Uninterruptible Power Supply also known as UPS SYSTEMS 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 SYSTEMS provide a 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 SYSTEMS are divided to three main classes as per EN62040-3. The Stand-by (Off Line) UPS 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
Passive Stand-by UPS SYSTEMS
A Stand-by, also called off-line UPS or Backup, feeds the load continuously from Mains. Upon mains outage, the load connections transferred to the inverter fed from the batteries. By using special filters most of the short-term spikes surges and high frequency harmonics are applied in these units. While various phenomena of transient nature during mains existence, like over voltages can harm protected data.
Line Interactive UPS SYSTEMS
Line Interactive UPS, called sometimes Interactive UPS, or On Line Interactive UPS. For short backup times and shut down these units are sufficient.
Double Conversion UPS SYSTEMS with Bypass
Also called On-Line UPS, or True On-Line UPS, is the ultimate solution. All applications from 1 kVA up to 1 MVA sized consumers. The load is constantly fed from the Inverter, providing conditioned, stabilized sinusoidal voltage. The utility line in these systems forms a backup source in case of UPS malfunction. The Transfer switch will automatically transfer the load to mains in case of overload or UPS failure