Five Interesting Facts about Uninterruptible Power Supplies
Five Interesting Facts about Uninterruptible Power Supplies (UPS)
Uninterruptible Power Supplies are critical for business and a worthwhile backup for many others. Here are five interesting facts about the humble UPS.
- 1. John Hanley completed the first Uninterruptible Power Supply in 1934 in the USA. He patented it as an “Apparatus For Maintaining An Unfailing and Uninterrupted Supply of Electrical Energy”. A great innovation, but a bit of a mouthful.
- 2. The world’s largest UPS is the 46-megawatt Battery Electric Storage System (BESS), in Fairbanks, Alaska, USA, which powers the entire city and nearby rural communities during outages. It was first switched on in 2003 and the battery can provide 40 megawatts of power – enough for around 12,000 people – for up to seven minutes. This is more than enough to account for most of the power cuts Fairbanks suffers from.
- 3. The first UPSs were of rotary design, which utilised a flywheel to provide short intervals of backup power.The flywheel system stores energy by constantly spinning a flywheel. If the power fails, a reliable source of DC power is then delivered by using the kinetic energy stored in the high-speed flywheel. Sometimes the flywheel is even used today. This is because while the flywheel can only produce a high power output for short durations (20-90 seconds), some businesses are now incorporate them into their standby power systems because a flywheel can have a smaller footprint than a battery bank. Flywheels are also seen as ‘greener’ technology because they eliminate the need to use energy to cool batteries, and have an average lifespan of 20 years.
- 4. The three most common types of Uninterruptible Power Supplies online double-conversion, line-interactive, and offline/standby. In an online double-conversion UPS, the batteries are always connected to the inverter, so that no power transfer switches are necessary. Double-conversion UPSs are thesafest, but most expensive kind of power protection. The line-interactive UPS is similar in operation to a standby UPS, but with the addition of a variable voltage autotransformer. The offline/standby UPS (SPS) offers only the most basic features, providing surge protection and battery backup.
- 5. The most common reason for UPS failures is their batteries. UPS batteries need to be consistently maintained to provide the maximum reliability. The most detrimental environment a battery can be placed in is one that is too hot. Considering a UPS, as well as the batteries themselves, produces a lot of heat, air conditioning is in order.