Othonos 39, 17343
Agios Dimitrios Athens
09:00 - 17:00


Fax: +30 210 9969444



On Line UPS

The Sentryum 10 – 40 KVA/kW offers the best combination of power availability, energy efficiency and global performance ensuring installation and running cost savings.

It is the very latest Riello UPS development resulting in a third-generation transformer-free UPS, originally introduced into the market over twenty years ago.

This ultimate solution is rated at output power factor 1 and defined as ON LINE double conversion technology in accordance with VFI-SS-111 classification (as set out in standard IEC EN 62040-3).

The Sentryum series is a transformer-free UPS available in 10-15-20 KVA/kW models with three-phase/single-phase input and single-phase output, and 10-15-20-30-40 KVA/kW models with three-phase input and output.


Technical Specifications

Product Brochure

Product Video


Modern guidelines and sustainable best practices direct us to conceive and design UPS with particular focus on the entire product life cycle, therefore applying ultimate but resilient technologies, recyclable materials and miniaturisation of assemblies whilst ensuring the systems global reliability, which is pivotal for any UPS. The internal card layout has been optimised to reduce the number of components, to reduce the number of interconnections and to reduce the space required, whilst at the same time increase global reliability and Mean Time Between Failures (MTBF) and to minimise operational expenditure such as service operations and maintenance costs.

The result is an outstanding range of three different solutions providing powerful but compact designs as follows:

Compact: less than 0.25 square meters and only 0.17 cubic meters of volume.

Active: less than 0.35 square meters and only 0.33 cubic meters of volume.

Xtend: less than 0.4 square meters and less than 0.5 cubic meters of volume.

High efficiency

Sentryum is a true ON LINE double-conversion UPS system providing the very highest levels of power availability, flexibility and unrivalled energy efficiency with superior performance for any small Data Centre and mission critical applications.

With a full power rating (kVA=kW unity pf), the Sentryum provides the maximum available power without any de-rating. Thanks to the three-level IGBT inverter topology (constructed using modules rather than discrete components) and innovative digital control, the Sentryum provides up to 96.5% overall efficiency, whilst maintaining a reduced number of components, connections and ribbon cables, which increases the overall system reliability, thanks to a higher MTBF.

Riello’s advanced average current mode digital PFC control and State-of-the-art three-level NPC inverters working at high frequency (18 kHz), contributes to minimise the UPS’s impact on the grid and hence reducing the overall operational costs and energy bills.

  • Start-up delay function, to sequentially restart the rectifiers once the mains power supply is restored if there are several UPS within the overall system
  • In addition, Sentryum provides a filtering and power factor correction function within the power network upstream of the UPS, thus eliminating harmonic components and reactive power generated by the power utilities.

Sentryum applies a zero impact onto its power source, whether this is from the mains power supply or a generator, this results in:

  • very low input current distortion <3%
  • near unity input power factor 0.99
  • power walk-in function that ensures progressive rectifier start up
  • start-up delay function, to sequentially restart the rectifiers once the mains power supply is restored if there are several UPS within the overall system
  • in addition, Sentryum provides a filtering and power factor correction function within the power network upstream of the UPS, thus eliminating harmonic components and reactive power generated by the power utilities.

High power availability

Sentryum’s fully rated design delivers full power (kVA=kW) regardless of the load power factor or operating temperature (full rated power is available up to 40 °C).

Furthermore, Sentryum’s advanced digital control makes it possible to deliver up 250% inverter current for 200 msec and 150% for 300 msec. The high overcurrent availability enables the system to deal with sudden peak loads (without static bypass intervention) and provide the short circuit current if required during operation on battery.

The innovative input stage design provides extremely high battery recharging current, whilst at the same time an energy efficient conversion process during battery operation to reduce the power wasted and to increase the autonomy time compared to legacy DC/ AC converters.

Smart Battery Management

Proper battery care is critical to ensure the correct operation of the UPS during emergency conditions. The Riello UPS Smart Battery Management consists of a series features and capabilities to optimise battery management and obtain the best performance and operating life possible.

Battery recharging: Sentryum is suitable for use with conventional hermetically sealed lead-acid (VRLA), AGM and GEL batteries, Open Vent and Nickel Cadmium batteries.

Sentryum is also compatible with ultimate alternative backup power sources such as Li- Ion batteries and Supercapacitors.

Superior battery charging current availability, ie up to 20 Amperes for the 20 kVA/kW power range, meaning that the Sentryum can be utilised within any extended battery autonomy application.

Depending on the battery type, different charging methods are available:

  • One-level voltage recharge, typically used for widely available VRLA AGM batteries
  • Two-level voltage recharge according to IU specification
  • Cyclical recharge system to reduce electrolyte consumption and lengthen the life of VRLA batteries.

Recharge voltage compensation based on ambient temperature to prevent excessive battery charging or overheating.

Battery tests to diagnose in advance any reduction in performance or problems with the batteries.

Deep discharge protection: during extended low-load discharges, the end-of-discharge voltage is increased – as recommended by battery manufacturers – to prevent damage or reduced battery performance.

Ripple current: recharge ripple current (residual AC component at low frequency) is one of the main causes of reduced reliability and battery life. Using a high frequency battery charger, Sentryum reduces this value to negligible levels, prolonging battery life and maintaining high performance over a long period of time.

Wide voltage range: the rectifier is designed to operate within a wide input voltage range (up to -40% at half load), reducing the need for battery discharge and thus helping to extend battery life.


With its flexible range of three solutions, configuration, performance, accessories and options, Sentryum is suitable for use in a wide range of applications:

  • suitable for powering capacitive loads, such as blade servers, without any reduction in active power from 0.9 lead to 0.9 lag
  • ON LINE, ECO, SMART ACTIVE and STANDBY Off operating Modes – compatible with centralised power systems (CSS) applications.
  • Frequency Converter Mode
  • Cold Start to switch on the UPS even when there is no mains power present
  • S3T 20 XTEND version: cabinet (440 x 850 x 1320 mm WxDxH) for optimised solutions when medium to long-term runtimes are required (up to one hour back up time for a 20 kVA/kW at typical load rate)
  • parallel configuration up to 8 units for three phase version
  • optional temperature sensor for external battery cabinets, to assist recharge voltage compensation
  • high power battery chargers to optimise charge time in the event of long runtimes
  • dual input mains power supply (not applicable on Compact, optional for Active, standard on Xtend version)
  • isolation transformers for modifying the neutral earthing (separate power sources), or for galvanic isolation between the input and output (optional inside Xtend, external for Compact or Active versions)
  • mechanical fitting for a higher rating of IP protection either IP21 or IP31 on Xtend version
  • Air filter on Xtend version door to protect UPS placed in dusty environment
  • compatibility with alternative backup energy sources rather than lead batteries (NiCd or Li-ion batteries or supercapacitors)
  • different sized battery cabinets and capacities, for extended runtimes

Advanced communications

Sentryum is equipped with a coloured graphic touch screen display providing UPS information, measurements, operating states and alarms in different languages.

The default screen displays the UPS status, graphical indication of the energy path through the UPS and the operational condition of the various assemblies (rectifier, batteries, inverter, bypass) within the UPS.

Furthermore, the user interface includes a UPS status led bar which delivers immediate and clear information regarding the overall status of the UPS by changing the colour (might be light blue, dark blue, orange and red) according with the operating mode and condition.

  • Advanced multi-platform communications for all operating systems and network environments: PowerShield3 monitoring and shutdown software included for Windows operating systems 10, 8, 7, Hyper-V, 2019, 2016, 2012, and previous versions, Mac OS X, Linux, VMWare ESXi, Citrix XenServer and other Unix operating systems
  • Compatible with RIELLO CONNECT (remote monitoring service)
  • RS232 serial on RJ10 connector and USB ports
  • 2 slots for the installation of optional communications accessories such as network adaptors and volt free contacts etc
  • Embedded contact interface which includes 5 programmable inputs and 4 programmable outputs
  • REPO Remote Emergency Power Off for switching off the UPS via a remote emergency button
  • Graphic display panel for remote connection.


S3M 10 ACT

S3M 10 XTD

S3M 15 CPT

S3M 15 ACT

S3M 15 XTD

S3M 20 CPT

S3M 20 ACT

S3M 20 XTD

S3T 10 CPT

S3T 10 ACT

S3T 10 XTD

S3T 15 CPT

S3T 15 ACT

S3T 15 XTD

S3T 20 CPT

S3T 20 ACT

S3T 20 XTD

S3T 30 ACT

S3T 30 XTD

S3T 40 ACT

S3T 40 XTD

Rated Voltage 380-400-415 VAC three-phase + N / 220-230-240 VAC

single-phase + N

380-400-415 VAC three-phase + N  
Rated frequency   50/60 Hz  
Voltage tolerance   40 – 72 Hz 400 ±20% @ full load
Power factor @ full load   0,99  
Current distortion   THDI ≤ 3%    
Rated Voltage 220-230-240 VAC single-phase+ N 380-400-415 VAC three-phase + N  
Number of phases 1 3 + N  
Voltage tolerance (Ph-N)   180 – 264 VAC (selectable)  
Rated frequency   50 ή 60 Hz (selectable)  
Frequency tolerance   ±5% (selectable)  
Bypass overload   110% infinite, 125% for 60 min, 150% for 10 min  
Nominal power (kVA) 10 15 20 10 15 20 30 40
Active power (kW) 10 15 20 10 15 20 30 40
Power factor   1 έως τους 40 ° C  
Number of phases 1 3 + N  
Rated Voltage (V) 220-230-240 VAC  single-phase + N  (selectable) 380-400-415 VAC three-phase + N  (selectable)  
Voltage stability   ± 1%  
Voltage distortion   ≤ 1% with linear load / ≤ 1,5% with non-linear load  
Frequency   50/60 Hz  
Frequency stability on battery operation   0,01%  
Type   VRLA AGM/GEL/NiCd/Li-ion /Supercsps  
Recharging method   One level, Two level, Cyclic recharge (selectable)  
Weight without batteries (kg)


48 / 72 / 103 50 / 74 / 105 52 / 76 / 107 48 / 72 / 103 50 / 74 / 105 52 / 76 / 107 78/112 82/116
Dimensions  (WxDxH) (mm)   280 x 840 x 700 (CPT version) / 380 x 850 x 1025 (ACT version)/440 x 840 x 1320 (XTD version)  
Communications   2 slots for communications cards / USB / RS232/ 9 signal contacts  
Operating temperature   0 – 40 ° C  
Humidity   5-95%  non-condensing  
Color   Anthracite grey RAL 7016  
Noise level at 1 m [dBA ±2],

(Smart Active mode)

  < 40 dBA  
IP rating   IP20  
Smart Active efficiency   up to 99%  
Standards   European Directives: L V 2014/35/CE low voltage Directive

EMC 2014/30/CE electromagnetic compatibility Directive

Standards: Safety IEC EN 62040-1; EMC IEC EN 62040-2 C2

Classification in accordance with IEC 62040-3 (Voltage Frequency Independent) VFI – SS – 111

Moving the UPS   Castors / Pallet  










Download the Pdf here







Watch the video here.                                                                Watch the video here.






Watch the video here.                                                           Watch the video here.






Watch the video here.                                                               Watch the video here.







Watch the video here.