Uninterruptible Power Supplies – how much backup time do I need?
This content discusses the considerations for selecting an Uninterruptible Power Supply (UPS). It emphasizes the importance of determining the necessary backup time, noting that longer backup times increase both cost and space requirements for batteries. Key factors affecting backup time include the load supported by the UPS and the presence of a generator. For sites with diesel generators, a suggested autonomy of 10 minutes at full load is recommended, which also accommodates future growth. The text advocates linking a UPS with a generator for reliable power protection, stressing the need to maintain a full fuel tank for the generator.
So you may already have a UPS, or may be looking for one at the moment.
The golden question is how much backup time do you need?
As you would expect, the longer the backup time, the higher the cost. Along with that, the space required for the batteries will also increase. When talking about UPS of 100kVA and larger, the space required for the VRLA batteries can be substantial. The backup time depends on a number of different factors, including what the UPS is supporting, what the load is and whether there is also a generator. For sites where there is a diesel generator covering the whole building (or at least the load that the UPS is supporting) the general suggestion is for a 10 minute autonomy at 100% load. This is to make sure you allow leeway for future growth. For loads such as telephone switches or network switches, where the power draw is small, use a compact UPS/battery configuration. For a dependable power protection solution, it is advisable to always link a UPS and a generator. This will ensure you have uninterrupted power for your servers and other IT c ritical load. The generator will provides unlimited backup. Always remember to keep the f uel tank full.
