What does a UPS do?
A UPS protects equipment and processes that depend on a reliable power supply. Examples include servers, network equipment, point-of-sale systems, controls, test stations and security technology.
The intended response depends on the application. A UPS may only need to bridge a brief voltage dip. In other cases, it must provide enough time for an orderly shutdown or for a process to reach a safe state.
What happens during a power failure?
When mains power fails, the UPS energy store takes over. An inverter provides the output voltage needed by the connected equipment. The available time depends mainly on the load and battery configuration.
A UPS is not automatically a replacement for a standby generator. It bridges the time required by the planned response: until mains power returns, a generator takes over or the connected systems shut down safely.
What types of UPS are available?
VFD, VI and VFI UPS systems differ in how strongly their output depends on the mains supply and how they respond to disturbances. A VFI UPS provides a high degree of isolation for sensitive equipment. A different class may be suitable for a less critical application.
The highest class is not always the right choice. Mains quality, the connected equipment, permitted transfer time, efficiency, noise, installation site and budget all matter.
What should be clarified before selecting a UPS?
For an initial assessment, ERREPI needs the connected equipment, its actual or estimated power consumption and the required backup time. Form factor, electrical connection, installation site, monitoring, bypass and maintenance requirements also affect the choice.
The UPS lexicon explains the technical terms. If you are already planning a specific system, start with UPS consulting.