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One unused 15/20/25 MVA, 69 kV GrdY to 34.5 kV GrdY power transformer with ABB load tap changer and 12.47 kV buried delta tertiary. Built December 2023 by Pennsylvania Transformer Technology in Raeford, NC. Never energized in service. Oil retested September 2026. Subject to prior sale.



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Overview

New LTC power transformers in this class carry long factory lead times. This one is already built and factory tested.

It is a Pennsylvania Transformer Technology (PTTI) three-phase, 60 Hz, oil-immersed, core-form power transformer rated 15/20/25 MVA ONAN/ONAF/ONAF. It steps 69 kV GrdY down to 34.5 kV GrdY, with an ABB load tap changer on the high-voltage winding and a 12.47 kV buried delta tertiary. The unit was built in December 2023 for an order that did not go to delivery. It has never been energized in service, and per the seller it has stayed at the manufacturer's site in Raeford, North Carolina since it was built.

The insulating oil was sampled and retested in September 2026. Results are below.

Condition: Unused surplus. Manufactured December 2023. Never energized in service (routine factory testing only).

Highlights

  • 15/20/25 MVA ONAN/ONAF/ONAF, 65 °C rise, copper windings
  • 69,000 GrdY/39,837 V to 34,500 GrdY/19,919 V, 60 Hz
  • ABB Type UZE load tap changer on the HV winding, ±10% in 32 steps (33 positions)
  • 12,470 V buried delta tertiary for neutral stabilization (not for external load)
  • 350 kV BIL HV, 200 kV BIL LV
  • 9.03% impedance on 15 MVA base (certified factory test)
  • Sealed tank with automatic nitrogen preservation, inhibited mineral oil, non-PCB per nameplate
  • Made in U.S.A. (Raeford, North Carolina)
  • Oil retested September 2026: 4.5 ppm water, 40.3 kV average breakdown

Specifications

Electrical

ManufacturerPennsylvania Transformer Technology, Inc. (PTTI)
Year builtDecember 2023
TypeThree-phase, oil-immersed, core-form power transformer with LTC and buried delta tertiary
Rating15,000 / 20,000 / 25,000 kVA (ONAN / ONAF / ONAF), 65 °C average winding rise
High voltage69,000 GrdY/39,837 V
Low voltage34,500 GrdY/19,919 V
Tertiary12,470 V buried delta, 5,250 / 7,000 / 8,750 kVA thermal, not brought out for load
ConnectionGrounded wye to grounded wye, H0 and X0 on separate bushings
Frequency60 Hz
Impedance9.03% at 15,000 kVA base, nominal tap (certified factory test)
Load tap changerABB Type UZE RN 200/600 on HV winding, ±10% in 32 steps of 0.625%, 16R to 16L, motor drive with hand crank
HV tap range62,100 V to 75,900 V
Rated current at 25 MVALV 418 A; HV 190 A to 232 A across the tap range
WindingsCopper

Cooling and fluid

CoolingONAN / ONAF / ONAF, 4 detachable radiators, 6 fans with two-stage automatic control
Insulating fluidMineral oil with 0.3% DBPC inhibitor, non-PCB per nameplate
Oil volume3,698 US gal total (main tank 3,292, LTC 154, radiators 252)
Oil preservationSealed tank, automatic nitrogen system, 0.5 to 8.0 psig

Insulation (BIL)

HV (H1 to H3)350 kV, 69 kV class bushings
LV (X1 to X3)200 kV, 34.5 kV class bushings
Tertiary and neutrals (Y1, Y2, H0, X0)110 kV, 15 kV class bushings

Accessories

Bushing CTsMulti-ratio 1200:5 C800 on HV, LV, tertiary and neutrals; 300:5 metering class on HV
Surge arresters3 HV (ABB, 66 kV duty) and 3 LV (Hubbell, 30 kV duty), tank mounted
Protection and gaugesQualitrol pressure relief (main tank and LTC), sudden pressure relay, magnetic oil level gauges, Messko top oil and winding temperature gauges

Oil test, September 24, 2026

Dielectric breakdown (ASTM D1816, 1 mm)40.3 kV average
Water content (Karl Fischer)4.5 ppm
Power factor at 100 °C (ASTM D924)0.31% at 60 Hz

Weights and shipping

Total weight, oil filled102,415 lb (46,454 kg)
Shipping weight91,790 lb (41,635 kg)
Heaviest untanking piece (core and coils)45,400 lb (20,593 kg)
Shipping dimensions (L x D x H)192 x 96 x 162.5 in (4,877 x 2,438 x 4,128 mm)
Overall depth with radiators160 in (4,064 mm)
Shipping notesShips oil filled. Radiators ship detached, make-up oil in totes. No field welding required.

Documentation available

  • Certified factory test report (IEEE C57.12.00 / C57.12.90)
  • Nameplate and outline drawings
  • September 2026 oil test results

Documents are shared with qualified buyers on request.

Location and terms

Located in Raeford, North Carolina, USA. Offered ex works. Transport, rigging, setting, field testing and commissioning are not included unless quoted separately. Pricing on request. CTG sells as principal. Subject to prior sale.

Send us your project details and we will come back with a firm quote within 7 to 14 business days.