Why is the sizing of ups important

International Site Map Change Country. Our tool will walk you through a step-by-step process and display UPS options that will fit your requirements.

Call us! We are here to help and our experts can provide you with the right UPS choices. Do it the old fashioned way! With a few simple questions and calculations, you can identify your power needs and find the right Eaton UPS.

Follow these steps below. List all equipment to be protected by the UPS. Remember to include monitors, external hard drives, routers, etc. Establish whether an item of equipment is critical — and therefore will need the emergency backup provided by the UPS — or non-critical, which can be allowed to fail when the mains power supply does so.

Learn more about the difference between critical and non-critical loads. The next step is to calculate the total power range for the combined critical load that needs protecting. Equipment labels and supporting technical data will provide information such as the supply voltage, frequency, number of phases, load current, power factor and power consumption. Add up all the VA, then multiply this by a figure such as 1. Certain equipment i.

If so, its contribution to the load in VA can be found by multiplying its load current by its supply voltage. Alternatively its power consumption in Watts can be divided by its stated Power Factor to reveal its VA load. This measurement activity can form part of the overall site survey. This should include installing portable measuring and monitoring equipment to record information about the load over a period of time.

The period depends on the site situation; for example it would be misleading to monitor an office network over a weekend when very few staff have their PCs on. The nature as well as the size of the load should be considered. Although UPSs are generally resilient, certain load types do present challenges which must be allowed for. These include blade servers, fluorescent gas discharge lighting, motors and compressors, air conditioning equipment and laser printers.

These can all draw high currents during normal operation, and even higher inrush currents during start-up. This may overload the UPS causing a transfer to bypass. Blade servers also impact UPSs in another way. Unlike equipment with a lagging power factor, blade servers present a leading power factor. This presents a major problem with legacy transformer based UPS systems.

By contrast, a modern transformerless kVA does not derate at 0. Harmonic currents, if present, cause increased reactive power and therefore degrade the power factor. This can drop to 0.