design

The term ‘hybrid' refers to the combination of both conventional air insulated switchgear (AIS) and the newer metal-clad gas insulated (GIS) switchgear. This hybrid solution, as found in ABB's Pass MO design - rated up to 170 kV, uses existing, tried and trusted GIS components together with a conventional and extremely reliable AIS bus to connect the various hybrid modules. All the necessary substation switchgear bay functions, including a circuit breaker, one or more combined disconnector/earthing switches, bushings for connection to single or double busbar systems and a current transformer are integrated in one compact module, eliminating the need for separate pieces of equipment for each function.

Hybrid advantages
The advantages of the hybrid switchgear design include:
- AIS busbar: The AIS busbar is relatively inexpensive while offering proven reliability.
- All live contacts in SF6: Experience has shown AIS disconnector switch contacts require relatively high levels of maintenance, while experience with GIS is exactly the opposite. The use of SF6 technology makes the hybrid switchgear virtually maintenance free, this combines with a high level of reliability to ensure a lower global life cycle cost.
- Fewer switching elements: Use of GIS technology allows rationalisation of switching elements.
- Factory pre-assembled and tested: The hybrid modules are fully pre-assembled and tested in the factory. This ensures a higher quality of finished bay than if it is assembled under site conditions, minimises installation time on site - typically two days per bay, reduces the possibility of delay due to adverse site conditions and there is less need for skilled resources on site.
- Monitoring and on-line diagnostics: The integrated nature of the plant facilitates the use of electronic monitoring and on-line remote diagnostics.
- Substation modularisation: A modular approach to substation design offers cost and time savings during the design and construction phases. The use of standardized components reduces the number of possible variations and hence the risk of design errors. More predictable costs also offers a higher level of confidence in the project estimation process.
- Space saving and reduced civil works: The hybrid design can save up to 70% of the space normally required for a conventional AIS substation, while also reducing the need for civil works such as foundations, steelwork and cable trenching operations
- Combined disconnector/earthing switch: Pass MO is equipped with a combined disconnector/earthing switch. The mechanism has a minimal number of mechanical components and is intrinsically reliable and maintenance-free.
- Circuit breaker: The Pass MO circuit breaker is a single pressure interrupter that operates by means of the well known selfblast principle. The energy for interrupting currents is partly supplied by the arc itself, this reduces the energy the operating mechanism needs to provide by around 50% compared with a conventional puffer type circuit breaker.
- Versatility: The Pass MO range offers a series of modules for HV substations including: single bus bar (SBB); double bus bar (DBB); double circuit breaker (DCB). It can also be installed as a high voltage bay on a mobile truck for use in emergencies or if work has to be carried out on existing HV bays.
- Transportation: The Pass MO fits into a standard truck container and does not require any packaging. No special arrangements are needed for shipping and transportation, and once on site just a simple 30° rotation of the outer poles is needed for the final layout.

Tight fit for Breamish Street substation
Well over 2,000 Pass MO bays have been installed worldwide. Following its approval by the ENA (Energy Networks Association) one of the first UK projects to feature the range was CE Electrics UK's new 66/11 kV Breamish Street substation on a brownfield, urban site in Newcastle-upon-Tyne.

The new primary substation is helping CE Electric UK to deliver an additional 18 MVA of firm capacity to meet the growing demand for additional power, and need for load transfer, created by the significant urban redevelopment programmes on the north bank of the River Tyne. The restricted space available presented a particular technical challenge, since the Breamish Street site is not only compact in size, it is also hemmed in on all four sides by a hotel, a pharmacy, a residents association and the 18th century St Ann's church.

The space-saving capability of the design has been utilised to construct a new substation comprising two 66/11 kV 15/30 MVA CER transformers, a 66 kV in/out unit and a 13 panel 11 kV switchboard. A 66 kV feeder unit has also been installed at Fossway, the closest CE Electric UK substation.

Providing vital construction space at Reading
Hybrid switchgear has also provided an innovative interim solution for the new Scottish and Southern Energy (SSE) 132 kV indoor GIS substation at Reading, currently under construction by an ABB and Balfour Beatty consortium. The site presented a particular challenge as it was already completely full with time expired AIS switchgear that needed to remain in service until the circuits could be transferred to the new substation.

At first, it appeared the only possibility would be to extend the site onto the local, heavily wooded, green space to offer the additional room needed for the construction of the new indoor GIS building. However, extending the site would have involved considerable planning time and expense and significant project delays.

An innovative alternative was found by using ABB switchgear as a temporary measure to provide additional space to enable the new GIS building to be built within the existing site footprint. Firstly, ABB dismantled the generator circuit breakers that used to serve the old North Earley power station, which was demolished some years ago. This freed up just enough space to install the Pass MO modules to take over the operation of the AIS circuits at the far end of the site. This enabled the old AIS switchgear to be dismantled to make room for the new GIS substation. After all the circuits have been transferred to the new substation the Pass MO modules will be removed.

        
                     

Jim Wallace of Seaward, explains how advances in test technology have increased the range of test instrument options available to contractors

For contractors involved in electrical testing there has never been a wider choice of test instruments available.

In recent years the instrumentation industry has been at the forefront of innovation and technical advances. These changes have been made in recognition of the situation for electrical companies, particularly during difficult economic conditions, the challenge is to balance the provision of efficient, high quality test services with a competitive price tag and value for money offering.

The test companies that flourish will be those that combine a fast and effective service that does not compromise the quality of testing undertaken - and who can build on existing customer relationships.
In fact customer service and satisfaction levels have become a crucial area for electrical test companies. With less work around existing relationships become even more important. It follows that an ability to enhance existing customer services through the provision of a cost-effective and added-value test service can do much to both reinforce a company's reputation and maintain a positive profile with influential prospects.

In addition, as well as a wide variety of testers available, the ability to provide a seamless link between test instruments used in the field and central test record systems that produce test certification and other reports also takes on even greater importance.

The good news for large and small contractors is advances in test instrumentation mean a range of options are available to meet specific test needs - and budgets - for periodic electrical installation testing or portable appliance testing.

In 17th edition testing
The HSE's Guidance Note GS38 provides guidance to electrically competent people involved in electrical testing, diagnosis and repair. The note identifies three main test instrument categories - those that detect voltage, those that measure voltages and those that measure current, resistance and (occasionally) inductance and capacitance.

The first named forms an essential part of the procedure for proving a system dead before starting work, whilst the other categories are more concerned with commissioning and testing procedures and fault finding.

Guidance note GS38 provides details of the risks associated with the use of unsatisfactory test equipment and includes a list of safety precautions and requirements all professional electricians should be aware of.

However, in terms of selecting appropriate 17th Edition test instruments, electrical contractors are broadly faced with a choice between ‘multifunction/combination' testers or single application specific testers.

As the name implies the latter are designed to carry out one specific function - RCD testing, insulation, earth resistance etc - and the ‘all in one' type testers are single units designed to carry out a wide range of tests including earth loop, insulation resistance, continuity, RCDs etc.

Choice invariably depends on the scope of work to be carried out, but increasingly it is the multifunction testers that have become the preferred tools of the trade for those involved in 17th Edition testing. This is for both practical reasons, in terms of using one meter constantly rather than swapping and changing between testers, and also for budget considerations - buying, maintaining and calibrating one combination tester is invariably cheaper than buying three separate ones.

Multifunction 17th Edition testers carry out the required circuit tests and display the test reading for transfer onto the test certificate manually or alternatively, readings can be recorded on a PDA and transferred to a desktop application for certificate printing. Some testers are also linked with smart phone and portable laptop applications which work in the same way by gathering test data collected in the field for subsequent transfer onto a master certificate.

The latest generation 17th Edition testers eliminate the use of intermediary devices by storing a replica of the test certificate within the tester so test data can be automatically incorporated onto the certificate as testing is undertaken.

In this way the instrument combines the functions of a multifunction test instrument and data logger. When inspection and testing is complete, the certificate held inside the tester can be transferred to accompanying PC software for the completion and print out of formal certificates.

As a result the time consuming (and therefore costly) practice of recording results on paper, a dummy certificate or a PDA is avoided. In addition, because the tester warns the user if any certificate fields appear  incomplete or invalid, verification of data can be carried out on site immediately and without return visits.

Recently the concept on ‘on board certification' in testers has been extended with additional features aimed at large testing organisations or the testing of large premises.

For example, the moist advanced 17th Edition testers now have the ability to upload certificates generated on a PC into multiple testers. This is particularly useful in situations where a number of test personnel might be working on the same large installation, such as a hospital development or shopping mall and enables specific test work to be allocated to a number of engineers very easily.
Once testing has been undertaken, the software enables test results downloaded separately from different testers to be merged into a single certificate for the premises concerned.

Another new feature is the ability to ‘clone' certificates from an existing master document. This allows the user to select an existing certificate and use this as a template to create multiple certificates for identical or similar electrical installations.

The cloned certificates will contain all of the distribution boards and circuit details held in the original and therefore represents an easy way of generating certificates for, say, 20 or more  houses on a street which all have the same electrical configuration.

In these combined testing and certification testers, all data transfer between the PC and the instrument can be achieved easily using Bluetooth connectivity. This means a certificate can be uploaded to the tester, the required test and inspection carried out and the information downloaded to a PC and the final certificate printed directly onto pre-printed NICEIC, ECA, ECA Select or Napit stationery.

With such a wide range of test instruments and accessories to choose from, electricians and contractors involved in 17th Edition electrical testing can be sure the right test package solution is available to meet their specific needs and budget.

In recent years substantial technical development has gone into the development of new test instrumentation so the ‘tester' can now be used in a much more effective manner - improving operational efficiencies, adding value to the test process and enhancing customer relationships.

IEC 61850, the new standard for substation data networks, is creating a lot of interest and  excitement. It's also creating more than a few challenges, says Romain Douib of Megger, not least for substation control engineers who spend their lives creating and working on interlocking schemes

One of the biggest challenges substation control engineers face, is not how to implement interlocking schemes based on IEC 61850, but how to test them. The problem is particularly acute, because at present IEC 61850 is being more widely used for interlocking than it is in protection applications.
Of course, options do exist for testing IEC 61850 interlocking schemes. However, these almost always involve the use of protective relay test set that supports IEC 61850. This approach, however, is far from ideal. The first concern is that, in most cases, control engineers are not protection engineers. They are unlikely, therefore, to be familiar with the operating a protective relay test set. They could, of course, learn, but that's a pretty steep learning curve for something that is not central to their work.
Another issue is protective relay test sets are necessarily costly, since they incorporate high-performance precision amplifiers and other elements that are expensive to develop and produce. Yet these are not needed for testing interlocking schemes, so using a relay test set in this application is not only overkill, it also needlessly ties up expensive capital equipment.

It's clear there is a pressing need for a reasonably priced instrument that is simple to use and provides all of the facilities needed for testing IEC 61850 interlocking schemes, but does not incorporate the expensive extras needed for protective relay testing.

It's not difficult, in principle at least, to imagine how such a test set would work. First of all, it would monitor the Goose messages IEC 61850 installations use to communicate and it would convert them to the ordinary type of on/off binary signal that control engineers are used to working with in non-networked installations.

The test set would also be capable of working in the opposite direction. That is, it should take signals from ordinary contacts and convert them into appropriate Goose messages. In effect, a test set of this kind is simply an interface between the Goose messages on the bus and the electromechanical world of the control engineer.

Of course, there's rather more to be considered than this very basic overview initially suggests. For example, the conversion between Goose messages and binary signals must be fast enough so as not to materially affect the timing of the interlocking system. In practice, a conversion time of less than a millisecond, which is achievable with careful design, will be fast enough to satisfy the most demanding of requirements.

Next, it is clearly necessary to be able to associate particular Goose messages with specific inputs and outputs on the test set. This is best accomplished with software but, if it is to be intuitive and easy to work with, the software needs to be carefully designed. Further refinements can also be envisaged. For example, LEDs that provide instant visual confirmation of the state of the instruments binary inputs and outputs would be an important benefit for users.

The ideas mentioned in this article have driven the development of Megger's new Goose Message Interface.. This embodies a number of unique technical features for which patents are pending, and offers the most efficient and cost-effective solution currently available to the challenge of testing IEC 61850-based substation interlocking schemes.

That is, however, by no means the limit of the capabilities of the Goose Message Interface. While it may not be particularly interesting to control engineers, the unit can also be used to adapt a conventional protection relay test set so that it can be used to test IEC 61850 protection schemes. This is a big benefit for users that already have protection relay test sets - whether they are units supplied by Megger or by others - as it is offers a very straightforward and cost-effective upgrade path.
It also creates an attractive option for consultants and smaller organisations who can now purchase a Goose Message Interface and a modestly priced relay test set, to cover all their relay and interlocking test requirements for both conventional and IEC 61850 schemes.

Equipment that allows convenient and dependable testing of IEC 61850 interlocking schemes has, until now, been difficult or even impossible to find. This situation has now been addressed by Megger's Goose Message Interface, an instrument that provides the added bonus of facilitating the testing of IEC 61850 protection schemes.

Premier League footballer and World Cup hopeful Gary Neville's recent application for a new luxury eco-home complex incorporates cutting edge intelligent building automation technology alongside impressive green credentials

Neville's new eco-mansion - dubbed the ‘teletubby' house in the press due to its setting in the West Pennine hillside - spreads over 8,000 sq ft and features solar panels, a wind turbine and a ground source heat pump.

High-end developments like Gary Neville's can disguise the fact that intelligent building automation has entered the mainstream. They are no longer the preserve of the rich and famous (and WAGs).

Core intelligent building automation functions such as lighting or climate control are becoming the norm. Customised options are limited only by the size of the client's imagination and bank account.

The average householder in the UK now expects a level of sophistication in building automation undreamed of 10 years ago.

Buildings that are energy efficiently designed are becoming increasingly popular. Most modern buildings incorporate some form of Intelligent Building Technology (IBT) ranging from automatic lighting and climate control to door entry and security systems.

Intelligent Building Technologies

With the increasing demand for ‘green' buildings, Intelligent Building Technology systems can contribute to significant energy savings over time and offer tangible benefits to end users - both residential and commercial - and also represent added value to electrical contractors in terms of the work involved.

The operation of heating, lighting and blinds among others can be aligned with external climate conditions or adjusted by an interface to pre-set levels.

For example, lighting can be altered depending on the amount of natural light detected or people present in the building. Heating, cooling and ventilation can be measured by temperature sensors and adjustments made where necessary.

Cabling

Despite the extended functionality of these intelligent building technologies (IBTs) the wiring systems used are actually remarkably simple.

Neville's eco-mansion plans to draw energy from a range of wind turbines and solar panels, with any extra energy being fed back into the national grid - further reducing its carbon footprint.

As part of the growth in renewable energy sources, the demand for specialist cables to meet this need has increased as well. While once again the cables used to link solar panels are actually very simple - the installations can often be in hostile environments.

UV light for example can be extremely damaging to conventional PVC cables, breaking down the standard insulation over time. The FSC range of solar panel or photovoltaic (PV) cables are designed to work in extreme conditions with a temperature range or up to 120°C and excellent UV stability.

KNX - ‘The Green Home Automation Solution'

One popular system for intelligent building design is KNX.

KNX is an ideal solution for consultants, specifiers, designers, installers and end users as a flexible, user friendly and energy efficient system.

The KNX standard is an internationally recognised system for home automation and building control combining ISO/IEC (14543), CENELEC (EN50090) and CEN (13321). It also combines and replaces previous Bus systems - EIB, EHSA and BatiBus.

The harmonisation of these standards and systems offers designers, installers and end users a flexible, versatile and ‘problem-free' solution combining certified devices across a range of approved manufacturers - ensuring conformity, interoperability and quality.

All KNX certified equipment has been tested and certified to meet this high standard and only equipment meeting this can carry the logo. This ensures the quality, reliability and guaranteed compatibility of all KNX devices and equipment.

Substantial energy savings can be achieved through efficient building technologies.

Using a KNX shading control system for example can achieve energy savings of 40%. A KNX individual room control can offer savings of up to 50% and a KNX lighting or ventilation control system can provide as much as 60% savings over traditional building management systems.

KNX also offers advances in home or building security. For example, motion detectors, alarm systems and shutter control can all be automated and controlled through the same Bus network.

Notwithstanding the complex technologies it controls, a KNX cabling system is actually remarkably simple with devices and systems interconnected using a single twisted pair cable. This simplicity is one of the many benefits to designers, installers and end users.

FS Cables as member of the KNX association now offers a KNX certified cable.

This features two twisted solid conductor pairs with a foil screen in a green jacket. It has been tested and certified as being suitable for use in KNX systems and bears the KNX logo.

KNX is particularly attractive to consultants and specifiers at the design stage where the flexibility of an entirely open solution allows for the creation of simple installations right up to complex building management functions.

Installations are made easier through clear and simple wiring and with a KNX certified cable installers can be confident of a hassle free installation.

While the KNX system is responsible for monitoring and controlling the data and communication aspect of the network, we have seen an increase in demand for Niltox low smoke halogen free signal and control cables - in particular LF-319. Niltox LF-319 covers a range of conductor sizes and is available either number or colour coded, from 2 to 25 cores.

Applications in IBTs tend to centre around providing power and control to automatic heating and ventilation control systems. The low smoke halogen free properties of these cables make them ideal for installations where the safety of people or sensitive electronic property could be compromised in the event of fire.

Residential Applications

On a more mundane but just as crucial level the universal HIP (Home Information Pack) with its green energy efficiency rating for homes on sale has familiarised vendors and buyers in the home market to the need for energy conservation and efficiency.

Intelligent building automation has a significant role to play in energy conservation.

Owner occupiers are now required to provide a ‘green passport' in the shape of the Energy Performance Certificate which measures both the current and potential energy efficiency ratings of a home.

Commercial Applications

Just as the home owner needs the HIP to demonstrate environmental performance - there is increasing pressure on businesses to prove their own green credentials. Intelligent Building Technologies can provide benefits to businesses through reduced costs, increased efficiencies and higher employee productivity.

Commercial premises have much to gain with significant ROIs being available through intelligent building automation.

At FSC, we have recently been awarded ISO14001 accreditation which required a critical evaluation of our environmental capabilities.

As a result of this evaluation we identified the need to replace the sodium low bay lighting in the warehouse with movement detecting T5 fluorescent lamps. This ensures that energy is used efficiently and only when required. ISO14001, through systems like this enabled us to significantly reduce our carbon footprint.

Benefits to the end-user

For the end user, a KNX system represents a modern, cost effective and ‘barrier free' solution to home automation and building technology.

Tremendous flexibility is offered as any changes or upgrades to the system over time are possible without the need for rewiring.

Benefits to the Electrical Contractor

The implications of building automation systems for installers are far-reaching and provide a new commercial horizon for the enterprising installer. New build projects and retro-fit schemes offer exciting possibilities in both residential and commercial applications and are an effective way of adding extra value to a job.

In many cases, the hardware and labour costs are outweighed by the value-added benefits for the client.

Using a KNX system has multiple benefits to the electrical contractor. Firstly - the interoperability of devices across a range of manufacturers and regions and secondly - quality assurance whereby product quality is ensured through testing and certification.

Conclusion

While the future for intelligent building automation seems clear the jury is still out on whether Capello will take Neville to South Africa this summer.

If he stays at home, Neville will be able to entertain himself with some high-end gadgetry for his new home. If he goes, he will be able to control his home from his hotel room in Rustenburg, perhaps recording the England games - and hopefully one of those trademark crosses for Rooney to score.

 

Useful links

http://www.knx.org/

http://www.niltoxcable.co.uk/

http://www.fscables.com/

David Hatherill, engineering manager for Finning Power Systems, outlines the process of  generator synchronisation to the mains

If you've watched enough films you will have inevitably seen a few chase sequences and stunts where someone jumps from one moving vehicle to another.

In many ways this is similar to the process of generator synchronisation. Fortunately though we have the assistance of accurate instrumentation and control equipment, which means that the process is rather less risky, and in the majority of cases fully automatic.

We can't however see whether two electrical circuits are in phase or at the same frequency so it's always been necessary to have some form of visual aid. Initially these took the form of two (or in some cases three) synchronising lights - the set being in phase and at the correct voltage when both lights were extinguished.

More recently electronic synchroscopes have been used which give a much better visual interpretation of what is going on. These evolved into having a combined check sync relay, and finally into the modern auto synchroniser used today, which has some limited indication, but has no opportunity for manual intervention.

The fact the process has been automated to the point of the system ‘pressing the button' for you, doesn't mean that the fundamentals of what it's doing doesn't matter anymore. The design of much of the rest of the system is much the same, so we'll now look at some of the other design aspects of synchronising and connecting to the grid.

To synchronise successfully we first need some form of common reference point, and generally this is the neutral on an LV system, which is why we normally want a three pole synchronising circuit breaker. We then need to match the voltage to the supply by adjusting the regulator settings, and make sure the frequency is the same and in phase which we do by adjusting the generator speed. Assuming that these are all correct we can close the synchronising breaker. Once the synchronising breaker is closed we must then increase the engine fuelling to export electricity.

One of the first parts of designing any system is to determine the functionality we desire, and in this case that is whether we want to synchronise generators to each other, to the grid, or both.

If we want to connect in parallel to the grid, then the local REC should be an early port of call to check that they will be happy to connect you. This is important as they may have limitations caused by infrastructure which will limit how much can be connected or impose other design limits. A good example of this may be fault level, which even if you do not export, still has an impact on their network if parallel running is required.

A document called Engineering Recommendation G59/1 covers the requirements for connection and specifies what protection devices should be fitted to enable parallel running. For larger installations, above 5MW, you need to apply the requirements from document G75/1.

For a generator that synchronises at low voltage (LV) these protections will include: under and over voltage, under and over frequency and loss of mains. The latter incorporates rate of change of frequency (ROCOF) and vector shift of the voltage vector.

If the connection is to be at high voltage (HV) further protections are required. These may include: neutral voltage displacement, earth fault, over current, and reverse power, although these are not ‘prescribed' and are to some extent down to the discretion of the local REC's engineer.

Strictly speaking G59/1 applies according to the connection voltage to the grid of the site, but the spirit of the regulation and the general implementation is it is the synchronisation voltage that is considered.

A further document; (Engineering Technical Report) ETR 113 was issued to ‘clarify" some of the requirements of G59/1, but it should be noted some of these clarifications actually impose additional requirements. Also it does not take into account the strength or otherwise of the local network, so the document is not a clarification in the usual sense.

In the longer term there is intent to combine G59/1 and G75/1, which will make ETR 113 redundant, but this hasn't reached fruition at the present time.

In many ways paralleling to the grid is the easy option because the grid does not interact: you simply have to fit in with what it's doing. The synchronised generator also cannot see load, even on its own part of the system, so can run in a very controlled situation with no transients.

The fact the generator can't see load in this situation probably requires a little more explanation as it's a concept that's not at first obvious. Quite simply, the generator set load is controlled by the engine governor; the governor looks at throttle input and compares this to the desired setting. If the engine speed slows it increases fuelling, and if the engine speed rises it decreases the fuelling. When the generator set is running paralleled to the grid the speed does not vary as the frequency does not vary, so the governor does not sense the load. Further to this, since the generator can't see load, it also can't see other generators, so no particular instrumentation is required to coordinate the activities of other units, even if they are on the same leg of the network.

There is also a common misconception load can be controlled when running in parallel by changing the excitation of the generator, and that if the generator output voltage is raised the generator will carry more load. This is not so.

If the generator voltage is increased beyond the bus voltage this causes the voltage vector to shift which alters the power factor, and all this achieves is to make the power factor worse. In fact tight control of excitation is how generators control their own power factor. They cannot correct load power factor.

When running in island mode with multiple generators the scenario is much more complicated. Firstly generators do see load, and they also see each other, so some form of load share governing system is required. This essentially allows the sets to communicate so that as load is applied or removed from the system they all react together in a coordinated way.

This is particularly important if dissimilar generators are connected together. The reason the generators see load in this situation, and each other, is as load is applied to the system there is no infinite bus to buffer these changes. As such the load on, and therefore the speed of, the generator increases or decreases, and this is reacted to by the engine governor.

All of the above are the very bare essentials of what you need to connect a generator to the grid. Today's customers expect so much more than just a generator which can be started and synchronised to the grid. Modern schemes such as hospitals, banks, data centres, sports stadiums, air traffic control centres and supermarket warehouses all require systems that can not only start and pick up load, but also reconfigure the site distribution system, carry out building management activities, switch high voltage switchgear and the list goes on.

When it comes to generator synchronisation it is best to approach a supplier that has the relevant experience and can demonstrate packaged solutions that are reliable and easy to use.  After all it is a legal requirement to show compliance with the regulations when synchronising generator sets to the mains, and there are always the financial benefits of peak shaving. It is likely such benefits will only increase in the future with the continued strain placed on the utility grid.