Uninterruptible Power Supply

An uninterruptible power supply, often referred to simply as a UPS, is a device that is able to supply power to electrical equipment during a power outage for a certain amount of time. UPSs are often used in data centres to ensure the operation of essential components, such as servers, routers or telephone systems to use. Additionally, UPSs are also available for individual computers. Depending on the type and size of the system, the maximum backup time needed varies. Large professional data centre systems are usually dimensioned so that the power supply is assured until petrol or diesel emergency generators have time to kick in. Some systems provide the equipment with power for the time it takes them to shut down. This may be implemented through a mechanism that automatically shuts down the computer as soon as the UPS comes into action. UPS units for individual PCs will provide power for longer, depending on their battery capacity.

Regular testing of an Uninterruptible Power Supply

To ensure that a UPS actually works during a power outage, it must be subjected to a functional test at regular intervals. To this end, many systems have an automatic load test, whereby the battery will discharge at defined intervals, under load. Also, batteries must be replaced at regular intervals.

The components of an Uninterruptible Power Supply

The construction of a UPS can vary, but usually includes at least the following components:

  • Mains voltage monitoring that recognises power outages, surges, brownouts and critical frequency changes and activates the UPS.
  • Energy storage, usually a battery, which provides the energy for emergency use in case of power failure and is charged from the mains electricity supply during normal operation.
  • An inverter, which converts the DC power supplied by the battery into the required AC voltage.

Uninterruptible Power Supplies and cloud telephone systems

As cloud phone systems are operated in professional data centres, they are generally protected from power failures with a suitable UPS. In order for cloud telephone system users to remain unaffected by power outages they should make provision to ensure that all of the components required for telephony can continue to be supplied with energy from UPSs in the event of a break in the power supply. Equipment that should be protected includes routers, switches, PCs and IP phones.

Further information

IP phone

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