Protect Plus S500 250 - 600 kVA transformer-less UPS with 3-level IGBT technology


Protect Plus S500 is a monolithic transformer-less UPS that combines high AC/AC efficiency with compact footprint and flexible configurations. Its high level of performance, wide range of options and minimized operating costs, makes it the perfect solution to backup any business-critical load. Thanks to its full IGBT double conversion technology (VFI SS 111), Protect Plus S500 combines low input THDi with almost unity input power factor.

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Energy saving open

Due to its high efficiency, power consumption is very low. Over its product lifetime, the savings in terms of money and power are higher than older systems, making this a good replacement unit.

Optimized TCO open

Over the total lifecycle, TCO is optimized thanks to lower energy consumption and service costs

Higher availability open

Redundancy capabilities increase the availability of this device to the highest possible level

Scalability open

Parallel operation makes it flexible to adapt the capacity to changing load requirements
  • Capacity 250-600 kVA
  • Input Phases 3PH+N+G
  • Input Voltage 380V, 400V, 415V
  • Output Phases 3PH+N
  • Output Voltage 380V, 400V, 415V

The system can operate in Eco Mode and Smart Eco Mode efficiency then reaching up to 99%, which reduces the energy costs associated. Using Protect Plus S500 also means decreasing the production of waste heat and minimizing the air conditioning costs. This results in significant cost savings and contributes to reducing the carbon footprint of the installation.

The system is an ideal backup power solution for medium and large critical applications where the power consumption, the footprint and the maintainability are key factors.

The UPS can be wall-mounted or installed side by side or back to back.


  • Input PF >0.99 and THDi <3%*
  • AC/AC efficiency up to 99% in ECO mode*
  • Output PF up to 1 (kVA=kW) and load PF range between 0.5 inductive and 0.5 capacitive without derating
  • Up to 8 units in parallel
  • Static and maintenance bypass lines and switches always included
  • Up to 125% of permanent overload capability through the static bypass line
  • Dry contacts board (settable and pre-defined contacts both in input and output), Modbus (via RS232/485), free slot for SNMP card
  • 7" color touch screen display
  • Compatible with VRLA and Li-ion batteries
  • Battery strings settable from 32 to 44 VRLA battery blocks (12V each)*
  • Common battery string(s) configurable (with two UPS in parallel)
  • Frequency converter mode available*
  • Wide range of options: load bus synchronization, battery temperature sensor, IP21/31 enclosure, bottom cable entry, external battery switch, SNMP communication card
  • Operating temperature up to 40°C (can tolerate up to 50°C with power derating)

* Conditions apply


  • Easy installation, operation and maintenance: front access to the main components, for easy maintenance or inspection. Parallel upgrade is easy and simply requires a signal cable

  • Maximized savings in terms of footprint (m2), power installed (kVA), electrical system (cabling and protection devices) and power management (kW and cost)

  • Low input THDi and PF>0.99: no additional power-consuming input filters needed

  • Smart ECO mode: when the bypass voltage and frequency are within the predefined range, the inverter will operate in parallel with the static bypass line, for the harmonic compensation and PF correction, while the static bypass will be connected to the load

  • Intelligent Test Mode: This mode will let the UPS to be tested directly onsite during the commissioning or the preventive maintenance operations, without using external dummy loads, thus saving money and energy from the mains utility