Electrical Earthing Protection
Electrical Earthing Protection for Data centres barely existed thirty years ago. But, in the past few years, they have become essential to the functioning of virtually every large business. And professional organisation.
Very little commercial or administrative activity can take place if the computers are out of action. So, every minute of data centre downtime can have severe consequences for a firm’s profitability. Also, crucially, its reputation. Therefore, sound Electrical Earthing Protection can help to ensure that frequent but unpredictable events. Such as lightning strikes. And power surges do not cause data loss. As well as, severe and lasting damage to sensitive data centre equipment. Therefore, electrical earthing is a matter of vital importance.
Shielded Cable And Earthing – The Faraday Cage
The use of sensitive equipment in data centres is not the only reason for giving special consideration to earthing issues. The shielded cable, which is used in data centres to prevent electromagnetic interference (EMI) in data transmission. Requires earthing to work effectively. The shield works by acting as a Faraday Cage. Thus, preventing EMI from reaching the internal signal wire. However, if it is not correctly earthed. There is a risk of an induced voltage in the shield. Which, can itself produce interference in the signal.
Earth Loops – The Risks
Consideration also needs to be given to earth loops; These occur where two or more earthing connections are at slightly different voltages. Because of the very low impedance in the earthing cables. Even a minimal voltage difference will be sufficient to create a current looping through the equipment. Therefore, back through the earth. This current is detectable as a ‘hum’ in audio equipment. However, have more severe consequences for data transmission.
Electrical Earthing Protection For Data Centre Cabinets
Although many data centres use a conventional electrical earthing system for all their equipment. Therefore, which reduces the risk of earth loops. As a result, there are strong arguments to be made for earthing the data centre racks and cabinets separately. This thinking is to minimise the effects of power surges. A complex issue. Also, getting it right requires careful engineering. It is crucial that the electrical earthing system design aligns with the design of the data centre from the start. Also, all electrical earthing connections are accessible throughout the data centre.
What Electrical Earthing Protection Are Data Centres Required to Have?
British Standard 7671 covers the general requirements for low voltage electrical installations in the UK. However, data centre technology has tended to evolve faster than standards. Therefore, engineers may need to source their information more widely. Using, for example, the American Telecommunications Industry Association (TIA) guide. TIA-942, first published in 2005, which covers data centre standards.
Why Data Centres Electronic Equipment Needs Surge Protection, AND Additional Lightning Protection
Here’s why Data Centres need Surge and Lightning Protection. In recent years, there has been a massive increase in reliance on government and commercial organisations on the use of computer equipment.
Data Centre Surge and the Protection Risks to Electronic Equipment
Whilst bringing huge benefits in improved communication, data storage, and business efficiency. But, this change has also introduced a new area of vulnerability. When the computers stop working, almost every kind of commercial and administrative activity comes to a halt. Also, there are other consequences too for damaged equipment; The cost of repair or replacement will be high. And this cost adds to the financial cost of downtime.
Surge Protection in Data Centre Electronic Equipment
Data centre equipment is complex and sensitive. Much modern electronic equipment includes some form of surge protection as a matter of course; The uninterruptable power supplies (UPS) used, to provide back-up in the event of a brief power failure. For example, often incorporate protection in the form of a metal oxide varistor (MOV). And which uses semi-conductors to transfer excess voltage to ground. So, surge protection of this kind will protect against the power spikes which may occur when other electric equipment. Such as initiating pumps and refrigeration equipment.
Types of Additional Surge Protection
Also, other types of transient voltage surge suppressors (TVSS), which may be installed to protect data centre equipment. And can include devices such as gas discharge tubes and selenium voltage suppressors. Which have relative merits in terms of reliability land longevity. Also, the time it takes to trigger them in the event of a power surge. However, it is vital to note, that all types of surge suppressors work by directing the power surge to ground. So, all require an effective earthing device. Moreover, it is wrong to assume that because some of the equipment in a data centre has its own surge protection. That the data centre itself protected against all risks.
Why Lightning Protection is Different
The electrical surge delivered in a lightning strike involves an extraordinary amount of power. A typical lightning bolt has an electric potential gradient in excess of three million volts per metre. And may deliver many thousands of amps. So, the kind of TVSS system normally installed in a data centre simply cannot guarantee lightning protection. When the surge is of this kind.
Is Real Lightning Protection Possible?
Lightning protection against a direct strike is entirely feasible. But, the important point to recognise is that when lightning strikes. The massive amount of energy it delivers cannot be simply dissipated; It has to be delivered, quickly and safely, to earth. So, whatever devices are used, the earthing system is crucial. For this reason, a data centre’s lightning protection needs to be considered ‘from the ground up’. Also, in which consideration the advice of a specialist will be indispensable.
The Dilemma for New Swedish Data Centre Earthing
With the plan set for 20 new large scale data centres to be built in Sweden by the year 2020. Therefore, the data centres earthing issues could potentially cause disastrous consequences. The Dilemma.
So, it seems that Sweden is aiming to become a global data centre hub. It has excellent facilities, infrastructure and the naturally cool climate means that less financial investment is needed for cooling. So, 20 new large scale data centres in 5 and a half years … that’s roughly 4 a year … and if each facility takes on average a year to build … well, it’s going to be a busy time in Sweden!
In the medium term, employment will rise, especially in the construction industry. Not only that. But there may be technological advancements. Improvements in efficiency and greater overseas investment into the country which would boost the already buoyant economy.
Many plots of land have already been allocated to data centre development and the venture is underway. Although some will argue. That they are eye-sores which are destroying the countryside. The global demand for data centres is growing. And a hub would be beneficial on a world scale. With today’s environmentally conscious approach, I am sure there will be plans to replant trees or protect natural habitats.
Potential Dangers for Data Centre Earthing
If new data centres are located close to existing or other facilities. Technically secure data centre earthing design must be a key consideration.
Generally, Nordic geology is simple – for the most part, it is made of igneous rock such as granite. As a result, the soil structure has a high resistivity. And, which causes it to become a poor conductor of electrical energy. Consequently, in the case of an earth fault; Therefore, the rise of earth potential is likely to be much greater. So, energy from the fault appears to get trapped in the upper layer. As a result, extends out further from the epicentre which can put more lives at risk.
Therefore, if data centres are to be built close together. And a fault occurs on one. Therefore, the returning earth current could flow into the other. Hence, energise buried systems and/or conductive structures such as ‘street furniture’ – e.g. lighting columns, shelters, bollards, or other earth systems.
So, without adequate study and measures in place. Therefore, the very real hazard of electrocution exists. Also, as well as other surrounding systems becoming adversely affected!
Amongst fears of close proximity as well as other factors. Facebook decided against its proposed Osterund data centre site. As seen in the picture. Instead, they built Lulea. – A huge 120MW data centre driven by 100% renewable energy generated from a nearby hydroelectric station.
What Can Be Done – To Avoid Data Centre Earthing Dangers?
So, to ensure ALL that come into contact with the data centre. Staff or otherwise are not at risk. It is critical that the data centre earthing is designed and installed properly. Estimates and uncertainty have no place in Nordic earthing.
Local utilities have begun to realise this issue. Therefore, now recommend that computer software modelling is used to inform firms exactly where the energy from a fault will return. Also, its path, magnitude. And, what elements will become energised along its route. This not only provides companies with money-saving information by ‘right-sizing’ earthing arrangements. And avoiding costly over or under engineering. Also, could save the lives of staff, visitors or the nearby general public.
A Data Centre Earthing Consultant You Can Trust – GreyMatters is 1 of only 4 companies in Europe to be certified. Also, accredited to use industry- standard CDEGS and XGSlab 3D electromagnetic field modelling software. And has over 20 years of industry experience with Data Centre Earthing across the globe. Read a case study on Data Centre Earthing.
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