Frequent disturbances in mains and power outages can lead to companies incurring high IT service loss and equipment damage, cautions APC by Schneider Electric, a global leader in integrated critical power and cooling services.
While the need to reduce data centre power consumption and carbon footprint cannot be taken lightly, some of the approaches being taken to eliminate UPS electrical losses are highly questionable.
The comments were made by Shri Karve, Director of Business Development, APC by Schneider Electric, to highlight the fact that UPS which are designed to switch between various modes of operation (i.e., topologies) in order to increase energy efficiency may eventually compromise the protection of the IT equipment.
Shri Karve said: “The unrealistically high UPS efficiencies being quoted by a number of static UPS manufacturers can only be achieved by sacrificing the electrical power quality demanded by IT servers and by increasing the risk of unwanted source switching at a crucial moment of UPS operation.
“The operational switching between VFD (line interactive), VI (standby) and VFI (online double conversion) can impact system resilience due to prolonged switching periods. It can also reduce MTBF (Mean Time between Failure) causing very low availability values due to increased MTTR (Mean Time To Repair). Availability is a key metric for risk averse data centre owners and operators.”
The IMS Static Research, Uninterruptible Power Supply Sourcebook published in July 2010, says static UPS enjoys the lion’s share of a global UPS market and forecasted to grow to US$7.3billion in 2011. Moreover, those units are the preferred choice for protecting mission critical facilities such as data centres.
According to Karve, there are a number of key criteria to consider when selecting which type of UPS system will provide optimum protection at a competitive price. These include criticality, UPS type, configuration/ availability, load rating/ battery autonomy, maintainability and installation/ structural considerations.
Where data centres are concerned, the very first question is one of mission criticality – in other words, what are the consequences for an organisation if a mains disruption or outage crashes its computer network. Continuity of power and quality of power are essential to the reliable operation of IT equipment and the successful delivery of IT services.
Shri Karve added: “In certain modes of operation, some 3-phase UPS provide no better protection than the cheapest UPS you can find in a local PC store. What’s more, they expose IT equipment to raw mains power – a situation that no serious data centre operator would countenance under normal circumstances.”
Karve, a 40-year veteran of the UPS market and evergreen data centre conference speaker, calls for a small compromise on efficiency pointing out that while highly complex operational mode switching may momentarily achieve 99 per cent efficiency, Double Conversion (VFI) UPS are up to 97 per cent efficient.
APC by Schneider Electric offers modular and scalable models that will protect an IT load continuously against mains variations and outages such as APC Symmetra PX and Symmentra MW. With no switching risks, APC Symmetra provides a great deal of peace of mind in environments where IT continuity, resilience and efficiency are vital.
