A UPS also known as an Uninterrupted Power Supply is an electrical device provides clean power to a load when the input power source -typically the mains utility – is unstable or fails. The UPS provides complete protection from all input power disturbances without interruptions by means of one or more attached batteries and associated electronic circuitry. Sags, Spikes, transients, lightning effects, Noise, Harmonics, frequency fluctuations…. etc. which cause injuries, fatal damage, serious business disruption and/or data loss.
UPS’s are divided into three main classes as per EN62040-3. The Stand-by (Off-Line) Uninterrupted Power Supply is the simplest and the least expensive, then comes the Line Interactive type, which overcomes the major disadvantages inherent to the off-line unit, finally the Double Conversion (On-Line) UPS which provides the best power protection.