An uninterruptible power supply (UPS) is a device that protects electronic equipment from power uncertainties. A UPS is a device that is interfaced between the electric network (connected to utility power) and the materials that need protecting.
The UPS allows the materials to be switched to emergency battery power for several minutes in case of electrical problems, in particular during:
Most electrical disruptions are tolerated by computer systems. However, sometimes they can cause data loss and service interruptions and even material damages.
The UPS helps to "smooth out" voltage, i.e. eliminate peaks that are over a certain level. When there is a power outage, the energy stored in the emergency battery keeps the power supply flowing to equipment for a small amount of time (normally for 5 to 10 minutes). Beyond the minutes of autonomy that the UPS supplies, this gained time also allows the equipment to be switched to other energy sources. Some UPSs can also be directly attached to the computer (e.g. with a USB cable) so that it can order its own shutting off in case of a power outage and thus avoid any data loss.
There are generally three types of UPSs:
The length of electrical protection by a UPS is expressed in VA (Volt-Ampere). Generally, for electrical protection during a 10-minute power outage, you must have a UPS with a capacity that is equal to the power of all the materials connected to the UPS multiplied by a factor of 1.6.
When choosing a UPS, it is also important to check the number of sockets it has.
Sometimes UPSs have connectors (USB, network, parallel, etc.) that make it possible to connect them with the CPU so that it can order its own shutting off in case of a prolonged power outage and backup all the work in progress.
For those companies where a constant supply of energy is of critical importance, it is possible to set up a series of UPSs in a room called the "self-sufficiency room".
These rooms are generally equipped with dozens or even hundreds of UPSs that are capable of providing an electrical supply during a power outage lasting several hours. "Self-sufficiency" rooms may also include a generator that can take over after the UPSs have run out of power.