Piller Power Systems UNIBLOCK UBT+ rotary UPS, 150 kW to 50 MW

Piller's mechanically coupled rotary UPS from 150 kW to 50 MW, now being displaced by the electrically coupled UB-V

Piller Power Systems UNIBLOCK UBT+ rotary UPS, 150 kW to 50 MW is one of 22 UPS systems tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.

Piller UNIBLOCK UBT+ dossier: rotary UPS from 150 kW to 50 MW, 97% efficiency, UB-V succession, parts and capacitor inspection points, and market context.

UNIBLOCK UBT+ is Piller's rotary hybrid UPS, covering 150 kW to 50 MW in the UNIBLOCK series with the diesel rotary UBTD+ sibling running 500 kW to 40 MW. Energy storage is an option between batteries and a POWERBRIDGE flywheel, cooling is air or chilled water, and containerized builds are available for low and medium voltage applications. Piller's own history page states real efficiencies at 97% for the 2008 to 2014 UBT+ and UBTD+ range. The generational point matters for residual value. UBT+ is a mechanically coupled legacy architecture, while Piller's current data center flagship is the electrically coupled UB-V Series at 1,100 kVA to 3,600 kVA, marketed as new with its own product pages. The UB-V reaches up to 98% at full load and 97% at half against a benchmark of 96.3% for conventional static UPS, claims a single-unit mean time between failures five times a typical static UPS, saves more than 20% of plant room space, and extends service intervals to once every five years using condition monitoring while carrying no power capacitors and no electric fans. That last claim is the inspection lead for a used UBT+. If the UB-V is differentiated by having no power capacitors and no electric fans, then UBT+ generation units do contain both, and both are finite-life consumables on a machine built between 2008 and 2014. Piller's after-sales organisation performs preventative maintenance to extend UPS life to at least twenty years and holds stocked parts at service centres worldwide, so parts risk is low relative to a discontinued third-party line.

Why it matters

Piller is a supplier whose new-build slots are sold out for 2026 and nearly all of 2027, with the parent reporting Power Solutions orders on hand of 1,952 million euros at the end of 2025 against revenue of 793 million. That is the classic condition that creates a secondary-market premium, and it is the same dynamic the four-tier framework describes for gas turbines applied to rotary UPS.

Who buys it

Large data center, industrial and institutional buyers who want a rotating machine in the power path with high fault current capability and an optional integrated diesel, and owners of an installed UBT+ fleet buying service or spares. New data center buyers are now steered toward the UB-V Series, which is where Piller has put its data center marketing.

Role in the data center

Facility-scale rotary UPS from a single 150 kW machine to a 50 MW installation, often paired with gensets in a DeRUPS or isolated parallel architecture.

Key specifications

Technical summary

Series range: 150 kW to 50 MW (UNIBLOCK series); UBTD+ diesel rotary 500 kW to 40 MW Energy storage: batteries or POWERBRIDGE flywheel, specified per project Cooling: air or chilled water; containerized options available Voltage: low and medium voltage applications Efficiency: real efficiencies at 97% stated for the 2008-2014 UBT+ and UBTD+ range Architecture: mechanically coupled rotary hybrid; UB-V successor is electrically coupled Successor rating: UB-V Series at 1,100 kVA (1.0 MW) to 3,600 kVA (3.24 MW) Successor efficiency: up to 98% at full load and 97% at half load Successor service interval: extendable to once every five years with condition monitoring Service-supported life: preventative maintenance to extend system life to at least 20 years

Pricing and availability

Trend: up Warranty, used: 1-year typical from refurbishment dealers.

Lifecycle and maintenance

Flywheel and rotary systems are built around a 20-year design life with no stored-energy replacement, which is the whole economic case against batteries: Active Power markets CleanSource as 20+ years with no battery changes and VYCON rates the VDC above 20 years with runtime that does not degrade. The consumables move to bearings, vacuum and capacitors instead, at a ceramic bearing cartridge every third year on CleanSource HD, annual vacuum-pump oil with an 8-10 year pump on the VDC, and DC capacitors at 7-8 years. Piller extends rotary service intervals to 5 years with condition monitoring. Service history, not calendar age, sets the value of a used rotary asset.

Common failure points

• Bearings — Ceramic ball bearings wear on a fixed interval and a missed change ends the machine
• Vacuum integrity — Lost vacuum raises windage losses and the published runtime no longer holds
• DC capacitors — Aged DC capacitors degrade the converter and the energy it can deliver
• Bearing controller electronics — Active magnetic bearing controllers are proprietary and not field-substitutable
• Generator dependency — Ride-through is 15-60 seconds, so a slow or unproven genset leaves the load exposed
• Lubrication systems — Auto-greased bearing sets run dry when a decommissioned unit sits unserviced

Inspection checklist

Bearing type — establish it first; CleanSource HD runs ceramic ball bearings, the VYCON VDC uses 5-axis levitation Bearing service log — Active Power specifies a cartridge change every 3rd year on HD and every 4th on PLUS MMS Vacuum system — VYCON runs a medical-grade vacuum pump on annual oil service with an 8-10 year pump life DC capacitors — VYCON publishes a 7-8 year replacement point for the VDC's DC capacitors Rotor drop log — the VDC spins 18,500-36,000 rpm and recovers from backup-bearing drops a limited number of times Grease reservoir — Piller POWERBRIDGE auto-greases from a reservoir; an unserviced one voids the 20-year life case Runtime verification — CleanSource HD holds 15 s at 100% load, 29 s at 50% and 56 s at 25% per the UL datasheet Flywheel data — HD spins a steel rotor at 7,700 rpm storing 10.2 MJ; the 6.2 MJ web figure is a page error Efficiency — check against the datasheet: HD is 96.5% at 50% load and up to 98% at full load Generator interface — a flywheel is a bet on the genset; verify start-to-load against a 10-second class requirement Ambient limits — CleanSource HD is rated 32-104 degrees F (0-40 degrees C); verify how the unit was stored Controls and parts — magnetic bearing controllers are proprietary; VYCON ownership has been undisclosed since 2022 Parallel rating — HD parallels up to 7 systems for 4,725 kW; confirm frame count matches the nameplate claim Standards — confirm UL 1778 and cUL CAN/CSA 22.2 No. 107.1; the VDC's UL scope covers 400-600 VDC only Service entitlement — get a written parts letter; Active Power runs a 135,000 sq ft Austin plant with 24/7 service

Procurement channels

Direct from Piller, quoted project by project. Piller maintains stocked parts at service centres worldwide with 24/7 coverage across more than 40 countries, so service and spares are an OEM channel rather than an independent one.

Regional notes

Sold globally from Osterode am Harz, Germany, through Piller subsidiaries. US coverage runs through the same group that owns Active Power in Austin, Texas, since the November 2016 acquisition.