Riello UPS Sentryum Active 3:3 15kVA

Product Description

The Sentryum S3T ACT 15 from Specialist Power Systems is Riello’s third generation of transformerless online uninterruptible power supplies. 

The Sentryum improves on Riello’s popular Multi Sentry series and has been developed making it much easier and more cost-effective to maintain thanks to its fewer components and connectors.

The Sentryum redefines the concept of flexible power protection by offering three different cabinet sizes to meet the varied needs of small data centres and mission-critical applications:

Active (ACT)

  • Footprint less than 0.35m2 and volume of 0.33m3 
  • 380mm x 850mm x 1025mm (W x D x H) 
  • 1 or 2 internal battery strings

The UPS is manufactured using state-of-the-art components designed to run flawlessly at temperatures up to 40oC. These include a dual-core DSP processor and three-level inverters that operate at high frequency (18 kHz). This ensures the Sentryum delivers full-rated power (kVA = kW 1 pf) with exceptional operating efficiency of up to 96.5% in online double conversion mode. 

Available as three-phase input and output, the UPS has a unique control system that reduces harmonic voltage distortion (<1% at resistive load and <1.5% at non- linear load). In addition, the Sentryum has high overload (125% for 10 minutes, 150% for 1 minute) and short circuit (270% for 200ms and 150% for 300ms) capacity, which enables it to handle sudden peak loads without needing to transfer to bypass.

Install up to 8 S3Ts together in parallel to scale capacity or build in redundancy (i.e. N+1 configuration). Closed loop system ensures the UPSs continue to function even if there is a disruption to the connecting cables. 

A revamped 5-inch colour touchscreen display panel clearly highlights crucial UPS measurements and operating statuses. While an innovative new LED status indicator automatically changes its colour (light blue, dark blue, yellow, red) depending on the operating mode and condition of the UPS.

Full range of user-controllable operating modes including:

  • Online
  • ECO (up to 99% efficiency)
  • Smart Active
  • Emergency (Standby Off)
  • Frequency Converter

The Sentryum range is suitable for use with sealed lead-acid (VRLA), AGM, GEL, open vent or nickel cadmium batteries, as well as alternative backup sources such as supercapacitors and lithium-ion batteries.

It incorporates sophisticated battery management systems, such as deep discharge protection and recharge voltage compensation, to ensure the best performance and operating life. Higher-powered (20A) battery chargers are available for longer runtime applications. 

The Sentryum incorporates USB, RS232, and RJ10 ports, plus various slots to insert parallel and network communications cards. It is compatible with the full range of Riello UPS networking and UPS management software, including PowerShield3 and PowerNetGuard.  

Specialist Power Systems are an approved sales partner to Riello UPS in the UK with expert technical knowledge. Call us on 01234 851155 to discuss your requirements and how we can help you find the right product and support.

Product Specification

Part No

S3T ACT 15

Capacity (VA / kVA)

15 kVA

Maximum Output (Watts)

15000 Watts

Form Factor




Run Time


Warranty Length

3 Years

Battery Type

VRLA AGM/GEL/NiCd/Li-ion/Supercaps









3 years

Optional Accessories

Here at Specialist Power Systems we offer a wide range of manufacturer specific accessories from a UPS Network Card through to an External Maintenance Bypass Switch. Please get in touch so we can ensure you get exactly what you need to stay protected.

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Maintenance Packages Available
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For more information, please call us on +44 (0) 1234 851155 or send us a message below.

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