UPS Topology

“Voltage and frequency independent” UPS in compliance with IEC 62040-3, as well as online or double conversion, offers superior protection against power supply problems. Here, the input voltage is fed to a rectifier, with output being supplied by an inverter. Under normal operating conditions, the inverter receives its supply directly from the rectifier, and, when the power supply fails it is supplied directly from the batteries. Consumers have no direct connection to mains AC power supply; the UPS protects them from all power grid problems. In critical situations and with sensitive equipment, the protection ensured by VFI technology is highly recommended.


  • Sinusoidal input current and output voltage
  • No switching times, therefore no gaps in coverage
  • Frequency converter operation possible
  • Additional internal redundancy switch over
  • Optimum protection against power disturbances


  • Lower efficiency in comparison to VI technology
  • More cost intensive in comparison to VFD technology

  • Protect C

    • 1 - 10 kVA
    • Online / Double Conversion (VFI)

    Protect C is a true VFI / double conversion online UPS. The ECO and frequency inverter operation modes highlight the requirements for a modern versatile UPS. Protect C series is also available on request as a rack mount version as well as a version with longer battery backup time.

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  • Protect D

    • 1 - 10 kVA
    • Online / Double Conversion (VFI)
    • For tower and rack usage

    Highly efficient with a compact design, Protect D achieves more than 20% higher power in comparison to conventional UPS systems. Providing outstanding performance, superior reliability and longer autonomy times, Protect D also offers multiple communication options, advanced battery management and graphical control in one modular unit.

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