Reliable power for a sustainable world

Power Range: 100 - 800 kVA

The Master HE series from 100 to 800 kVA are the Riello UPS solution for installations requiring high energy efficiency and maximum power availability. Master HE Series provides maximum protection and power quality for data centres and industrial loads. The UPS has an IGBT-based rectifier, DSP (Digital Signal Processor) technology and provides true-line, double conversion power protection, (VFI SS 11 - Voltage and Frequency Independent in accordance with IEC EN 62040-3).

Master HE 300-400
Master HP & HE details


  • High efficiency up to 95.5% in double conversion 

  • kW = kVA (pf 1) up to 40°C

  • Galvanic Isolation

  • Peak shaving

Brochures and data sheets

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Master HE

100-800 kVA

Technical specifications of the model

MASTER HE - High Efficiency

Master HE series is available from 100 to 800 kVA. The UPS features a new ON LINE double-conversion technology utilising IGBT and DSP (Digital Signal Processor) control to provide maximum protection, power quality and green energy for any type of application including data centres, disaster recover sites, telecoms rooms, industrial processes and security applications.

High efficiency stands for higher active power available if compared with legacy UPS thanks to output unitary power factor (up to +25% if compared unity with same UPS at p.f. 0.8). Nominal power is granted with no downgrading independently from operating temperature in the range 10-40 °C. Furthermore, control circuits and specifically designed firmware grant outstanding ON LINE double conversion efficiency up to 95.5%, comparable with the best transformer-free UPS available on the market.

Zero Impact Source 

Master HE series UPS have zero impact on the power supply source, whether it is a mains grid or generator set:

  • input current distortion <3%;
  • input power factor 0.99;
  • power walk-in function that ensures progressive rectifier start up;
  • start up delay function, to restart the rectifiers when mains power is restored if there are several UPS in the system.

Smart Grid Ready

Being Smart Grid Ready, Master HE allows for the implementation of power accumulation solutions, and at the same time ensures extremely high levels of efficiency. It is also able to independently select the most efficient operating method based on the status of the grid.
Master HE UPS are also able to electronically interface with the energy manager using the smart grid communication network.

Battery Care System

Master HE series UPS include a range of features designed to prolong battery life and reduce their usage such as different recharging methods, deep discharge protection, current limitation and voltage compensation according with battery room temperature.

Thanks to the STEP-UP/STEP-DOWN converter, that provides to recharge and discharge the battery, the current ripple in the battery is extremely reduced; this arrangement enhance the battery reliability since it is no longer connected to the UPS DC bus. 

Main features

  • High efficiency up to 99.4% (STANDBY ON Mode);
  • Compact size: e.g.: only 0.85 m2 for the Master HE 250 kVA;
  • Reduced weight for tranformer based UPS;
  • Double load protection, both electronic and galvanic, towards the battery.