Riello UPS Multi Sentry MST

Riello's transformerless monolithic three-phase UPS, current only at 160 and 200 kVA since Sentryum arrived

This model is part of SecondWatt’s ups system research catalogue. Specifications and price observations are included where supported by sources. Equipment availability and commercial terms require confirmation.

Riello Multi Sentry MST dossier: 160 and 200 kVA at unity power factor, VFI-SS-111, 96.5% efficiency, used-market findings and a full inspection checklist.

Why it matters

Multi Sentry is the cleanest published example of cabinet-versus-battery pricing in the category. Critical Power Supplies sells two distinct MST 100 SKUs, one with an internal battery set and one explicitly without internal batteries, and Energom states for the MST 100 that the unit has an internal battery compartment but the battery price is not included. That is the rule written into a manufacturer channel's own catalogue.

Who buys it

UK and European facilities managers replacing or extending an installed Multi Sentry fleet, and dealers holding used MST stock for that market. Buyers below 160 kVA are effectively shopping the Sentryum successor line instead. North American buyers have no path to this product, since it carries no UL listing and no US service channel.

Role in the data center

Room-level or facility UPS in European computer rooms and small data halls, feeding the critical distribution board from a 380/400/415 V four-wire supply. Up to six units parallel for redundancy in a distributed architecture, with the battery string external or in the cabinet's own compartment depending on the SKU.

Key specifications

Technical summary

Current ratings: MST 160 at 160 kVA/160 kW; MST 200 at 200 kVA/200 kW, unity power factor. Legacy ratings: MST 10 to 125 kVA, superseded by the Sentryum line. Input: 380/400/415 V three-phase plus neutral, 40-72 Hz, input PF 0.99, iTHD at or below 2.5%. Output: 380/400/415 V three-phase plus neutral, plus or minus 1% regulation. Efficiency: 96.5% double conversion; up to 99% in eco and Smart Active. Topology: transformerless monolithic, three-level NPC inverter. Parallel: up to 6 units, distributed parallel redundancy with Closed Loop architecture. Dimensions: 850 x 1050 x 1900 mm on MST 160-200; 135-460 kg without batteries. Battery: VRLA AGM, GEL, NiCd, lithium-ion, supercapacitors; 240 VDC nominal on MST 160/200. Standards: IEC EN 62040-3 VFI-SS-111; IEC EN 62040-1; IEC EN 62040-2 class C2.

Major variations

Riello lists Multi Sentry as current only at MST 160 and MST 200, both 160 kVA/160 kW and 200 kVA/200 kW at unity output power factor. The historic family ran MST 10, 15 and 20 in 1:1, 3:3 and 3:1 configurations and MST 30, 40, 60, 80, 100 and 125 as 3:3 units at 0.9 power factor, so an MST 30 is 27 kW. Those ratings are replaced by Sentryum, which Riello describes as its third generation of transformerless online UPS improving on the Multi Sentry series. Two battery configurations are catalogued at each rating: with an internal battery set, or as a socle-box build with no internal batteries.

Configurations and options

Two battery configurations are catalogued at each rating and they are the cleanest cabinet-versus-battery split in this category: a unit with an internal battery set, or a socle-box build carrying no internal batteries, sold as separate part numbers by Riello's own dealers. Rating is the next variable, with MST 160 and MST 200 current at unity power factor and the legacy MST 30 to 125 ratings at 0.9, so an MST 30 is 27 kW rather than 30. The MST 10, 15 and 20 were built in 1:1, 3:3 and 3:1 input and output configurations, which is a build choice rather than a setting. Also specified on the order: battery chemistry across VRLA AGM, GEL, NiCd, lithium-ion and supercapacitors, the 50 A recharge current option against the 25 A standard, and the three communication slots.

Compatibility and dependencies

Input and output are 380/400/415 V three-phase plus neutral in four wire, with input frequency tolerated from 40 to 72 Hz and output regulation within 1%. The two numbers that size the upstream feeder are maximum input current at 316 A on the MST 160 and 383 A on the MST 200. Batteries are external or internal depending on the build, on a 240 VDC nominal bus at these ratings, with temperature compensation and a battery test routine built in. Up to six units parallel in a distributed redundancy scheme Riello calls Closed Loop, which continues operating through an interruption of the parallel cable, and Power Share connections handle load shedding. The cabinet is 850 x 1050 x 1900 mm at 135-460 kg without batteries and emits 68 to 70 dB(A). EMC is declared category C2, a lighter classification than the C3 most large UPS carry.

Pricing and availability

Trend: rising Lead time, new: Quote-only; UK dealers show MST 160 and 200 in stock with limited availability. Lead time, used or refurbished: 2-8 weeks through UK and European dealers. Warranty, used: 1-year typical from refurbishment dealers.

Lifecycle and maintenance

Static UPS cabinets serve roughly 15 years, the figure Mitsubishi publishes alongside a lifecycle-parts-or-replace decision at 10-12 years. The wear items are documented: Eaton rates DC bus capacitors at 7 years of continuous duty and up to 10 in favourable conditions, Riello puts capacitor service life at 10 years with replacement recommended between years 4 and 8, and Vertiv field data gives 6 years for capacitors and 5-6 years or 40,000-50,000 hours for cooling fans. Batteries turn over far faster, at 3-5 years for sealed VRLA and 12-15 for flooded cells, and spent lead-acid leaves as regulated waste through compliant recycling rather than resale. Service life extension programs rebuild the power train inside the original shell, which is why cabinets routinely outlive their electronics.

Thermal and emissions profile

UPS systems produce no combustion emissions, so the regulatory profile is battery handling, efficiency reporting and fire code. VRLA cells are regulated lead-acid waste at end of life and route through compliant recycling rather than resale, which is why asset recovery firms treat cabinet and cells as two separate economies. ENERGY STAR version 2.0 sets the efficiency benchmark, requiring VFI units above 10,000 W to meet 0.0058 x ln(P) + 0.886 and every AC-output unit to hold at least 90% power factor at full load, measured as a load-weighted average at 25, 50, 75 and 100% load. Efficiency is itself the emissions lever, since each point of double-conversion loss is continuous waste heat the cooling plant has to reject.

Common failure points

• Battery strings — VRLA capacity fades below 80% of nameplate and takes the ride-through with it
• DC bus capacitors — Silent open-circuit loss, or a short that pops and sprays electrolyte across adjacent boards
• Cooling fans — Overheating transfers the load to bypass and leaves it unprotected
• Air filters and dust — Restricted airflow raises internal temperature and shortens capacitor life
• Static bypass switch — Failure to transfer strands the load during maintenance or overload
• Controls obsolescence — Discontinued display and logic boards turn a routine repair into a scavenger hunt

Inspection checklist

Battery age: sealed VRLA turns over at 3-5 years per Eaton lifecycle guidance; assume a full string past that. Battery capacity: reject any string below 80% of nameplate capacity under IEEE 1188 practice. Battery impedance: treat ohmic readings more than 20% above the commissioning baseline as an investigation trigger under IEEE 1188 field practice, then confirm against the battery manufacturer limit for the chemistry before condemning a cell. Float voltage: verify 2.23-2.27 VPC at 25 degrees C; float current above 3x steady state flags thermal runaway. Intercell connectors: thermal image every joint; a delta above 5 degrees C against neighbors triggers a capacity test. DC bus capacitors: Eaton rates 7 years of continuous duty (10 optimal); Vertiv field data gives 6 years at 45,000-50,000 h. Cooling fans: Vertiv field data gives 5-6 years or 40,000-50,000 hours; listen for bearing noise at the intake. Air filters: pull every filter; a clogged element is the best single proxy for a cabinet that ran above 25 degrees C.

Procurement channels

New units are quote-only through Riello's European channel; UPS Systems in the UK lists MST 160 and MST 200 in stock with a note that Riello stock levels are limited. UK and European dealers and auction houses carry used MST stock, generally unpriced. No North American refurbishment dealer stocks the line: Gruber Power Services names APC, Eaton, Liebert, MGE, Best Power, Tripp Lite and Xtreme on its refurbished brand list and no Riello.

Regional notes

IEC 400 V product not offered in North America. Riello's UL-listed products are Sentryum, Master HP UL, Master HP FC UL and Sentinel Pro2 UL, and US distributor lead times on those run 4-6 weeks for Sentryum and Master HP against 10-12 weeks for MultiPower2.