Power supply: it’s a matter of quality as well as quantity
16 March 2014
For many businesses, the importance of maintaining an emergency power supply to their critical equipment is well understood, with most employing uninterruptible power supply (UPS) technology to do the job. However, what many don’t realise is that the quality and not just the continuity of their power supply also effects how well their critical equipment continues to function. Rob Morris reports.
Poor quality power can damage sensitive electrical equipment, hindering performance and sometimes causing fatal damage. But what is poor quality power and how can businesses protect themselves against it?
Power quality can be broadly defined as any abnormal variation in the voltage magnitude in the mains power supply and can originate from a variety of different sources. External events such as surges, brownouts and lightning strikes can affect the grid, often meaning that the power sent to end-users is of questionable quality.
Poor quality power can also originate internally. For example, overloaded transformers or electric motors being switched on and off can cause pollution or disruption on internal electrical circuits. Until a few years ago, these poor quality power issues did not represent a serious threat to businesses. However, with increasing sophistication, electrical equipment and electronic components are becoming more and more sensitive to poor quality power.
Poor quality electrical power can effect equipment in a number of ways. Damage can sometimes be immediately apparent, like when a surge fries electronic components and the evidence is, literally, left in a puff of smoke. However, more often than not, the damage occurs slowly over time. When the component eventually fails, the cause is not always immediately obvious.
Power disturbances can cause the electronic systems to make the wrong decisions leading to disruption. Low amplitude power disturbances can exceed the low voltage tolerance of a material causing a weakening of the material, and therefore a degradation over time. And when the power disturbance is very large, the destruction of the components will be apparent in the smoke, soot and charred remains left after the event (ususally as the result of a lightning strike or a massive surge from the grid).
There is very little to be done about poor quality power coming from the grid. Similarly, applications that cause electrical interference internally often represent critical equipment that cannot be turned off just because it is causing poor quality power problems.
Protecting critical applications with UPS that contain power conditioning components is the only way of ensuring that poor quality power doesn’t damage and potentially destroy these key pieces of equipment. Power protection devices should ideally always include a low impedance isolation transformer, surge diverters, noise filters, voltage regulators, battery backup systems, and frequency regulators. The low impedance isolation transformer provides protection against spikes and electrical noise, with the other components providing protection against voltage and frequency variation as well as power cuts.
Planmeca: a case study
One company that realised the benefits of power conditioning equipment is Planmeca. In 2008, when Planmeca approached Powervar, they were experiencing a high number of hardware problems. These resulted in a high service burden rate - the proportion of the price of the product which is allocated to cover on-going maintenance and equipment repairs during the warranty period.
It was discovered that most of these problems were caused by high frequency noise on the 120V, 12A power supply, caused by the compressors and vacuum systems used in dental surgeries. This noise caused slow degradation of components, which not only led to failure of components, but also the less reliable operation of digital circuits.
Like many businesses, Planmeca had already integrated UPS systems in its imaging equipment but this had proved insufficient for the environment in which the products were used. However, a trial installation of Powervar power conditioners in two initial sites proved successful.
Planmeca now integrates power conditioning software in all units deployed in North America. The results of this have been clear; the service burden rate was reduced by 70 percent, leading to an impressive RoI of 1,148 percent. In monetary terms, this equates to an RoI of $7,650,000.
When it comes to essential electrical equipment, it is clear that both the quality and quantity of the power supply are important factors to consider. As Planmeca found, there is a clear business benefit to using power conditioning equipment, which not only provides an impressive return on investment, but also improves the customer experience by increasing reliability.
With the changing power environment, it is important that businesses are aware of the damage that poor quality power can inflict. By investing in power conditioning equipment, businesses can protect their critical equipment from the consequences of poor quality come rain, shine or lightning strike.
Rob Morris is UK country manager, Powervar
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