uninterruptible power supplies

A constant clean source of power is something that many of us take for granted in modern society. As the world becomes ever more reliant upon technology for all aspects of day to day living, the demand for a constant clean power supply continues to grow. This is why in recent year's uninterruptible power supplies have become an ever more important part of both business and domestic electrical setups.

What does it do?
Simply put a UPS system is designed to provide constant clean power to any electrical equipment. It is installed between the mains power supply and the piece of equipment (also known as the critical load) it is protecting. They tend to be installed on systems including computers, data centres and all other sensitive technological equipment. Though all UPS are different they do have two common functionalities, these are as follow -

• Clean power provision - Power is by definition variable, as such there are often fluctuations in both quality and level of power that is provided through a power grid. There are many types of these fluctuations including spikes, surges and sags. The UPS system is designed to combat the damaging effects of these fluctuations by acting as a barrier between the equipment and the power supply.

• Power Backup - In the event of a complete power failure a UPS will use a system of batteries to provide power to the critical load. Unlike a standby generator an uninterruptible power supply is not designed to supply constant backup power in a power failure but is able to provide enough power to shut down the equipment it's protecting safely.

Typical UPS Systems
All uninterruptible power supplies systems have to be tailored to the critical load they are protecting however as a general guide there are three main types of UPS available.
Offline - These systems are the cheap entry level option of protection; however they are less advanced than other systems. Electricity will run through the unit and if a fluctuation is detected the system will turn on and provide protection.

Line interactive - These operate in a similar manner to offline but offer better protection against power fluctuations with more advanced power filtering.
Online - Unlike the other systems an online system's inverter (responsible for AC output) is constantly active providing clean constant power. If the inverter stops working it can drop back to mains until fixed without any problems being caused to the critical load.