Trafo Power Solutions TMC cast-resin dry-type

Trafo Power Solutions TMC cast-resin dry-type transformers to 25 MVA and 52 kV.

Trafo Power Solutions TMC cast-resin dry-type is one of 32 data center transformers tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.

Trafo Power Solutions dossier: TMC cast-resin dry-types 50 kVA-25 MVA at 52 kV, IP68 and water-cooled options, SafePower name correction, inspection.

Why it matters

Correcting phantom product names protects catalog credibility, and this one replaces a nonexistent brand with a documented 25 MVA / 52 kV cast-resin capability. The line also demonstrates where dry-type engineering is heading: water-cooled AFWF builds, 30,000 A secondaries, and IP68 enclosures extend oil-free transformation into duties US buyers still default to liquid units for.

Who buys it

African mines, industrial plants, and renewable projects specify Trafo/TMC units for fire-critical, IP-rated, and hazardous-area installations; multi-pulse drive duty is the signature use. US relevance is comparative: TMC's 52 kV cast-resin capability matches GEAFOL's ceiling and exceeds most US dry-type lines.

Role in the data center

Reference point for high-capability cast-resin engineering (52 kV, water-cooled, high-current) rather than a US procurement channel today.

Key specifications

Technical summary

Range: 50 kVA-25 MVA Voltage: up to 52 kV primary or secondary Construction: cast resin or VPI Enclosures: IP21-IP68 Standard: IEC 60076-11; classes E3, C3, F1 Cooling: AN, AF, AN/AF, AFAF (closed circuit), AFAW/WF (water) Drive duty: 12- / 18- / 36-pulse multi-winding designs Extreme spec: secondary currents to 30,000 A Markets: African mining, manufacturing, renewables, infrastructure Model: engineered by Trafo, manufactured and tested by TMC (Italy)

Pricing and availability

Comparable secondary-market band: 2595–9495 $ per unit. Trend: up Lead time, new: Engineered to order via TMC Italy; no published lead times. Lead time, used or refurbished: No used channel observed. 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.

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 Connections — torque-check HV and LV terminations; thermal-scan at first energization and re-check within 12 months Clearances — verify electrical clearances and enclosure IP rating match the installation environment Class verification — confirm fire/environmental/climatic classes (F1, E2/E3, C2/C3) against nameplate Harmonic suitability — verify K-factor rating (K-4/K-13) against the intended non-linear load profile Core and frame — inspect for shipping damage and loose core bolts; verify single core ground Energization test — verify secondary voltage within 5% on all phases and no abnormal sound level Records — factory test certificate, PD test data, and service history; missing PD data reprices the unit

Procurement channels

Trafo Power Solutions (Africa) engineering and supply; TMC Transformers direct elsewhere. No used Trafo/TMC units observed; small dry-type class comps trade on Surplus Record (Hammond step-ups at 2,595-9,495 USD new).