By George Senzere
SOUTH Africa is currently plagued by a fragile power grid that is putting tremendous pressure on business and the local economy. And the unfortunate reality is this will remain the status quo for the next few months, with various news outlets reporting expected load shedding till August.
However, it is not only the lack of power supply that is impacting businesses but also grid instability that leads to surges, spikes and brown outs which can all severely damage costly equipment and impact business continuity.
Uninterrupted Power Supply (UPS) solutions have become a well-established part of local organisations and households’ efforts to create some form of energy supply normality in times of load shedding and other interruptions.
But to understand and get the most from a UPS it is also important to contextualise its role within the overall stable supply of power during periods of interruption. For one, UPS solutions provide clean power which is critical when protecting critical and sensitive equipment.
Second, most UPSs run in conjunction with generator installations; it forms the important first part of realising continuous and clean power supply. It provides immediate and uninterrupted power during those first vital seconds or minutes until the generators take over, which in turn deliver electricity for prolonged periods of time.
Stand alone
In some instances, UPSs are the only power supply option. Generators are noisy which means that in regulated environments such as office complexes tit may not be allowed. Here, UPS solutions therefore play a bigger role as it will be the only source of power to critical systems during load shedding and other instances of power outages.
The logical question is then, will UPSs be able to handle the load so to speak? The short answer is yes, depending on the required load – therefore kilowatt power. A good UPS solution can support equipment for a prolonged period of time and at least four hours we normally experience during scheduled load shedding.
What this, however, will entail is installing a UPS solution with the requisite additional batteries that can be sized to support load of different sizes. And whilst it is a feasible solution, it can become very costly particularly if the business in question requires a considerable amount of power, say close to a megawatt for example.
Practically, an abovementioned UPS solution will be able to provide power to an office block and critical medical facilities such as theatres during load shedding. However, a factory line will need more than UPSs as it requires a massive amount of power to run optimally. Here, as mentioned, it is recommended that the UPS solutions is combined with generators.
Therefore, in order to gain the most out of your UPS investment, consideration must be given to its application and ultimately the load it must be able to support.
Clean power
A UPS is by design a provider of clean energy. As previously mentioned, it protects equipment against power supply instability due to its large input voltage window which allows for considerable fluctuation in power supply from the grid. Despite the fluctuation it will continue to provide clean energy to the equipment it is connected to.
There are a number of UPS topologies available, however, double online conversion offers the ultimate in clean provider. It receives the power from the grid, stores it in direct current and then coverts it back into indirect current which is then supplied to the connected equipment.
What this means is the power goes through a double conversion, ensuring that it is clean when supplied by the UPS. This is crucial when using critical and sensitive equipment and will contribute not only the use but longevity of these critical systems. With increased innovation we are also seeing other UPS operating modes improve efficiencies up to 99% while still providing class 1, no-break power protection for connected equipment.
Ultimately, UPSs offer more than meets the eye – it forms a fundamental part of a robust and stable power supply system and ensure that the electricity provided is clean, a very real consideration when protecting business assets.
- George Senzere is Solutions Engineering Manager, Schneider Electric
