Schneider Electric Trihal cast-resin dry-type transformer

Manufacturer: Schneider Electric

Schneider Electric Trihal cast-resin transformers, 160 kVA to 15 MVA at up to 36 kV with F1 fire class

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

Schneider Electric Trihal dossier: cast-resin 160 kVA-15 MVA at 36 kV, F1 fire class, used unit priced at 15,000 EUR, inspection checklist, failure points.

Why it matters

Trihal is one of three cast-resin lines a European or IEC-spec data hall actually gets quoted, alongside GEAFOL and RESIBLOC, and its F1 fire class removes the oil-room engineering an equivalent liquid unit would force. It is also the only one of the three with an open used price on record: a 2013-build unit at 15,000 EUR EXW on Machineseeker, against 6,150-7,700 EUR for late-1980s cast-resin units of similar rating.

Who buys it

Commercial building engineers, data center fit-outs, marine and tunnel projects, and industrial plants in IEC markets specify Trihal; US buyers encounter it in imported package equipment and IEC-spec colocation builds. Used-market buyers are typically cost-driven European industrials, since 60 Hz US-voltage used units are scarce.

Role in the data center

Indoor MV/LV transformation for IEC-market data halls and for imported modular power blocks that arrive with the transformer already fitted. The F1 fire class and dry construction remove the oil containment, sump and fire-separation engineering a liquid unit would require inside the building, which is what puts it on an upper floor or beside a data hall rather than in a yard.

Key specifications

Technical summary

Range: 160 kVA-15 MVA. HV: up to 36 kV. Example 60 Hz unit: 1,500 kVA, 23 kV to 480Y/277. Cooling: AN standard; AF option. Windings: cast-resin HV, pre-impregnated LV; aluminum standard. Classes: F1 fire, E2 environmental, C2 climatic (IEC 60076-11). Enclosures: IP00-IP31 observed. EU compliance: Ecodesign Regulation 548/2014 (Eco-Design SKUs). LV winding: pre-impregnated; HV cast under vacuum. Altitude: below 2,600 m (example SKU).

Major variations

The SKU range splits first on compliance: standard builds against Eco-Design SKUs meeting EU Regulation 548/2014, which carry different loss figures at the same nameplate rating. Enclosure class runs IP00 open-frame through IP31, cooling is AN standard with an AF fan option, and vector groups across live SKUs span Dyn11, Dyn05 and Yyn0. Windings are cast-resin on the high-voltage side and pre-impregnated on the low-voltage side, aluminum as standard. Altitude is a build constraint rather than an option, with the published 60 Hz example SKU rated below 2,600 m.

Configurations and options

The range runs 160 kVA to 15 MVA at up to 36 kV inside the SeT Series. Primary regulation is one or two off-circuit tap switches, more on some special designs, giving plus or minus two steps of 2.5%, changed by moving links equally on all three phases with the unit dead and the tap screws torqued to 20 Nm. Cooling is AN as standard, with fan sets that allow a sustained overload of 30% or 40%. Enclosure is IP00 open-frame or a housing at IP20, IP21 or IP31. Thermal protection is PTC sensors with a 140 deg C alarm and a 150 deg C shutdown threshold, with optional PT100 sets of three or six and a named relay from the MB103, NT935, T154 and Ziehl MSF 220VU families. Windings are cast resin on the high-voltage side and pre-impregnated on the low-voltage side, aluminum as standard. EU Eco-Design units are a separate part-number family, and live SKUs cover Dyn11, Dyn05 and Yyn0 vector groups.

Compatibility and dependencies

The manual is explicit about what indoor installation costs in space and air. IP00 units need enforced clearance to a solid wall by insulation level: 100 mm at 7.2 kV, 150 mm at 12 kV, 200 mm at 17.5 kV, 250 mm at 24 kV and 350 mm at 36 kV, and 300-400 mm to a mesh wall; a housed unit needs at least 200 mm between wall and ventilation grille. Room ventilation has to move 180 m3/h per kW of transformer losses. Service conditions are 40 deg C maximum ambient, minus 25 deg C minimum, 1,000 m altitude and 90% humidity. Low-voltage connection bars run to the top of the unit and are tinned, so copper and aluminum bars can be landed without a bimetallic adapter, at bolting torques of 20 Nm on M8 up to 100 Nm on M14. High-voltage terminals sit on the upper part of the coils, cables normally entering through the base. PTC or PT100 sensors have to match the relay input the switchboard expects.

Pricing and availability

Comparable secondary-market band: 6150–7700 EUR per unit. Trend: rising Electrical Trader's price history, published 2026-04-01, puts power transformer prices up 77% between 2019 and 2026 with a 45-95% spread by model, and attributes about half the move to materials: copper up roughly 70% and grain-oriented electrical steel up 80-100% between 2020 and 2025, together 50-55% of production cost. The same series shows the annual rate easing, from 34.58% in 2022 to 8-10% in 2025 with 3-5% forecast for 2026. Terrapin Construction Group put dry-type lead times at 0-2 MVA at 20-32 weeks on 2026-06-10. Lead time, new: 20-32 weeks (dry-type class). Lead time, used or refurbished: 1-8 weeks (European dealers). Warranty, used: 3-year typical from major US rebuilders.

Lifecycle and maintenance

Cast-resin and VPI dry-type transformers typically serve 25-30+ years with minimal maintenance: periodic cleaning, PD testing on critical units, fan service on AF designs, and torque checks. There is no oil system to sample, so temperature and PD are the condition indicators. Rebuild options are limited compared with liquid units; failed coils are usually replaced rather than repaired, which makes pre-purchase PD and visual inspection decisive for used units.

Thermal and emissions profile

Transformers produce no combustion emissions; the regulatory profile is efficiency and fire class. US low-voltage dry-type units fall under DOE 10 CFR 431 efficiency rules (DOE 2016 levels, amended 2024 with 2029 compliance), and EU-market cast-resin units fall under Ecodesign Regulation 548/2014 Tier 2. Dry-type construction removes oil fire and spill risk entirely, which is why cast-resin units carry IEC 60076-11 fire class F1 and serve indoor and environmentally sensitive sites.

Common failure points

• Partial discharge — PD in resin voids degrading insulation toward failure
• Resin cracking — Cracks from thermal cycling or mechanical shock
• Contamination — Dust and conductive debris enabling surface tracking
• Cooling fans — Failed AF fans derating capacity
• Connections — Loose terminations overheating under load
• Overheating under harmonics — Excess temperature on non-linear loads beyond K-rating

Inspection checklist

Partial discharge: PD test per IEC 60270 practice; readings above 10 pC warrant investigation on cast-resin coils. Resin condition: inspect all coils per IEC 60076-11 practice for cracks and crazing from thermal cycling; any through-crack fails. Insulation resistance: megger HV/LV/ground; polarization index of 2.0 or higher passes. Turns ratio: TTR on all tap positions; deviation beyond 0.5% from nameplate fails. Winding resistance: three-phase balance within 2% between phases. Contamination: inspect for dust and conductive debris between coils; contamination is a leading dry-type failure driver. Cooling fans (AF units): run-test all fans and verify temperature controller setpoints. Temperature sensors: verify RTD or thermocouple channels read within 5 C of a reference at ambient.

Procurement channels

Schneider distribution for new; Machineseeker (2,781 cast-resin listings) and European dealers for used; GES Repair for US price-on-request units. Square D-brand used dry-types trade separately on eBay and GEI Surplus.

Regional notes

Trihal is an IEC product to IEC 60076-11, published in the technical manual against PN-EN 60076-11:2006, with fire class F1, climatic class C2 and environmental class E2 and test results against HD 464 S1. EU-market units ship as Eco-Design part numbers under Regulation 548/2014, whose Tier 2 levels have applied since July 2021 under amendment 2019/1783, and a pre-Tier-2 unit may not be installable in a new European project. A 60 Hz build exists, with a documented 1,500 kVA 23 kV to 480Y/277 example, but the range's home market is IEC and frequency is set at manufacture. Imported dry-type content carries the Section 232 50% tariff from 2025-08-18.