Electricity is to a data center as blood is to human body – both are lifelines of their respective systems. Electricity is the life force which makes a dead data center and its equipment live and functioning. Hence it is important that this life force is of pure quality if the performance of the components is to be continuous and without any possible chances of damage from the same electricity.
Yet the power quality of the grid power supplied to a data center may not be always as intended. The power could be of poor quality and this could result in damage to the electrical and electronic equipment of the data center. We will learn more about this phenomenon to follow.
What is Power Quality?
How to you define the term quality in an intangible entity such as electricity. Well let me tell you that quality in case of electric power means that the power is supplied at the designated voltage, amplitude and frequency without much variation in any of its major parameters.
Quality is important since the equipments are designed to work for a specific range of values such as voltage, current and so forth. Of course most equipment can withstand slight variations in these parameters but any substantial change could result in temporary or permanent damage to the equipment, which in turn would damage the data/information and that would ultimately trickle down as financial loss and reputation damage of the organization.
Parameters of Quality and their Impact
If quality is so important we must understand what all parameters constitute quality and what can be the impact of variation of these beyond a tolerable range, and some of the important parameters are defined below.
Voltage: AC power has got an peak voltage and RMS voltage and both these are important parameters. Any abnormal increase or decrease in this voltage is known as swell and dip respectively and both of them are undesirable as this can lead to component failure or burning. Closely related terms are spike, surge and flicker and refer to different patterns and time frames of voltage variation. Electric motors are very much susceptible to damage though such voltage surges and this could lead to overheated windings and failure of winding insulation. Moreover these motors themselves could be a cause for voltage dip to other electronic equipment since they require several times more current during starting than compared to their normal running current, hence the need for proper provision for taking care of the starting current.
Radio Frequency Interference or RFI: there can be noise present in the electric supply line which may not be seriously damaging for the electronic equipment but could result in disruption of communication and related errors. This noise results in low signal strength and is closely related to the next factor namely harmonics.
Harmonics: these refer to the currents which are in integer multiples of the basic line frequency and the presence of harmonics can cause several faults such as false triggers in the electronic circuits and so on. This factor is not much of an issue in the modern day equipments as most of them have a power factor correction design which is mandatory due to appropriate regulations of the governing bodies.
Methods of Improve Power Quality
As an end user a customer such as the data center or any other organization for that matter, does not have a direct control over the performance and quality of the power supply given by the utility company. Yet there are several techniques available to check monitor and control the quality of the incoming power supply.
One such method is the use of appropriate equipment and paraphernalia to ensure power quality. These equipments could include voltage regulators, surge protectors and so on. These equipments help to isolate the sensitive and costly IT equipment from the power grid by acting as a buffer which absorbs sudden shocks in terms of voltage fluctuation and surges. There are also other equipments such as MCB fuses which trip off whenever there is a possibly dangerous situation so that the equipment is saved from damage. Lightning arrestors are used to prevent power spikes in case of thunderstorms by absorbing the lightning current and passing them to the earth.
Power monitoring should be carried out and data should be stored for long term analysis and this gives a fairly good indication of the level and status of the quality of power available at the grid in a given area over a period of time. This monitoring could give useful advantage to the management in order to predict certain times when power quality is least so that appropriate measures and steps can be taken to ensure minimizing its impact.
Poor power quality may not seem to be a big problem at the first instance but surveys have revealed that in the United States alone, nearly 150 billion dollars were lost directly or indirectly as a result of failed equipment and lost data due to power supply of poor quality. This figure should be sufficient to give an idea about the seriousness of the problem and the need for adopting appropriate remedial measures by the data center managements.
Moreover it has been observed that the reliability provided by a typical power grid is much less than the reliability required of a typical data center and hence there must be provision with the data center to cope up with this difference in reliability, the data center needs to invest in the appropriate equipment and arrangements to deal with power quality and power failure either in the form of a blackout of brownout. The data and critical operations handled by a data center are certainly far more important not only for the customers but also for the data center itself for its long term sustenance and reputation.