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Master HE (100 – 800 KVA)

Master HE (100 – 800 KVA)

On Line UPS

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 datacentres, 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 online double conversion efficiency up to 95,5%, comparable with the best transformeless UPS available on the market.


Technical Specifications

Product Brochure

Product Video

Maximised cost savings

The build specifications offered by the Master HE range and the exceptional level of efficiency help to absorb the TCO, from the installation stage to daily operation, reducing power costs for the UPS, air conditioning system and installation area costs thanks to its reduced size and weight.

Complete galvanic separation

Master HE UPS feature an output isolation transformer (delta zig/zag type) on the inverter as part of the inverter circuit inside the UPS cabinet, providing galvanic isolation between the load and the battery with improved versatility in system configuration, allowing:

  • Complete UPS output galvanic isolation for critical infrastructures from the battery DC power source;
  • two truly separated supply inputs (main and bypass), which can be taken from two different power sources (with different neutrals); this is particularly well suited to parallel systems in order to ensure selectivity between the two sources, thus improving the reliability of the entire installation;
  • No neutral input connection is required at the UPS rectifier input stage; this method is particularly favourable in order to prevent the transmission of common neutral disturbances via the neutral conductor;
  • No effects to the UPS output performance or reduced impact of the inverter power components whilst supplying specific loads; in addition the inverter transformer minimizes the impact of third harmonic disturbances, prevents the effects of energy back-feed into the inverter when supplying industrial load applications and can supply unbalanced loads.
  • High inverter short circuit current to clear faults which occur between phase and neutral on load side (up to three times nominal current).

Output transformer housed within the cabinet which allows for a significant reduction in the footprint and provides space savings.

Zero impact source

The Master HE series features the added advantages of the Zero Impact Source formula offered by an IGBT-based rectifier assembly. This eliminates problems connected with installation in networks with limited power capacity, where the UPS is supplied by a generator set or anywhere there are compatibility problems with loads that generate current harmonics. 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.

This provides savings in installation costs via:

  • a smaller electrical infrastructure.
  • smaller circuit protection devices
  • less wiring.

Master HE also performs the role of a filter and power factor corrector, protecting the upstream power supply from any harmonics and reactive power generated by the critical load.


Master HE is suitable for a wide range of applications including IT and the most demanding industrial environments and processes. With several operational configurations including On-Line, Eco,

Smart Active, Stand By, Frequency Converter and Voltage Stabiliser. A broad range of accessories and options, complex configurations and system architectures can be achieved to guarantee maximum power availability and the option to add new UPS without interruption to existing users.

Using the Riello UPS Group Synchroniser (UGS) and Parallel Systems Joiner (PSJ), sophisticated inter group parallel and redundant systems can be achieved to provide the highest possible levels of resilience and availability.

Battery care system: maximum battery care

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 UPS DC bus.


  • High efficiency up to 99,4% (stand by 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.

The entire Master HE range is suitable for use in a wide range of applications. Thanks to the flexibility of configuration, available options and accessories, it is suitable for supplying any type of load, e.g. capacitive loads such as blade servers, rather then motor drivers or any other critical vertical application.

Power supply reliability and availability are ensured for critical applications by distributed or centralised parallel configurations of up to 8 units, for redundant (N+1) or power parallel configurations and all the different configurations offered by the Master MPS range.

Smart Grid Ready

Being smart grid ready, Master HP 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.

Advanced supervision

Master HE series UPS have a front panel graphic display providing UPS information, measurements, status updates and alarms in different languages, with wave form displays including voltage/current and provide a KWh reading that can be used to measure IT loads and calculate a datacentre PUE (power usage effectiveness) ratio.

MODELS ΜΗE 100 ΜΗE 120 ΜΗE 160 MHE 200 ΜΗE 250 ΜΗE 300 MΗE 400 MΗE 500 MHE 600 MΗE 800


Nominal voltage 380 – 400 – 415 VAC 3-phase
Frequency 45 – 65 Hz
Power factor > 0,99
Harmonic current distortion <3% THDi
Soft start 0 – 100% in 120’’ (selectable)
Frequency tolerance ± 2% (selectable from ± 1% to ± 5% from front panel)
Standard equipment provided Back Feed protection; separable bypass line


Nominal voltage 360 – 400 – 420 VAC 3-phase + N
Frequency 50 or 60 Hz selectable


Nominal power (kVA) 100 120 160 200 250 300 400 500 600 800
Active power (kW) 100 120 160 200 250 300 400 500 600 800
Number of phases 3 + N
Nominal voltage   380 – 400 – 415 VAC three-phase + N (selectable)
Static stability ± 1%
Dynamic stability ± 5% in 10 ms
Voltage distortion < 1% with linear load / < 3% with non-linear load
Crest factor (lpeack/lrms) 3:1
Frequency stability on battery 0,05%
Frequency 50 or 60 Hz (selectable)
Overload 110% for 60’; 125% for 10’; 150% for 1’


Type  VRLA AGM / GEL; NiCd; Li-ion;
Ripple current Zero
Charge voltage compensation (-0,5) Vx°C


Weight (kg) 730 785 865 990 1090 1520 1670 2500 2830 3950
Dimensions (WxDxH) (mm) 800 x 850 x 1900 1000 x 850 x 1900 1500 x 1000 x 1900 2100 x 1000 x 1900 3200 x

1000 x


Remote signals volt-free contacts (configurable)
Remote controls ESD and bypass (configurable)
Communications Double RS232 + dry contacts + 2 slots for communications interface
Operating temperature 0 – 40 ° C
Relative humidity <90% non-condensing
Colour Dark grey RAL 7016
Noise level at 1 m  63 – 68 dBA 70 – 72 dBA
IP rating IP20
Smart Active efficiency > 99%
Double Conversion Efficiency up to 95,5%
Regulations  Safety: EN 62040-1 (Directive 2006/95/EC); EMC: EN 62040-2 (Directive 2004/108/EC)
Classification in accordance

with IEC 62040-3

(Voltage Frequency Independent) VFI – SS – 111









Download the Pdf here






Watch the video here.