UPS |
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uninterrupted and continued support for the load with its remaining capacity .
Data centre UPS systems often have a modular design , where one or more modules – each a complete , self-contained UPS unit – are assembled into a 19in racking frame . Because each module adds incrementally to the overall capacity , N + 1 redundancy can be achieved easily and cost-effectively . This modular approach yields two further benefits ; scaling to meet changing demand becomes easy , and maintenance can be performed without interrupting power to the load , simply by swapping a module .
These redundancy , scalability and maintainability benefits are just as desirable for server rooms , but such premises ’ more limited size may preclude the space overhead of racking system cabinets . If so , a better alternative is to use free-standing units , provided they have a compact footprint and can be paralleled together .
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A practical server room UPS solution |
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At this point , a profile of a UPS system with data centretype capabilities , but scaled to server room constraints , begins to emerge . UPSL ’ s PowerWave 5000 / TP gives a practical example of this profile . Physically , it is a low-weight three-phase tower system , offering capacities from 10kVA to 50kVA . It achieves a power density of up to 100kW / m 2 from a footprint of just 0.4m 2 at 50kVA ; ratings that suit it well to a space limited server room environment .
PowerWave 5000 / TP , designed for mid-size server rooms , networks , telecommunication systems and industrial processes
The UPS provides full load protection through its dual conversion online topology , and high availability through using redundant critical circuits which duplicate all its internal critical components and circuitry , and eliminate single points of failure .
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‘ Power quality and continuity , availability , efficiency , maintainability and scalability all remain as essential attributes .’ |
Up to 20 units can be paralleled , to increase unit-level redundancy and allow easy scaling . Redundant units can also be maintained without interrupting power to the system . Each PowerWave 5000 / TP UPS offers a choice of cabinet dimensions , allowing users to accommodate their ideal battery size . Autonomy can be further extended with additional battery cabinets , which match the UPSs in appearance . Maintenance-free VRLA or NiCad batteries can be used .
Energy use and running costs are minimised as transformerless UPSs can achieve an efficiency of up to 95.5 per cent over a wide load range . Further savings can also be made through ripplefree and optional temperaturecontrolled battery charging , which protects batteries and extends their life-time performance .
This type of UPS also has electrical characteristics that
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enhance their suitability in server room environments . An input power factor of near unity reduces input cable and fuse sizes , while an outstandingly low THDi of < 3 per cent saves unnecessary oversizing of gen-sets , cabling and circuit breakers . Input component lifetimes are extended , while interference with nearby equipment is eliminated .
In conclusion
Server rooms , and similarlysized applications such as communications centres and industrial control rooms , are smaller-scale than data centres , yet they require the same level of power protection and security . Power quality and continuity , availability , efficiency , maintainability and scalability all remain as essential attributes of the UPSs they use .
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42 | February 2017 |