Riello UPS Sentinel Tower

Sentinel Tower (STW) is your ideal solution to protect non-linear loads found in IT systems, telecoms networks and security/safety systems. High-performing three-level inverter delivers unity power factor and 95% operating efficiency.

Increase power or redundancy by paralleling up to 3STWs together. Boost efficiency to 98% with dedicated ECO or Smart Active operating modes. Can be used with both single-phase and three-phase input supplies.

  • 95%operatingefficiency(ON LINE mode)reduces energy waste
  • Unity power factor provides full power output (kVA=kW)
  • Parallel up to 3 UPS for extra capacity or redundancy
  • Load-controlled fan speed minimises noise (<45 dBA)
  • Designed to handle non-linear loads so ideal for blade servers

Riello UPS Sentinel Tower Information

High UPS reliability

  • Total microprocessor and DSP control
  • Interruption-free static and manual bypass
  • Specifications guaranteed up to 40°C (the components are designed to work at high temperatures and thus are subject to less stress at normal temperatures)


Parallel configuration of 3 units for (2+1) redundant or power parallel system. The UPS continue to operate in parallel even if the connection cable is interrupted (Closed Loop).

Unity Power Factor

  • More power delivered
  • More real output power (W)

Operating mode selection

The operating mode can be programmed via software or manually via the front display panel.

  • ON LINE: efficiency up to 95%
  • ECO Mode: to increase efficiency (up to 98%), allows for the selection of LINE INTERACTIVE technology (VI) to power low priority loads from the mains supply
  • SMART ACTIVE: the UPS automatically decides upon the operating mode (VI or VFI) based on the quality of the mains power supply
  • STANDBY OFF: the UPS can be selected to function only when the mains power supply fails (emergency only mode)
  • Frequency converter operation (50 or 60 Hz)

High-quality output voltage

  • Even with non-linear loads (IT loads with a crest factor of up to 3:1)
  • High short circuit current on bypass
  • High overload capacity: 150% by inverter (even with mains failure)
  • Filtered, stabilised and reliable voltage (double conversion ON LINE technology - VFI compliant with EN62040-3), with filters for the suppression of atmospheric disturbances
  • Power factor correction: UPS input power factor close to 1 and sinusoidal current uptake

Simplified installation

  • UPS can be installed on a single-phase or three-phase distribution network STW 8000 and STW 10000
  • Output terminal board + 2 IEC sockets for powering local consumers (computers, devices, etc. )
  • Simplified positioning (built-in castors)

High battery reliability

  • Automatic and manual battery test
  • Proper battery care is critical to ensuring correct UPS operation in emergency conditions. The Riello UPS battery care system consists of a series of features and capabilities to optimise battery management and obtain the best performance and operating life possible
  • Unlimited extendible runtime using matching Battery cabinets
  • The batteries do not cut in during mains failures of <20 msec. (high hold up time) or when the input supply is between 184 V to 276 V.

Low impact on the mains

Sinusoidal uptake of input current on single-phase/single-phase series.

Runtime expandability

Optional battery extension packs can be connected to increase UPS runtime. In addition, the Sentinel Tower range includes ER versions with no internal batteries and more powerful battery chargers 6 A for longer runtimes.

Other features

  • Advanced diagnostics: status, measurements and alarms available on new custom LCD display
  • Low noise (<45 dBA): can be installed in any environment thanks to its high frequency switching inverter and PWM load-dependent digitally controlled fan (>20 kHz, value above audible range)
  • Auto-restart (automatic when mains supply is restored, programmable via software
  • Back-feed protection standard: to prevent energy from being fed back to the network
  • UPS digital updating (flash upgradeable)

Advanced communications

  • Compatible with Riello Connect remote monitoring
  • Advanced multi-platform communications for all operating systems and network environments: PowerShield³ monitoring and shutdown software for Windows operating systems 10, 8, 7, Hyper-V, 2019, 2016, 2012and previous versions, Mac OS X, Linux, VMWare ESXi, Citrix XenServer and other Unix operating systems
  • RS232 serial and USB ports
  • Plug and play function
  • Slot for installation of communications boards


Price Promise
We always aim to be competitive and will look to beat any existing quotation you may have.
Please email or call us today.
Book a site survey
To discuss your power protection requirements, or to arrange a site survey, please click the button below to contact us or to complete a form.
Contact us today
© Computer Power Protection 2024 All rights reserved
Top crossmenu