Power testing critical in keeping data centres running

Paul Boughton

Paul Brickman discusses the reasons behind this rapid growth in the data centre market and how this is a reflection of the critical need for more robust testing

One of Crestchic's first ever loadbank customers was in fact an early data centre at the Littlewoods stores head office in Liverpool, UK, more than 30 years ago. Since then our presence in this sector has grown significantly. We have seen sales increase from six to seven units per annum to around 65 units per annum. Today, data centres account for 30 per cent of our business. So what is driving this growth?

On a power trip

In 2013 it was widely reported that 90 per cent of the world’s data had been generated in the two years prior, leading to the coinage of the term ‘Big Data’. This gives some context to the scale of the data centre industry and the increased risk that surrounds it.

Furthermore the amount of power that data centres use is growing by the day, with the most recent report stating they use 3% of the world’s electricity, while IT as a whole is accountable for at least 10%.

According to a survey by 451 Research states that there will be an increase in data centre facility spending which will originate from both medium and large organisations in Europe and North America, with the healthcare and finance industries leading the pack. This indicates continuous modifications and improvements to the equipment hosting the data, which in turn will need qualifying and robust testing with equipment like loadbanks.

The intensification of risk

The uses for data have also evolved at a rapid pace. We now have data for banking, online groceries and mobile phones meaning that increased risk is acting as a driver for rigorous power testing. Essentially modern life is reliant on the continued performance of a data centre.

Additional security concerns are also fuelling the predicted spending in 2015, mainly due to the constant news reports about data breaches. For example the recent Carphone Warehouse controversy where personal details of up to 2.4 million customers may have been accessed in a cyber-attack.

Evolving buying patterns and specification

While the data market expands, the design of the centres themselves has become more sophisticated. Downtime is not an option in this market, which is why these powerful systems are required to run continuously for the duration of their existence, hence reliability is crucial. In order to ensure this, the infrastructure needs to be systematically tested on a regular basis. This means that the electricity powering the equipment needs to be replicated as realistically as possible. This is where loadbanks play a vital role.

Traditionally data centre loadbanks have been associated with the healthcare and finance industries, however we have found that the sector has now overcome these expectations. Rather than specifying as a retrospective piece of equipment, as in the early days, companies are now realising that they have installed all of the necessary power and that it is too important not to test. Therefore loadbanks are now more frequently being specified at the front end of data centre design alongside architects and consultants. We have worked with many consultants to ensure they meet initial and future design developments. With city centre living on the increase we are also finding that there is an increased need for reduced sound pressure levels.

Power factor

There are various options with regards to power testing – resistive and reactive. The most common form is to use a resistive loadbank to run the prime mover, connected at the generator’s bus. However, this fails to replicate the actual stresses produced during real-world generator operation. A resistive-reactive load test of an installation’s power system can accurately simulate the system’s response to a changing load pattern, such as would be encountered during a real power failure.

However, as resistive loads are usually only a small part of any data centre’s total power consumption the influence of a lagging power factor (pf) <0.8 due to reactive loads is underestimated or even ignored. Generally the only equipment operating on a resistive-only load are incandescent lights and electric heaters; these units draw a steady supply of electricity from a generator, but do not produce the large block loads that truly test a generator’s performance.

A resistive load test will verify that a generator’s prime mover is working, but it will not identify how well it will actually perform when exposed to the real reactive load pattern. Resistive/reactive testing can also reveal additional stresses (and predict pending failures) of a system’s switchgear, alternators, and other systems that resistive-only testing cannot.

Not just power security

In addition to the commissioning of emergency power systems, loadbanks have a crucial role in air conditioning testing. Air conditioning plays a vital part in keeping server halls at stable temperatures and humidity levels and more often than not is designed with extremely high levels of capacity, redundancy and future expansion in mind. With millions invested in the most advanced technology, the air conditioning plant must be commissioned against stable and traceable heat loads.

Resistive only loadbanks can provide a portable and highly controllable heat source to allow air conditioning systems to be thoroughly commissioned against their design criteria. The loadbanks are small enough to be placed directly inside the server halls and can be controlled independently at 1kW increments, or operated as multiple units at the same or differing kW heat load increase and/or decreases. The distributed heat can then be measured by various temperature sensor and probes, or by thermal mapping devices, to ensure the air flow and cooling is evenly distributed and that there are no ‘hot-spots’ around any vital equipment enclosures.

The future…

In such a rapidly expanding market, it is difficult to forecast what could be around the corner. However, at Crestchic we are seeing more developments overseas in this market, such as the recent appointment of a new partner in Poland, BCA Group. Furthermore, in response to the express requests of data centre customers, we will also be launching a leading power factor capacitive loadbank to address the issues discussed above.

Paul Brickman, Sales and Marketing Director at Crestchic.