Electrical Review - March 2017

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Informing the electrical industry for over 140 years

March 2017 Volume 250 | No 3 www.electricalreview.co.uk

Technology to market Improved quality of supply to customer

UPSL Green data centres

Surge protection/ lightning protection Powering the future of business




NEWS Beama proposes practical action

ENERGY EFFICIENCY The rise of retrofit

08 GOSSAGE Gossage:gossip

12 COOLING Data centre takes advantage of climate

EDITOR: Elinore Mackay 020 8319 1807 elinorem@electricalreview.co.uk PRODUCTION MANAGER Alex Gold 020 7933 8999 alexg@sjpbusinessmedia.com


SALES MANAGER Sunny Nehru 020 7933 8974 sunnyn@sjpbusinessmedia.com

SURGE PROTECTION /LIGHTNING PROTECTION Powering the future of business

SENIOR SALES EXECUTIVE Jai Rehal 020 7933 8985 jaipalr@@sjpbusinessmedia.com PUBLISHER Wayne Darroch PRINTING BY Buxton Paid subscription enquiries Tel: +44 (0) 1635 879361 electricalreview@circdata.com SJP Business Media PO Box 6009, Thatcham Berkshire, RG19 4QB, UK

18 ENCLOSURES How to design and size a busbar

39 VOLTAGE OPTIMISATION A comparison of technologies

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22 TECHNOLOGY TO MARKET Improved quality of supply to customers

41 PRODUCT WATCH User platform and app for improved 1080p `hdview CCTV range


4 | NEWS

Housing white paper released

Bsria has welcomed the government White Paper on Housing setting out the government’s preferred strategy in tackling the country’s housing crisis. As described in the White Paper, 225,000 to 275,000 (or more) new homes per year will be needed to keep up with population growth and years of under-supply. That could translate into almost one million new homes built by 2020. Among other issues, the White Paper discusses the role of the local authorities in delivering higher housing volumes, potential changes in the way planning permissions are granted, new and innovative accelerated construction processes, the need for supply chain improvements and also addresses quality and sustainability. For private developers, in line with the recently released industrial strategy, Government aims to boost productivity, innovation, sustainability and skills by encouraging modern methods of construction in house building. Government also expects builders and developers to take responsibility for investing in their research and skills base in order to create more sustainable career paths and genuinely bring forward thousands of new skilled roles.

Electrical Safety First’s response to the Department for Communities and local government’s white paper on housing Emma Drackford, of Electrical Safety First, said: “We welcome the government’s commitment to consider mandatory electrical safety checks for rented properties. With a higher proportion of households entering the private rented sector, we strongly argue the need to provide regular electrical safety checks for all tenants throughout England. We know that electrical hazards pose a very real threat to tenants; for example, reports from London Fire Brigade show that electrical fires as a proportion

are increasing in the capital. “We have long called for mandatory electrical safety checks to be conducted within a maximum five year period. This position has been a shared one amongst the stakeholder community, and in line with what has been introduced in Scotland and those now being pursued in Wales. Without regular mandatory checks, we believe that fires caused by electricity in the private rented sector the issue will only get worse, not improve.”

GS Yuasa Lithium-ion cells to be installed on International Space Station GS Yuasa Corporation has announced its lithium-ion space cells have been adopted for use on board the International Space Station. The high-performance lithium–ion cells will be shipped to the ISS from December 2016 and will replace the space station’s current batteries. Developed and manufactured by GS Yuasa Technology Ltd, the space lithium-ion cells boast high energy density and long life. They have optimal design for ISS operations, which require highly efficient charging and discharging. The cells also have high energy density for their mass, which is about three times that of the cells currently installed on board the ISS. This means that just 24 of the new lithium cells will deliver the same performance provided by the 48 nickel-metal hydride batteries currently in use.

The new ISS cells will be delivered into orbit by the Japan Aerospace Exploration Agency in four batches by the H-II Transfer Vehicle KOUNOTORI. GS Yuasa Technology develops, manufactures and distributes cells, batteries and power sources for special applications. It has supplied various high-performance, high-quality batteries for special environments such as deep sea submarines, land based industry and transportation, aviation and space satellites. In fact GS Yuasa batteries are used in locations ranging from depths of 6,500 meters below the ocean surface to 36,000 kilometres high in space. Going forward, the GS Yuasa Group will continue to contribute to space development projects through the development and manufacturing of high performance lithium-ion batteries.

w: www.spec-ltd.com e: enquiries@spec-ltd.com t: 01924 871 558 SPEC Ltd has recently expanded its services to meet the individual needs and demands of the customer to become a national company with regional presence. With a proven track record of successfully working with many service users from small businesses to large Blue chip multinationals both UK and overseas. Established as a total substation service provider, in the role of control, installation, cabling, operation and maintenance of mains 415/11000/33000 & now 66000 and 132,000 v power networks. To date SPEC Ltd operate and maintain over 2,500 HV connected sites nationwide from its 6 strategic regional offices in Washington, Lancaster, Wakefield, Bromsgrove, Oxford and Aldershot.

Electrical Review | March 2017

Head Office Unit 5 Eagle Point, Telford Way, 41 Industrial Estate, Wakefield, WF2 OXW Fax: +44 (0) 1924 871559

6 | NEWS

LIA trainers recognised Former trade minister appointed president of the Institute of Export & International Trade by the Institute of Training and Occupational Learning

The Lighting Industry Association’s (LIA) QA and training development manager, Paul Sargent, and Andy Guest, LIA’s membership services manager have both been recognised as qualified in Certificate Programme & Training Practices by The Institute of Training and Occupational Learning (ITOL). ITOL is the UK’s elite professional body for trainers, learning and development professionals and has become recognised as the premier organisation for everyone involved in the world of training and development. This qualification builds on Sargent and Guest’s vast industry and technical knowledge. Safeguarding their continued professional ‘training experience’ for the Lighting Industry Academy (Academy), but also respond to the changing world of training and development needs within the lighting community. Sargent and Guest present the Academy’s course on BS EN 60598-1 Edition 8. Explaining what the standard requirements are, how to apply them and not forgetting the new LED luminaire requirements. They also take a comprehensive look at the changes from Edition 7 and how these changes will affect luminaire manufacturers.

Electrical Review | March 2017

Lord Green of Hurstpierpoint - a former Minister of State for Trade and Investment – has been appointed as president of The Institute of Export & International Trade (IOE&IT). As trade minister from 2011 to 2013, Lord Green’s remit encompassed promoting UK industry overseas as government spokesman in the Lords for both the former Department for Business, Innovation and Skills and the Foreign and Commonwealth Office. Lord Green was chairman of HSBC Holdings from 2006 until 2010. As the Institute’s new president, he will be instrumental in driving the strategy and vision of the Institute - the UK’s only professional membership body supporting the interests of everyone involved in importing, exporting and international trade. Lord Green said: “The Institute of Export & International Trade is one of the nation’s best kept secrets. Their range of qualifications from 16 through to Masters is professionalising international trade and brings the highest level of expertise and education in skills most needed in the UK today. This knowledge is building business competence and in turn confidence to trade internationally. As we look to new markets across the world I am proud to be a champion of this much needed resource for UK businesses.”

IOE&IT director general, Lesley Batchelor OBE, commented: “Lord Green’s powerful reputation in international commerce is second to none and he joins the board at a formative period for the Institute, whose remit to boost the UK’s exporting drive and economic recovery has taken on an unprecedented importance as we prepare to exit the EU.”

Alastair Ramsay Alastair Ramsay, sustainable development manager at Legrand UK and Ireland, died peacefully on 28 January 2017. Ramsay joined the Legrand team in 2001 as part of the Wiring Devices business, and soon became the company’s representative on many national and international standards committees. His expertise, energy and enthusiasm led him to be a member of many industry committees, including chair of the Construction

Products Association and the Building Regulations Technical Committees, as well as vice-chair of the Lighting Controls Group and Environmental Technical Committee through Beama. With an unbounding vivacity for life and a continuing thirst for knowledge, Alastair was a joy to meet and an honour to know. He will be remembered for his kind and generous nature and for his unrivalled knowledge of our industry.


GOSSAGE A bas la difference

Safety last

Over recent years I have regularly expressed my concerns about the gaming the UK government’s convoluted Contracts for Difference scheme seems to encourage. This is the bidding system that allows electricity generators to offer forward winter capacity to the National Grid. Its original purpose was twofold: to ensure the lights stayed on. And to ensure more eco-friendly sources of power came onto the system, in other words combined cycle gas turbines rather than diesel and coal-fired generation. Despite this, for several years it has been evident quite a number of the auction winners were precisely those ‘dirty’ power suppliers. And that conversely absolutely no new gas fired stations were being built as a result. Clearly though the first objective, ensuring power is available on demand, has occurred. But the significant point is: at what cost has this been achieved? Year on year electricity consumption has been falling. It was 29,981 ktoe in 2005; by 2015 it was down to 26,031 ktoe. That is a 15.2% drop. But of course that electricity is not consumed on a consistent basis. More of it is used late afternoon, in the winter, midweek, than it ever true on an early summer Sunday morning. For the last couple of years there has never been peak demand above 50 gigawatts. Nonetheless last month a power auction took place to guarantee 53.6 gigawatts of winter power. That is an excess reserve of approaching 8%, which in every probability will never be used. But the owners of which generation capacity will be paid, regardless. The end result of this convoluted and opaque system is that overall the cost of running our electricity system next winter will be approaching one-quarter of a billion pounds higher than it needed to be. And we shall all be paying for this luxury.

The UK government’s confirmation that Brexit included leaving the nuclear regulatory body, Euratom, was inevitable. It was all too difficult for us to remain a part of Euratom – and therefore subject to the European Court of Justice plus tariff-free borders for the nuclear industry’s equipment and skilled workers – even whilst pulling out of the European single market, free movement of people and customs union. In common with many of the implications of Brexit, the consequences of pulling out of Euratom are creating great uncertainty. Besides the large question marks facing research programmes like JET and ITER, involving many UK physicists and overseen by Euratom, it is clear that Brexit will both increase the costs of regulating existing nuclear facilities, and increase further delay in the building of new power stations while the United Kingdom makes new regulatory arrangements. One thing is certain. Pulling out of Euratom means that British nuclear power stations, established as well as new, now will not become part of the new European Union nuclear accident liability regime. This will shortly be valued at some 2.5 billion euros per nuclear accident. Given that current UK nuclear accident liability cover is a meagre £164 million, one wonders how much consideration HM Treasury has yet given to ensuring we will be at least as well protected against nuclear accidents as the citizens of Bulgaria or the Czech Republic. Perhaps this is simply another financial liability that will be left to fall upon the relevant local authorities hosting these nuclear stations?

Kettle calling pot black Whenever league tables are published, whether for the most expensive or the most complained about, of the Big Six electricity companies, you can be sure RWE nPower will show up badly. It has so many fewer customers than the others that wags have taken to calling the cartel the Big Five and a Half. Now the company has surpassed its usual measure of incompetence, by announcing price rises of 10%, way above the industry norm. Thus ensuring universal condemnation over every front page, as well as from every political party and the regulator, Ofgem. The main excuse given is never the company’s incompetent forward power buying programme. But, as ever, blame is placed upon the increased costs forced on them by government-imposed programmes. Amongst the main culprits cited is the cost of rolling out 53 million smart meters to addresses occupied by SMEs and households. Conveniently forgotten is the main beneficiaries of this programme are very much not the individual consumer. But rather the Big Six (or even the Big Five and a Half) themselves. Installing these meters allows them to dispense with the cost of employing companies to send out meter readers. It allows them to dispense with most of their banks of telephone answerers, dealing with queries on estimated bills. And allows them to have far greater knowledge of individual customers’ consumption pattern.s By ensuring each company has been installing their own smart meters, it has ensured customers seeking to switch suppliers will forgo manyof the (minimal) benefits a ‘smart’ meter may be bringing to them. It was precisely to acquire these very tangible financial benefits all the suppliers lobbied government hard to create a mandatory scheme to roll-out smart meters. It is a bit rich for any of the Big Six, even a Half member, to be moaning about this as an unwarranted obligation pushing up their prices, forced on them by government.

Scots wha’ hae Got a cold home? Hoping for some help from government to get it insulated? After all, approaching half the homes in the UK are still substantially under-insulated, according to official figures. If so, your chances of getting that insulation installed into your roof, loft or walls are very significantly higher if you live North of the Border. As well as having a far more ambitious climate change reduction programme, as well as all its electricity due to be non-fossil fuel based by 2025, the Scottish government is also now prioritising insulating its buildings. With its new policies, the Scottish government – with just one-twelfth of the population of England – will be delivering over 41% of the insulation measures that are set to be installed in the whole of England. This means that, over the next few years, cold Scottish households are almost six times as likely to benefit from improved insulation as English ones. Not a very united Kingdom, is it? Electrical Review | March 2017




oltage transformers in energy supply networks need regular tests and calibration in order to perform their protection and metering duties correctly. These tests, based on operator directives or national regulations, always required very complex and heavy test equipment in order to be accurate. This made the tests very time- and cost-intensive.

PRECISE MOBILE TESTING With its software-guided measurement VOTANO 100 can test protection and metering voltage transformers in less than 15 minutes. In a single pass, winding resistance, short-circuit impedances, transformation ratio, and the magnetic characteristics curve of inductive and capacitive voltage transformers are determined. During this process, VOTANO 100 assesses voltage transformers with up to five secondary windings – both for no-load and standard load operating conditions. The measured results are automatically assessed in accordance with international standards.

VOTANO 100 AND VBO2: A POWERFUL AND SAFE COMBINATION The VBO1 voltage booster comes with VOTANO 100. This amplifier supplies the primary side of the transformer with a maximum reference voltage of 4 kV for the transformation ratio measurement. The VBO2 is positioned near the test object, while the test engineer operates VOTANO 100 in a secure area outside of the high-voltage environment. The compact dimensions and low weight guarantee easy and convenient transport. The combined total weight of both devices is 15 kg (33 lbs).

ULTIMATE ACCURACY VOTANO 100 examines the voltage transformer as an electrical model that is captured and then mathematically simulated.

Electrical Review | March 2017

This electrical modelling method was developed on the basis of OMICRON’s successful CT Analyzer. The measurement method offers an impressive degree of accuracy. VOTANO 100 achieves measurement tolerances of 0.02% to 0.05%. This allows voltage transformers with class 0.1 accuracy to be precisely calibrated on site with regard to their transformation ratio and phase error. OMICRON is an international company serving the electrical power industry with innovative testing and diagnostic solutions. The application of OMICRON products allows users to assess the condition of the primary and secondary equipment on their systems with complete confidence. Services offered in the area of consulting, commissioning, testing, diagnosis and training make the product range complete. Customers in more than 140 countries rely on the company’s ability to supply leading edge technology of excellent quality. Service centres on all continents provide a broad base of knowledge and extraordinary customer support. All of this together with our strong network of sales partners is what has made our company a market leader in the electrical power industry.


Data centre takes advantage of climate Free cooling and an abundance of low-carbon hydro power is making the Arctic a viable site for data centres. Alan Beresford explains how EcoCooling is taking advantage of the climate at the award winning Hydro66 data centre in Boden, Sweden


here has been a surge of investment recently in data centres in the remote north of Sweden, including Hydro66 at Boden and Facebook at Luleå. The obvious reason for this is the cold climate, which supports ‘free’ cooling and so reduces the considerable cost of taking the heat out of modern data centres. This article describes how Hydro66 has implemented a direct fresh-air cooling system, supported by evaporative cooling, to produce one of the most efficient Electrical Review | March 2017

data centres in the world. Other factors in this region can reduce the capital and operating costs of a data centre, and will also be discussed. Hydro66 has recently completed and populated the first phase of a 20MW data centre in Boden, which – together with the towns of Luleå, Älvsbyn and Piteå – has formed the Node Pole Alliance. The aim of this association is to make the most of the vast natural resources of this area to attract data centre investment. The key advantages are low-cost cooling and power, and

practically unlimited renewable generation capacity and grid infrastructure to support large centres. A key objective of Hydro66 was to design the data centre to operate at a power usage effectiveness (PUE) – the ratio of total amount of energy used by a data centre to the energy delivered to computing equipment – of less than 1.05. This could only be achieved using fresh-air cooling supported by the most efficient uninterruptible power supply (UPS) and power distribution.


days – a DX coil is added to maintain compliant conditions. The obvious key advantage of an indirect ventilation system is that any contaminants in the external air are not brought into the data centre. Because indirect cooling systems require large heat exchangers, the equipment is big and can be expensive. Also, in the case of Hydro66, the Boden planning authorities preferred solutions with no external plant. Hydro66 decided to use a direct ventilation system supplemented by evaporative cooling. The equipment is modular and installed internally, thereby avoiding planning issues. Electronically

Boden lies on the 66th latitude and, consequently, is cold, with a record low temperature of -40°C and a maximum of 32°C, although it rarely exceeds 25°C. In this climate, a simple ventilation system can maintain compliant temperatures for much ofthe time, but in the few instances a year when the ambient exceeds 25°C, a supplementary cooling system is required. The options for this are chilled water, direct expansion (DX), and direct or indirect evaporative cooling. A well-designed chilled water system can be very efficient but expensive. It is also only viable for larger cooling loads. The market for a data centre such as Hydro66 is in ‘colocation’, where equipment, space, and bandwidth are available for rental to retail customers. The final cooling loads are not known at the time of construction, so it is impossible to size a chilled water system to reflect an unknown load. IT equipment is normally installed in 600mm-wide racks, and rack loads can vary Electrical Review | March 2017

between 2kW and 15kW, depending on the type of equipment installed. This is why most data centres take the DX route; units of up to 100kW of cooling load can be added in a modular way, reflecting the cooling load as the computer racks are populated. Indirect cooling is the next option;

A well-designed chilled water system can be efficient but expensive outside air passes on one side of a heat exchanger and the hot air from the centre passes on the other side. The amount of heat extracted is dependent on the outside temperature. On warm days, the ambient (outdoor) air is adiabatically cooled using wetted pads or sprays, and – on very hot

commutated (EC) axial fans are used for air movement because they are easier to install and take up less space than centrifugal fans. With very low pressures, axials can also accommodate the larger flow rates and pressure, and their motors are efficient, quiet and have simple speed controls. Hydro66 decided to use a direct ventilation system supplemented by evaporative cooling. The equipment is modular and installed internally, thereby avoiding planning issues. Electronically commutated (EC) axial fans are used for air movement because they are easier to install and take up less space than centrifugal fans. With very low pressures, axials can also accommodate the larger flow rates and pressure, and their motors are efficient, quiet and have simple speed controls. The efficiency of a fan is approximately proportional to the cube of the speed. Data centres require redundancy of N+1, 2N or 2(N+1), so equipment is operated at part capacity. By controlling all of the EC fans as a group – and reducing the air flow rate to that required by the IT equipment – reductions in consumed fan power can be achieved, producing remarkable efficiencies. On average, 1MW of IT equipment will require an airflow of 90m3 /s of air at compliant temperatures. A ventilation system, based on EC axial fans, can support 1MW of cooling for approximately 40kW of fan energy use. This adds 0.04 to the PUE of the data centre. If – as in the case of Hydro66 – this is used in conjunction with a rotary UPS solution (a flywheel driven by an electric motor) where losses are <1%, a PUE of


1.05 is attained. Since the data centre has both redundancy and spare capacity, the ventilation rate is reduced and further savings are made. For example, running a fan at 80% reduces energy use by half and, at 50%, to 12.5%.

The combination of high RH and dust or particulates can be a problem An intelligent control system is used by Hydro66 constantly to optimise the fan energy use to reflect actual cooling requirements in a dynamic environment. On warmer days, the adiabatic cooling is enabled, bringing the supply air down to approach the wet-bulb temperature of

Electrical Review | March 2017

the ambient air. In Boden, this means the supply air will never exceed 22°C, which is compliant with all standards without the need to use additional mechanical refrigeration. The use of adiabatic cooling will increase the moisture content, while reducing dry-bulb temperature, so increasing the relative humidity of the air. With reference to the ASHRAE 2011 Thermal Guidelines, high relative humidity (RH) will normally only cause corrosion with other contaminants in the air. If gases such as sulphur or chlorine are in the ambient air, these, plus high RH, can cause corrosion. Boden has ‘clean’ air because there are no local industries producing contaminants. The combination of high RH and dust or particulates can also create problems, so all incoming and recirculating air is filtered. In relatively clean conditions such as those in Boden, EU4 is a suitable level of filtration. Increasing this can result in significant increases in capital cost, maintenance

requirements and fan energy use. A direct fresh-air system operating in arctic conditions at the coldest time of the year can result in very low RH in the data centre. Low RH, in conjunction with other factors, can cause problems with electrostatic discharge (ESD), which can damage IT equipment. The Hydro66 cooling system incorporates a recirculation loop, where – in low RH conditions – the warm air from the data centre is passed over the adiabatic pads to humidify the air above the ASHRAE 2011 Thermal Guidelines’ allowable level of 20%. This novel solution therefore uses the adiabatic pads for two functions – cooling in hot weather and humidification in cold weather conditions. Hydro66 has constructed a low capital cost, flexible data centre, which has achieved a PUE of less than 1.05. The direct fresh-air cooling system complements the commercial strategy with a modular system that supports this progressive development.


How to design and size a busbar The introduction of the IEC 61439 switchgear and control VWDQGDUGV KDV KDG VLJQLÀFDQW LPSOLFDWLRQV IRU WKH GHVLJQ DQG SHUIRUPDQFH RI WKH FRSSHU EXVEDU V\VWHP


here are a number of key factors relating to the design/layout stage of an assembly: The decision as to where to put the busbar depends on the location of the incoming cables and the position of the incoming protection device. The form rating helps determine the layout of the assembly, the position of devices such as the circuit breaker, terminals and the busbar system, as well as whether the busbar requires a cover. Ultimately, the size of the enclosure will be dependent upon both the form rating and the busbar system fitted.The total load has to be pre-calculated as this impacts on the size of the busbar. Consideration must also be given to the IEC 61439 standards because under certain circumstances it requires a rating of 125% of the full load current. Knowing the current loadings means that

Electrical Review | March 2017

watt loss can be calculated which will in turn have a direct impact on temperature rises within the enclosure. Again, this is a key element of the standard, along with the maximum temperature ratings. Connecting conductors to the busbar can cause problems for contractors as any oversized cables may be too large to terminate on the busbar system. Design engineers need to consider this possibility and compensate with different busbar adaptors or terminals. But, remember that any additional copper connections may invalidate the busbar warranty as they could be considered to be extending its capability beyond the tested system. Under the standard, all copper connections above 1600A have to be tested for impact of heat rise on the air circuit breaker. In

addition, the connections from and to the main busbar system have to be physically tested by the original equipment manufacturer of the switchgear system. Essentially, the panel builder cannot make their own. High-fault currents (short-circuits) can obviously be highly destructive. The initial electro-mechanical force generated in fault conditions can be huge – tens of thousands amps. As a consequence, the busbar system must be robust enough to carry the current until the short-circuit protection device (such as a fuse or MCCB) trips. Instructions around how to install the busbar support are the responsibility of the original manufacturer of the switchgear system and issues such as the spacing of the busbar supports are determined by the manufacturer’s testing. These distances are governed by the fault level and the size of the copper bar. They and their spacing (ie. how far they are apart) have a major bearing on the strength of the system; if the supports are fitted too close to each or too widely distant, then the system’s performance under fault conditions could be badly affected.


Integrating Standby Generator Sets into Data Centres By Robert Breadon


nternet connectivity is growing exponentially and as the “internet of things” extends to more devices, usage is only going to grow faster. Predictions for 2020 are as high as 75 billion connected devices. And as we come to rely more on the internet in our daily lives, our tolerance of data outages is diminishing just as rapidly, with loss of connectivity resulting in damaged customer confidence, injury to brands and loss of customers. There are many causes of data centre outages but loss of power doesn’t need to be one of them and a well-chosen generator set can take this concern away. If you’re thinking of installing a standby generator into a data centre’s power system, there are several key decisions: • Data centre generator set selection • Data centre continuous ratings • Generator set package integration • Generator set control systems • Generator set project delivery

GENERATOR SET SELECTION (Fig 1) The first and most important decision is choosing the right generator set rating to meet demands from the critical UPS / IT and cooling / chiller loads (also called the N demand). If the data centre is likely to expand, it’s important to consider that this demand may change over time. The decision on whether the generator set will supply power at high or low voltage depends on the size and overall scale of the data centre, on the tier distribution topology and on the actual space available to accommodate the generator sets. Typically when the N load requirements are above 4 -5 MW, high voltage is the best option. The critical UPS / IT load can influence generator selection in several ways: • UPS battery recharge which can be 10-20% of UPS rating. This power may need to be covered by the generator. In some cases, an operator may opt not to recharge when running

Generator Set Selection (Fig 1) Generator Set Package Integration (Fig 2)

Generator Set Project Delivery (Fig 4)

Generator Set Control Systems (Fig 3)

Electrical Review | March 2017


the generator set. This will affect the design autonomy when transferred back to the mains and presents a risk which the data centre operator must weigh up. • Modern UPSs present quite low levels of harmonic current distortion (THDi) to the generator set although in situations where the UPSs are in bypass mode, the higher harmonic distorting IT / Server load needs to be supplied by the generator set which may require an oversized alternator to ensure the quality of voltage waveform is not affected. • Most modern IT loads present a leading power factor by nature. This does not create an issue for UPSs in normal mode, but again if the UPS is in bypass mode, the leading power factor load must be supplied by the generator set directly and this may cause voltage instability issues which may require an oversized alternator. It’s important to note that the effect of UPSs in bypass mode will depend on the UPS kVA rating in proportion to the generator / generators rating. A supplier will be able to provide detailed support on this and other aspects of generator set selection.

GENERATOR SET PROJECT DELIVERY (Fig 4) The diagram above illustrates a project life cycle from definition through to project closure and handover. When choosing a generator set brand it’s important to evaluate a supplier in terms of their ability to support in the definition of the project, the development of a project plan, the manufacturing, testing and site installation to the final commissioning. Robert Breadon is an Applications Consultant at FG Wilson.

DATA CENTRE CONTINUOUS RATINGS The running duty of the generator set in a data centre application is very important, especially when we look at the requirements defined by the Uptime Institute. FG Wilson in conjunction with our sister company Perkins have developed a Data Centre continuous rating which delivers unlimited hours of annual operation with no restriction on the average load factor up to 100% constant load. This rating complies fully with Uptime Institute Tier III and IV continuous operation requirements and is currently available from the P400-1 through to our P2500-1 models.

GENERATOR SET PACKAGE INTEGRATION (Fig 2) After determining the rating and number of generator sets required to meet site load demands, the physical integration of the units means consideration of ambient, noise, local planning regulations and fuel autonomy. The outcome of these considerations will influence the generator set package installation in terms of noise attenuators, exhaust silencers, cooling systems, package footprint, height and fuel storage. For example if a very low noise level is required this will greatly increase the size of attenuation, exhaust silencers and the overall package footprint, which of course will increase the package costs. It’s vitally important that the criteria outlined are as accurate as possible at the concept stage of the project. A generator set supplier should be able to provide in-depth support during this development phase.

GENERATOR SET CONTROL SYSTEMS (Fig 3) The term generator set control system covers a wide range of features and functions, many of them vitally important when delivering key control requirements for the generator set. For example, the ability to load sequence enables N+1 or N+2 functionally for redundancy. The extensive communication interfaces can facilitate interfacing with on-site management systems and enable operators to monitor the generator set remotely, improving 24/7 maintenance support. Redundant PLC control systems are essential for delivering a high level of availability when managing the primary power of the data centre, essentially the mains and standby primary incomers and distribution.

FG Wilson Engineering (Dublin) Ltd data centre installation



Improved quality of supply to customers Electricity North West has upgraded its data communications network to an ethernet IP-based solution to help improve the service provided by its electricity distribution network


he modernised, ‘non-operations’ network provides increased reliability and bandwidth helping the company to better monitor and control the supply of electricity to 2.4 million properties in the UK. Critical to the project was the use of Westermo’s Wolverine Ethernet line extenders, which enable the existing ageing copper cabling infrastructure to be used, thereby ensuring the project was economically viable. Electricity North West owns, operates and maintains the electricity distribution network in the north west of the UK, connecting more than five million people in the region to the National Grid. The network covers a diverse range of terrain, from isolated farms in rural areas such as Cumbria, to areas of heavy industry and urban populations including Manchester. Electricity North West is continuously looking to improve the quality of service provided to its customers. Effectively monitoring and controlling the 500 primary substations distributed throughout the region is critical to achieve this. The substations ensure that Electrical Review | March 2017

power can be rerouted should a problem arise, thereby helping to minimise ‘lost minutes’ of supply.

MAXIMISING QUALITY OF SUPPLY “Our main aim is to maximise the quality of supply and minimise lost minutes,” explained Paul GornItall, who is the network and field operations manager at Electricity North West and responsible for telecommunications and telemetry systems. “It is imperative that we demonstrate delivery to the edge of the power network and to do this we must have a suitable communications network that supports these operational deliverables.” The data communications network provides the means of connecting these locations back to a centrally located SCADA system. Remote Terminal Units (RTUs) installed at the primary substations route voltages, current, switch states, temperature of transformers and alarms data from connected sensors and equipment. As part of Electricity North West’s continuous improvement programme, the company was installing new RTUs to replace aging legacy

devices and upgrade the communications network which connects these devices. This would help better support existing operations and enable new services to be offered such as CLASS (Custom Load Active System Services - www.enwl.co.uk/class), which uses voltage control to manage electricity consumption at peak times. The existing data communications network was a very large VF serial-based solution, which offered limited bandwidth - only 1200 baud, no redundancy and insufficient resilience. An upgrade to an Ethernet IP-based solution was required to provide much greater reliability, resilience and bandwidth. It also needed to support the broader range of enhanced functions and services. “Ultimately the greater bandwidth, reliability and resilience provided by the Ethernet IP-based network will help to support Electricity North West’s current operations and provide even greater reliability of power supply to our customers,” explained Paul Gornall. “The upgraded and future-proofed communications network will also enable the company to offer a range of


additional services such as CLASS and smart metering, which will further enhance our ability to serve our customers.”

REUTILISING EXISTING COPPER CABLING FOR AN IP NETWORK The existing communications network was based on copper cabling. It was thought that to support an Ethernet IP-based network, a vast new fibre optic cable infrastructure would be required. With approximately 11,000 km of installed cabling potentially needing to be replaced, the size, complexity, time and cost of the project was extremely prohibitive. It was therefore essential to

Enhanced network security was a critical part of the upgrade project find a solution whereupon the existing cable infrastructure could be used, wherever possible. Westermo Wolverine Ethernet line extenders presented the ideal solution to this challenge, as they allow effective Ethernet networks to be created over distances of up to 15 km (depending on cable characteristics), whilst enabling data rates up to 15.3 Mbit/s. Critically, the SHDSL communications technology the devices are based upon makes it possible to reuse many types of pre-existing copper cables. This meant that Electricity North West could avoid replacing its vast cable infrastructure, but still upgrade the network. “Because we have an ageing copper cable network we wanted to install and maintain network redundancy wherever possible to ensure we have a very resilient and reliable solution,” said Paul Gornall. “The Westermo Wolverine line extenders are helping us to achieve this whilst still using the existing cables. As a result, we have installed the devices throughout the entire network.” Approximately 750 Wolverine line extenders are being used to connect the RTUs at the 500 primary substations back to the SCADA system. Around 250 devices Electrical Review | March 2017

have been installed to date at sites across the region. The Westermo Ethernet line extenders have created a robust network offering greater reliability, security, resilience and bandwidth. “We undertook extensive FAT testing of the Westermo Wolverine and found the performance to be outstanding,” said Paul Gornall. “Having installed over 250 devices, we continue to be extremely pleased with the devices and the performance of the network as a whole.” Using a third-party management tool, Electricity North West is able to continually monitor network performance. When starting the project the aim was to attain 2Mb of bandwidth throughout the network, but using the Westermo devices it has been possible to achieve, on average, between 4 and 6Mb, and up to 12Mb on some sections of the network.

WESTERMO ROBUST DATA COMMUNICATIONS – MADE EASY The upgrade of the network is being performed by Electricity North West’s information technology and telephony networking team. The group found the Westermo devices to be very straightforward to install and configure and extremely user-friendly. The DINrail mounting and 48V power supply requirements, typically found in the existing housing cabinets at the substations, meant that the devices integrated very easily with the existing set-up. The Wolverine’s robust aluminium housing, industrial grade components, wide operating temperature range and EMC, isolation and shock standards approvals meant they were able to cope with the challenging environment of the substations. This included low ambient temperatures and installation in close proximately to 33KV power lines, which creates the possibility of inference and power spikes. The operations network is continually expanding as new assets such as wind farms and solar farms are constructed. It was important that the communications network could support this expansion. The two DSL and four 100baseTX ports provided by the Wolverine has helped to future-proof the network by ensuring that additional equipment can be easily connected to the network when required.

NETWORK SECURITY TO THE VERY EDGE OF THE NETWORK Enhanced network security was a critical part of the network upgrade project. The Wolverine line extenders are powered by Westemo’s WeOS operating system, which enables complex networking functions to be easily configured as well as providing unique IP security functionality. By utilising a firewall on each port, it has been possible to distribute firewalls across the network. The advantage of this solution is that it helps to prevent a denial of service attack that might occur if only a single firewall was deployed. Firewalls on each port also helps to prevent unauthorised access to the entire network, thereby improving network security. Westermo’s WeConfig software configuration tool is being used to configure and monitor the line extenders remotely, which helps the networking team to save a considerable amount of time. In addition, during the network upgrade, WeConfig has supplemented the network management tool by helping to easily ‘catch’ SNMP traps (significant events or issues) from the thousands of sensors, devices and equipment. The Wolverine line extenders and WeConfig tool are also being used to monitor and trend the SNR performance of the cable. Cable degradation, caused by age, erosion and even weather, can lead to reduced performance and eventually to line failure. By trending the performance Electricity North West can make informed business decisions on cable replacement. Electricity North West’s networking team are also using WeConfig to ensure continued network performance. The SHDSL diagnostic function has been used to monitor the effect of adding new equipment and services. This information is extremely valuable, providing insight into what to expect in the future and preventing potential problems. “The relationship with Westermo is also excellent. The company is very easy to work with and extremely responsive to our project requirements,” said Paul Gornall. “Most importantly their products are very robust, which is exactly what is required to cope with the demands of the harsh environments of primary substation and ensure the network is extremely reliable.”

26 | UPSL

Green data centres 'DWD FHQWUH RSHUDWRUV PXVW FRQWLQXRXVO\ VHHN WR LPSURYH HOHFWULFDO HIÀFLHQF\ WR FRXQWHUDFW rising energy costs and to provide a green environment, which complies with relevant legislation. Reviewing a facility’s UPS system often suggests valuable contributions to this drive. In this article, Alan Luscombe, director at Uninterruptible Power Supplies, a Kohler company, explains the opportunities for energy savings that can exist within a UPS installation.


ata centre operators are under steady pressure to run a facility with visibly green attributes. Not only does this become increasingly important as electricity prices inexorably rise, but it also improves a data centre’s carbon footprint, in line with corporate responsibility endeavours. This contributes to an amenable working environment and enhanced relationships with local communities, whilst meeting legislative pressures and incentives to create and maintain ecologically responsible businesses. Many large undertakings, for example, qualify for participation in the Energy Savings Opportunities Scheme (ESOS), an energy assessment and saving scheme run by the Environment Agency. Organisations that meet these definitions must carry out an ESOS assessment covering all their energy use, unless they have an up to date, comprehensive ISO 50001 energy management system that’s certified by an accredited certification body. ESOS compliant energy audits must identify energy saving opportunities, although these should be reasonably practical and cost-effective to implement. Participants will probably wish to implement any such opportunities, provided the money saved by reduced energy use exceeds the cost of implementation. However, there is no regulatory requirement to do so. Any participant comprising or including a data centre will almost inevitably contain

Electrical Review | March 2017

a power protection system complete with an uninterruptible power supply (UPS). This can offer opportunities for energy savings depending on the type of UPS installed, and how it is being used. Ideally the onsite installation comprises a modern modular design which can deliver great power efficiency, as well as other benefits, including high availability and scalability. However, in reality many sites have older legacy systems – and these are where the energy reduction opportunities can mainly be found.

TRANSFORMERLESS TECHNOLOGY VS LEGACY INSTALLATIONS Energy savings arise firstly from a move to modern, transformerless technology made possible by advances in power semiconductor technology and the advent of Insulated Gate Bipolar Transistor (IGBT) devices. The technology is more efficient than the earlier, transformer-based designs, with an overall improvement in efficiency across the load spectrum of around 5%. This yields substantial reductions in heat losses and energy running costs. Transformerless systems also bring the input power factor closer to unity, with less load dependence. Input current magnitude is decreased, with associated reductions in switchgear and cable sizing. In some cases, electricity running costs are also reduced. Legacy systems are often operated below their optimum efficiency, because they are

not easily scalable. This lack of scalability means that until recently many systems were significantly oversized, to allow for the prevailing load and any expected future growth. The graph in Fig. 1 demonstrates this by showing an expected load profile that starts at 35% of the data centre capacity, with a projected growth to 90% of capacity over 10 years. The same graph also reveals that a UPS sized for 100% data centre capacity was installed, yet in reality the load only ever reached 35%; accordingly, the UPS remained significantly underloaded, seriously impacting its efficiency over its lifespan. A legacy UPS has a maximum efficiency of about 93% when fully-loaded, dropping to about 90% at 50% loading, and even less at the levels shown in the graph. By contrast, the graph in Fig. 2 shows how a modern, modular transformerless UPS can be applied to the same load and expected growth rate. The UPS capacity originally provided needs only to exceed the actual load slightly, because it can be increased so easily, and incrementally, as and when the load grows. UPS Ltd’s PowerWAVE 9500DPA, for example, can start as a single cabinet with one 100 kW module, often with one more for redundancy. As the load grows, the UPS can be vertically scaled in 100 kW increments by populating the cabinet up to its full 500 kW capacity. Horizontal scaling is also possible, by paralleling up to six frames for a total 3 MW

UPSL | 27

capacity. The ability to continuously ‘right-size’ the UPS capacity to the load allows users to minimise their power and cooling requirement, reducing power usage over the life of the UPS. The modular topology benefits from the improved efficiency of transformerless technology compared with legacy transformerbased systems. Modular UPS systems like the PowerWAVE 9500DPA, and as shown in Figure 2’s example, have a high, flat efficiency/ load curve, reaching 96.1% maximum at 50% load and dropping to 95.8% at 25% load. The overall energy savings, over several years, from migrating to a modular UPS system from a poorly-utilised legacy installation can be quite considerable, as Table 1 shows. Note also that the load/efficiency curves for modern, modular systems are designed to accommodate redundant configurations. These curves are not entirely flat, but instead produce slightly higher efficiency at partial loads. This is because UPS manufacturers recognise that modular systems are typically operated in redundant mode, so no single module will be fully loaded. For example, in an N+1 system comprising two modules in parallel and sharing the load equally, neither will ever have more than 50% loading. Accordingly, the manufacturers have shifted the maximum efficiency performance to the actual point of use. This is reflected in the curve for the 9500 DPA UPS, which, as in the example above, peaks at 96.1% efficiency at 50% load.

Fig.1: Capacity waste due to oversizing in a legacy UPS system

ECO-MODE Boosting UPS efficiency to 99% by operating it in eco-mode is also possible. However, this mode carries risk as well as improved efficiency, so it should only be used after careful consideration of the critical load and site conditions. In eco-mode, power flows directly from the raw mains to the load, bypassing the protection and filtering provided by the UPS rectifier and inverter components. Additionally, the UPS must recognise any mains problem or failure, and switch the load to inverter to assure ongoing, clean power from the battery. Therefore, eco-mode is a viable option only if two conditions are met: • The load is resilient to any disturbance that could reasonably be expected from the incoming mains • The load can ride through the time taken for the UPS to detect a problem and transfer to inverter accordingly. • Ultimately, the question is about whether the 2 or 3% improvement in efficiency is worth the increased risk to the critical load.

Fig.2: Capacity waste due to oversizing in a modern modular UPS system

CONCLUSION Data centre operators, which are under pressure to improve energy efficiency, may benefit from reviewing their UPS installations. It could offer opportunities for energy saving, especially if systems are based on older technologies. Additionally, the flat efficiency/load curves offered by modern UPS systems mean that they can be deployed in redundancy mode for greater resilience, while possibly improving rather than sacrificing efficiency. UPS systems can be run in eco-mode to further improve efficiency, but the decision to use this option depends very much on the nature of the load supported by the UPS. As provided within the Environment Agency’s document ‘Complying with the Energy Savings Opportunities Scheme’.

Table 1: Comparative legacy vs modular running costs for a parallel redundant UPS system supporting a 120 kVA load





s the popularity and demand for LED continues to steam ahead in the non-domestic sector, speciďŹ ers, contractors and installers will be closely evaluating their ongoing maintenance and re-lamping programmes. Without doubt there are considerable savings to be made in replacing HID with LED. Labour savings are key, bearing in mind each HID lamp may require ÂŁ200 - ÂŁ250 in manpower to replace over the life of the equivalent LED lamp. This is based on HID lamps having a typical life of only two years with less than 50% of light output. By comparison quality LED lamps are rated for 50,000 hours and at that time retain at least 70% of their original light output. Then, of course, there are the straight savings of up to 70% in energy costs, plus knock-on savings on buildings HVAC systems due to the higher efďŹ cacy and lower heat output of LEDs compared to HID lamps that actually generate substantial amounts of heat as well as light. For example, one extra kilowatt of heat in the room will need roughly 350 watts of extra AC to move that heat to the outside of the building. The use of sensors and controls will allow even further reductions in energy consumption, sometimes by as much as an extra 50 percent saving depending on the application. As user appetite for LED grows, re-lamping strategies must prove equally cost-effective and convenient. They will also need to be future-proofed as over time even the most reliable LED technology will require updating, despite a 50,000 hours lifetime allowing in some cases 8-12 years between re-lamping. While the cost of LEDs and ďŹ ttings is gradually falling as market demand grows, it can sometimes still be cost prohibitive for many buildings premises and estates in the public and private sectors to make wholesale switches to LED ďŹ ttings. Furthermore, installing complete LED ďŹ ttings means there is limited possibility of simple future upgrades, and that’s where the LED HID retroďŹ t lamp comes in. After the initial payback period (normally between 12 to 15 months) the LED retroďŹ t lamps can easily and economically be replaced with a more efďŹ cient version of the same lamp. For example there are lamps that were 150w producing 12,000 lumens 18 months ago, and now that same lamp runs at 140w and offers 16,000 lumens thanks to the improvements in LED efďŹ cacy. We discussed in Electrical Review in September 2013 an alternative to undertaking complete LED HID system upgrades. At that time we suggested the emerging retroďŹ t approach could offer a more straightforward and lower cost upgrade path by simply allowing the replacement of HID lamps with the latest high quality LED solutions, whilst still retaining the existing light ďŹ ttings. In addition, LED retroďŹ t would allow continuous upgrades as LED technology performance improved over time. That has Electrical Review | Maech 2017

now happened and there are now retroďŹ t lamp designs that can be used in almost any lighting application. Looking back, however, a lack of sufďŹ ciently high quality products, and the unfortunate ooding of the market with low quality imports, have perhaps prevented a more rapid acceptance of retroďŹ t LED in the UK market. The former has much to do with UK market education and awareness as in reality there has been availability of quality retroďŹ t solutions for some time. Today, one or two manufacturers now address most typical HID re-lamping applications. Light EfďŹ cient Design, for example, offers a broad product range, fully CE/ROHS tested, to ďŹ t the most common types of ďŹ ttings when replacing 50 – 1000w discharge lamps. The company has also recently introduced the ďŹ rst range of 35 and 55w SOX bayonet cap retroďŹ ts for replacing these increasingly hard to ďŹ nd and expensive lamps. Products are generally supported by a ďŹ ve year lifetime warranty coupled with a two year on-site warranty, a UKbased national sales and technical support subsidiary, and regional warehouse network.

BUYER BEWARE As far as low cost imports are concerned, tougher EU legislation and certiďŹ cations are slowly squeezing out these imposters. For too long they have served to create market uncertainty and doubt when it comes to the reliability, light quality and overall suitability of retroďŹ t for serious commercial and industrial LED applications. It is therefore worthwhile outlining a few of the major factors which may help in the differentiation of the good, the bad and the ugly!

LUMEN OUTPUT One such example is the misinformation delivered by some providers over lumen output and CRI. There have been many spurious claims from importers over the lumen output and lifetime of their products, which have neither been ofďŹ cially tested nor certiďŹ ed. It is vitally important that data is based on external testing by accredited laboratories, carried out in accordance with the LM79 and LM80 standards.

THERMAL MANAGEMENT Then there is the correct thermal management of the LEDs and drivers which are absolutely essential to reach the 50,000 hour promised lifetime. LEDs and drivers running at above their maximum design temperature will not last long at all. All Light EfďŹ cient Design Ltd retroďŹ t lamps are designed and tested to work in enclosed ďŹ ttings. Very few other companies can boast such quality or testing. Light EfďŹ cient Design uses long life LED cooling fans in their retroďŹ t lamps. The lifetime of these fans,


specially developed for cooling LEDs, is 70,000 hours, which is way in excess of the expected LED life of 50,000 hours. Therefore, always check that any lamps are fully tested and that the warranty (typically 5 years) is valid when the fittings are used in enclosed fittings. It really is ‘buyer beware’.

walkways. And, as LED technology advances users can take full advantage without replacing the whole system. With the continuing advancements in retrofit technology and by taking into account the pitfalls of specifying low quality products, professionals can now have total confidence in pursuing a retrofit LED re-lamping strategy.

INSTALLATION AND BALLAST A further performance problem experienced by users of retrofit LED has occurred in installations where the ballast has not been bypassed. While there are products on the market which negate this, it is recommended to always bypass or remove the ballast, as using control gear adds wasted wattage. Old control gear can always fail and it is almost impossible to know how long the control gear has been in operation, so it must be viewed as unreliable. Therefore, having assessed the wattage of the lamp to be replaced and selecting the appropriate LED lamp, remove the existing lamp, bypass the ballast and then connect the new LED retrofit lamp. The installation process should take about the same time as a typical HID re-lamping.

Check list: Look for established manufacturers who are able to offer a full line of, fully CE/ROHS tested LED HID retrofits with guaranteed lifetimes. There are many spurious lumen claims made by cheaper alternatives that offer only two or three year warranties Consider the intended application and environmental factors – there may be potential thermal management considerations Ensure correct installation – always bypass the ballast Specify suppressors to protect against surges and spikes in cases of poor power supply quality

ADVANCES IN MANUFACTURING TECHNIQUES Recent years has also seen one or two quality manufacturers adopting new production techniques to further enhance the performance of their retrofit solutions. The use of a conformal coating, for example, is increasingly found in PCB production where a thin layer of polymer is applied to the surface of the PCB and LEDs to electrically insulate the circuit from environment stresses. Condensation, dust, chemicals and shock can all adversely affect long term reliability and light quality. Furthermore the anticorrosive properties of the polymer will extend circuit life. The growing availability of certified, warranted high quality product is therefore allowing the retrofit approach to become much more viable and for an increasingly diverse range of applications and environments; from low bays and high bays for factory, warehouse, retail mall, hotel and office spaces, to post tops, bollards and wall packs for exterior floodlighting and

Electrical Review | March 2017

Check the colour temperature and CRI of the lamp. High colour temperatures are often offered as that shows higher lumen outputs. But the light will be very blue and way below the 80 CRI that should be seen as a minimum for internal lighting applications. 4000k is probably the maximum with 3000k preferable for some interiors Find out how many lamps have been installed and in what environment. There is definitely strength in numbers!


Powering the future of business One of the biggest talking points of 2016 was around the topic of digital strategy. The development of IT infrastructure in recent years has culminated in businesses being expected to have a comprehensive digital strategy. However, this drives a pressing need for an electrical power supply that is continuous and reliable. Here, Matt Collins, business development manager at power distribution specialist ide Systems, investigates how facilities managers can keep IT systems running


usinesses are constantly barraged with IT buzzwords like big data and cloud computing, concepts that they are told offer a wealth of benefits if adopted. These trends, in addition to a shifting business landscape through globalisation and outsourcing, have made it necessary for facilities managers to invest in the right infrastructure to support digitisation. However, beyond the software and hardware, facilities managers often overlook the power being supplied to IT systems. While it’s important that businesses choose the right IT system, so too is ensuring that these systems continue to operate in the event of a power failure or an emergency. For example, there was an incident in 2015 where one of Google’s data centres experienced a power failure. This down Electrical Review | March 2017

time was a result of transient voltages caused by lightning striking the local power grid in Belgium. Unfortunately, several disks worth of data remained inaccessible after the incident. This highlights the need for two things. The first is that facilities managers should ensure that power equipment is protected against lightning strikes and, secondly, that a building’s power supply is connected to an effective changeover system that can keep systems running in the case of an emergency. If a company the size of Google can fall foul of power failure on such a scale, so too can smaller businesses.

CHANGEOVER POWER So how can facilities managers keep IT systems operational? An important step is to invest in a changeover system that meets


the needs of the application. These are designed to facilitate a power supply shift from mains electricity to a backup generator with minimal disruption to service, so they come with a multitude of configurations available. For example, ide Systems was recently approached by a large London-based business to design a 400A manual changeover panel to ensure reliable power to the building’s IT systems. To maximise its effectiveness, engineers from ide Systems designed the panel with a lightning protection unit and, interestingly, a multifunctional power meter that included text message functionality. A powerful feature for remote monitoring, the text functionality offers an additional level of reliability to the system. The power meter’s text message facility works on the incoming mains supply so that, in the event of a mains failure, facilities managers receive a text instructing them to switch the supply over. This gives peace of mind that important IT systems will not lose power. Innovations such as this can only be designed into electrical equipment if facilities managers give due consideration to emergency systems. While it is easy to think of IT systems as the sole responsibility of IT managers and technicians, facilities managers have a key role in ensuring the ongoing power required to sustain an effective digital business strategy.

Electrical Review | March 2017


Seeing the light Building automation specialist BEG has delivered an integrated lighting control strategy to a major 8. HOHFWULFDO HQJLQHHULQJ FRPSDQ\ LQ 2[IRUGVKLUH DQG KHOSHG LW EHFRPH HQHUJ\ HIÀFLHQW


arke & Taylor, a multi-award winning electrical solutions business, expanded its operations from leased premises in Langford Locks in Kidlington to a new fully-owned facility in Blenheim Office Park in Long Hanborough. The company, which specialises in key construction market sectors including the private sector, the public sector, education and commercial office space, required a lighting control solution at the development which would reduce their operating costs. BEG carried out a lighting site survey before recommending a range of products to meet the different requirements of the individual rooms. The German manufacturer, which celebrated its 40th anniversary last year, provided a number of the master-type BEG Luxomat PD9-M-1C-FC occupancy sensors for the main office. These were ideal as this area was open-plan and this type of sensor is designed for rooms where there is continuous daylight evaluation. The PD9 is also favoured by many clients because of its design and the fact it is a small – the size of a £1 coin - and discreet recessed mounted sensor. In the offices where Darke & Taylor’s designers worked, technically known as computer-aided design (CAD) areas, BEG supplied the BEG Luxomat PD2-M-DALI/DSI-FC sensor. This detector is a master-type recessed DALI dimming sensor designed for daylight control of rooms where there are only minor movements. Luminaires are controlled and adjusted with daylight brightness. Darke & Taylor also had the BEG Luxomat PD3N-1C-FC installed – this is a normal switch-in sensor for fast traffic areas so was ideal for the lobby, stairs and bathroom areas in the new offices. B.E.G. also supplied its IR-RC adapter which means all the sensors could be conveniently controlled by the Darke & Taylor facilities management team via the BEG Smartphone App. Keith Martindale, BEG business development manager, said: “BEG is delighted to have met the lighting control requirements of such a large and respected electrical engineering company as Darke & Taylor. “The company was keen to become greener and much more energy efficient when it moved to its owned facility which would not only improve its carbon footprint but reduce its energy costs.

Electrical Review | March 2017

“At BEG we designed a lighting control strategy which involved using three separate occupancy sensors which were the most suitable and provide the biggest savings for the rooms’ usage.” Simon Newton, Darke & Taylor commercial director, said: “As an ISO14001 company that installs low energy lighting, environmental lighting control, solar photovoltaic and energy monitoring systems on behalf of our clients, it is really important to have followed best practice at our own head office in order to reduce our impact on the environment and reduce operational costs. “An added advantage is that we can now demonstrate the benefits of these technologies to existing and potential customers. The BEG Luxomat lighting sensors are an integral part of the energy efficient approach we took to lighting the new office space, and work excellently in conjunction with the entire range of LED luminaires we installed.” Dan Wootten, Darke & Taylor project and design engineer, said: “I have previously used BEG lighting control products on a number of my projects for clients. When I was given the responsibility for the electrical design and installation at our new office facility, it was an easy decision to involve BEG in ensuring I was able to deliver an energy efficient solution that met the demands of a busy working office space. “I received excellent advice when designing the lighting system and the installation and commissioning of the Luxomat sensors was very straightforward.”

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The simplest VO uses a ďŹ xed step-down transformer, or autotransformer, so that the output follows the grid input in a direct reduction ratio. Dropping from an average of 242V to 220 average demands a reduction ratio of 90.9%. When the input mains drops to 235V, the output will be 213.6V, at 230V input it will be 209V, and so on. This is a relatively low-cost but coarse way of reducing mains voltage, and transformers usually come with a range of tappings for manual setting of the voltage drop. This allows selecting the best ratio at installation, and allows for occasional adjustment should the average grid voltage vary by more than a few volts over time.

The simple tapped auto-transformer in [1] above can be automated with relays, SCRs or IGBT switches, by monitoring the output, and changing the tappings dynamically. This technique, known as “tap-dancingâ€? is still relatively crude, giving rise to undesirable spikes and noise from the switching. The lifetime of the relays and IGBTs is limited because they are working with the full load current, at the grid supplied voltage. SimpliďŹ ed layouts of 2 types are shown in Figs. 1 & 2. Auto-transformer derived systems are costly to implement due to winding complexity, and their bulky size and heavy weight can make it more difďŹ cult to ďŹ nd space for installation. Due to the typical copper losses in transformers, which range from 3%-5%, energy loss by heat dissipation is high, as a 20kVA auto-transformer would generate between 600W–1,000W of waste heat.

Figure 1

2A. SERVO-DRIVEN TAP CHANGING In this, very close tappings of a transformer are accessed by rotary or linear contact “brushes� driven by a servo motor, rather than relay or electronic switching. These large, heavy, expensive, lossy, and very unreliable systems are rarely used nowadays.


Figure 2

A standard transformer with primary and secondary has an additional reverse winding included, which may be used to reduce the voltage on the secondary winding. Although the technique still depends on the use of a bulky transformer with signiďŹ cant losses, any activity to control the output voltage via the third is at lower power, increasing electronic reliability over [2]. Transformer complexity is high, lifting the cost of the winding process. As in [2], there are thermal handling issues due to high insertion loss. The simpliďŹ ed diagrammatic difference between a standard transformer (on the left below), and a typical “improvedâ€? version is in Fig.3.

4. ELECTRONIC PHASE CONTROLLERS Electronic phase cutters control RMS voltage by chopping part of each voltage cycle. They use thyristors or SCRs to chop the sinewave and reduce RMS output voltage. These systems have high electric distortion, especially with non-linear loads, require huge ďŹ lters, and generate many undesired harmonics. In addition they cannot handle surge currents such as motor starting. Increasing zero-crossing time intervals produces lampwww.electricalreview.co.uk


Figure 3

flickering and negatively affects lighting systems. Poor power quality and reliability issues make these systems ineffective for most commercial voltage control applications, hence they are rarely used now.

5. LOW POWER PWM CONTROL In contrast, the activolt design is the only one that that offers true continuous setting and control, independent of any discrete steps. The main differences can be seen in the block schematic below. The load current flows directly to the load via the secondary of the small low-loss toroid. The flux in the toroid core is manipulated via the primary winding by the power control board, which contains a low-voltage PWM (Pulse-Width-Modulator) switching at high frequency. Insertion loss is restricted to the resistive loss in the secondary winding of the toroid, together Figure 4 with the relatively low power consumed by the power control system. The relatively high frequency PWM, operating at low voltage and current, means that harmful spikes and noise are effectively avoided. Harmonics up to 13th (650Hz) are attenuated by some 80%. An innovative, high efficiency, low power filter inductor situated at the PWM output further cleans switch noise and harmonics from the drive current to the primary winding. It is interesting to note variable speed drive controllers also use high frequency PWM to drive certain motors more efficiently. Photovoltaic invertors also use PWM (from 20kHz to 200Khz) to create the AC power which is injected into the grid. This does not mean that activolt can in any way replace a VSD controller (or PV invertor), but it does show the value of using HF PWM in controlling low frequency, high power devices.

BENEFITS OF LOW POWER PWM FOR VO Specific advantages of activolt technology • Lowest possible set voltage (210V) • +/- 1⁄2 volt stabilisation (vs +/- 1.5 volt for next best technology) • Rapid response to overvoltage, overcurrent, and temperature alarms. • Lowest insertion loss • Electronics operating at low power, fully isolated from grid input voltage • Fully protected in case of any failure • Best removal of spikes and harmonics (by 80% up to 650Hz) • No mechanical moving parts • Full TCP/IP connectivity • Remote monitoring and control • Small toroid, smallest overall footprint • Best life-time enhancement of equipment

A good VO is characterised in the following ways: • Wide voltage reduction range • High resolution (minimal reduction steps) • Stability of output (allows greater reduction) Electrical Review | March 2017

• Tightness of tracking (also permits operating at lowest practical voltage) • Reduction of surges, spikes, and harmonics • Low insertion loss • Power Factor improvement • Reduce site visits and maintenance costs1 • Improvement in phase balancing2

NOTE 1 Optimising voltage also substantially lessens equipment maintenance costs. The service life of electrical equipment is roughly halved with each 10oC increase in operating temperature. Each one volt increase in voltage raises the operating temperature of most appliances by approximately 0.5oC.

NOTE 2 Each 1% of voltage imbalance increases three-phase motor winding temperature by 10oC. According to the US Department of Energy, the utility standard 3-phase voltage delivery is no more than 3% imbalance. Consequently, voltage imbalance can dramatically lessen both motor efficiency and life even within the acceptable delivery standard. Voltage imbalances greater than 1% have a detrimental effect, a fact of which most consumers are unaware.

PRODUCTS | 41 AUTOMATION INTERCONNECTS Bulgin has launched a new range of industrial automation components which have been designed to offer flexible connectivity solutions for a variety of rugged automation applications. The M-Series interconnects includes a range of sizes and pin configurations – from 3 to 19 pins – and is designed for use in industries requiring exceptionally reliable and robust connections, from automotive production and machine building to food and beverage processing. A variety of connector types and keying options are available, including A-, B- and D-coded configurations. In addition to straight and right-angled field installable versions, Bulgin’s M5, M8 and M12 variants also offer PVC/PUR overmolded cable options to provide end-to-end automation connectivity for almost any situation.

Bulgin • 01223 371 000 www.bulgin.com

USER PLATFORM AND APP FOR IMPROVED 1080P HDVIEW CCTV RANGE Security products supplier, ESP has made further developments to its HDView CCTV range, which sees the resolution increased from 720p HD to 1080p Full HD, to deliver enhanced image quality. These advancements allow ESP to offer a highly affordable and competitive CCTV range that delivers superior image quality. The change in resolution offers improved image clarity and detail due to the additional image processing capability of camera and DVR. The improved quality images is the result of increasing the number of pixels from 1 Megapixel to 2 Megapixels, enabling more data to be captured. This advancement will provide users with better quality live images and recorded footage, which is essential for any CCTV system installation.



Cubic launches a wall-mounted version of the CPS25 panel system – especially designed for switchboard solutions up to 800A. CPS25 is developed with the demands, needs and wishes of the users in mind. The advantages of CPS25 are easy installation, competitive price, and unique flexibility. With the new CPS25 wall model CUBIC now covers 90% of the market for floor and wall-mounted distribution switchboards up to 800A. Freedom, versatility and an almost unlimited number of applications make CPS25 relevant to all industries and situations where switchboards for main and distribution purposes are necessary. CPS25 is independent from component manufacturers, with standard mounting and connections to cover the most common components. CPS25 may easily be designed and assembled in one day.

The space saving combined Type 1 and 2 lightning current and surge arrester from DEHN is now available with volt free remote auxiliary contacts. • High lightning current discharge capacity up to 50 kA (10/350 μs) fulfills the requirements of BSEN62305 for Lightning protection classes III and IV • Fulfils the requirements concerning the lightning current discharge capacity as specified in BS7671 of 12.5kA per pole • Optional volt free remote signalling contact for remote monitoring • Common green/red operating state/fault indication for status indication of all arrester paths • Compact lightning equipotential bonding and protection of terminal devices due to spark gap technology • High follow current extinguishing capability (Ifi = 25 kArms) DEHNshield takes up only 4 standard DIN modules and is ideally suited for installations with restricted space.

Cubic • +45 9882 2400 www.cubic.eu

DEHN UK • 01484 859 111 www.dehn.co.uk

SMART CITY LIGHTING Fulham’s Workhorse Extreme LED drivers are IP65 rated, have integrated surge protection and come in 6 models from 40W to 200W. Each feature variable output current for ultimate flexibility in matching light source characteristics. Depending on the model, the drivers come in either very compact or linear case type. An additional option available to luminaire manufacturers, is integrated wireless management and control with the outdoor LED drivers. Here, Fulham works with Tvilight to provide an integrated driver with wireless, cloud-based, IoT management and controls using the cloud to manage lighting for cities, utilities, airports, railways and other environments. Fulham’s Workhorse Extreme LED drivers integrate with SkyLite, Tvilight’s intelligent wireless lighting control system and also other Zigbee-based systems.

ESP • 01527 515150 Fulham • +31 72 572 3000 www.espuk.com www.fulham.com

MEASUREMENT, RECORDING AND ANALYSIS OF ALL SIGNALS IN PAC SYSTEMS DANEO Control is the PC software for operating DANEO 400, the measurement and analysis system for power utility automation systems. The new version 4.00 of DANEO Control impresses with its new major features and enhancements. Now users can observe instantaneous values live to quickly analyse and verify the wave form, and easily inspect phasors in a phasor diagram and identify predominant harmonics in a spectrum at first sight. Calculations can be created by combining signals with an operator (+, −, ×, ÷, %) and used for recording, triggering, observation and analysing. Furthermore, quality attributes in IEC 61850 GOOSE and Sampled Values can be observed and supervised. This information can be used to trigger recordings on quality changes and get notified via email. DANEO 400 covers a wide range of tasks in different applications, such as fault recording (classical and hybrid), verification of IEC 61850 communication, supervision of network traffic, and the assessment of network performance. The user can keep track of what is going on in the substation by obtaining information on the operational status and communication. Omicron electronics www.omicronenergy.com





Rittal will be exhibiting its global-leading TS IT rack at Data Centre World 2017. The TS IT rack’s reputation has been built around the safe environment it provides for servers and other equipment, its ease of modification, and its outstanding price/ performance ratio. Today’s data centres need both to protect cutting-edge technology, and adapt to the innovation cycles of servers and storage systems. The TS IT has an intelligent modular design offering easy, tool-less adjustments. The standard version includes two fully adjustable 19” mounting levels and a multi-piece roof plate with optimised side-cable entry via brush strips in the roof as well as the option of fan integration. Accessories can also be added or modified without tools. This enables intelligent, versatile expansion and the flexibility of customer-specific configurations. It has been designed with climate control in mind, including IT-specific cooling systems and liquid-based cooling systems such as the liquid cooling systems from Rittal. All this has been confirmed by accredited testing laboratories.

The introduction of the IEC 61439 switchgear and control standards has had significant implications for the design and performance of the copper busbar system. It’s an area which design engineers need to appreciate, not least because the new testing regime and the requirement for compliance has changed the way we think about the selection of the busbar system. There are a number of key factors relating to the design/layout stage of an assembly: The decision as to where to put the busbar depends on the location of the incoming cables and the position of the incoming protection device. The form rating helps determine the layout of the assembly, the position of devices such as the circuit breaker, terminals and the busbar system, as well as whether the busbar requires a cover. Ultimately, the size of the enclosure will be dependent upon both the form rating and the busbar system fitted.

Scolmore continues to expand its successful Inceptor range of integrated lighting products and its latest development brings to market a selection of energy-saving LED Bulkheads that have convenience and speed of installation as their key attributes. The new Inceptor EVO Bulkhead offers a number of features and benefits unmatched by competitor products and Scolmore has patent pending on the product’s design. As well as integrating the control gear and the light source within the diffuser, the bulkhead has the added benefit of a Flow plug which allows for fast and simple connection and disconnection for testing and maintenance of the luminaire. Scolmore believes the Inceptor EVO is the only bulkhead currently available to incorporate a flow connector. Scolmore has taken away the need for time-consuming and unnecessary screws and integrated the control gear and light source within the diffuser and added a flow connector. The installer, therefore, simply removes the diffuser, fits the base to the wall/ ceiling, wires the conductor into the flow connector and secures the diffuser in place.

Ritual • www.rittal.co.uk www.friedhelm-loh-group.com

Rittal • www.rittal.co.uk www.friedhelm-loh-group.com

Scolmore • 01827 63454 www.scolmore.com

SUDLOWS ACQUIRES PROGRESSIVE Technical infrastructure specialist, Sudlows, has completed the acquisition of Progressive Network Solutions, a provider of technical installation services within London, the City, Home Counties, Thames Valley and the Midlands. This strategic acquisition will strengthen Sudlows’ provision of infrastructure services across the southern region. Progressive’s highly experienced management and technical team joins Sudlows in providing enhanced service and increased localised support to both existing and new customers. Based in Watford, Hertfordshire, Progressive Network Solutions is a privately owned independent company. The company was established in 2002 by the current directors Tony Shrier and Tim Sprowson to provide specialist technical services, including; unified communications and critical infrastructures. As part of the integration process, Sudlows and Progressive will be relocating to larger premises. This investment in property and people will form the operational hub of the Southern region for the Sudlows Group.

Sudlows • www.sudlows.com www.progressivenet.co.uk

Electrical Review March 2017

POE FOR REDUCED INSTALLATION COSTS & EASIER CONNECTION Wieland Electric is expanding its range of industrial network solutions with the introduction of the wienet UMS 8-4PoE-W Ethernet switch. The switch has eight Fast Ethernet ports, four of which are PoE capable with an injector function. wienet UMS 8-4PoE-W switches are ideally suited for use with network devices that require little power, for example IP cameras. The joint transfer of energy and data on an Ethernet cable simplifies installation and reduces the cost of the network. wienet UMS 8-4PoE-W is equipped with broadcast-storm and Ethernet ESD, in addition to power line EFT protection, thus preventing network disturbances and outages. Up to 15.4 W power at 48 V DC can be fed per PoE port according to IEEE 802.3af. The switches can be operated in temperatures ranging from -40 °C to 75 °C and boast a robust metal IP30 rated housing that has very good EMC properties.

Wieland Electric • 01483 531213 www.wieland.co.uk

LITHIUM-ION CELLS TO BE INSTALLED ON INTERNATIONAL SPACE STATION GS Yuasa Corporation has announced that its lithium-ion space cells have been adopted for use on board the International Space Station. The high-performance lithium–ion cells will be shipped to the ISS from December 2016 and will replace the space station’s current batteries. Developed and manufactured by GS Yuasa Technology Ltd, the space lithium-ion cells boast high energy density and long life. They have optimal design for ISS operations, which require highly efficient charging and discharging. The cells also have high energy density for their mass, which is about three times that of the cells currently installed on board the ISS. This means that just 24 of the new lithium cells will deliver the same performance provided by the 48 nickel-metal hydride batteries that are currently in use. The new ISS cells will be delivered into orbit by the Japan Aerospace Exploration Agency in four batches by the H-II Transfer Vehicle “KOUNOTORI.”

Yuasa www.yuasa.com


Contact the sales team 0207 933 8974 Lighting