Substation and large power transformer supply
J&J supplies substation power transformers for utility, industrial and data-center projects. Compare the listed MVA, high- and low-side voltages, cooling stages, winding connections, condition and evidence with your one-line and controlling specification. Public equipment includes new/unused project units and a separately identified rebuilt ABB 230/13.8 kV lot. Call Tommy with the required rating, quantity, destination and needed-on-site date for current options and written availability.
J&J Transformers LLC · Sugar Land, Texas · Serving projects nationwide
Tommy Marco · tommy@jjtransformers.com
Current transformer listings
Start with the public ratings below. Call or email Tommy for current availability, pricing, photos and the technical package. Each unit needs project-specific engineering review and remains subject to prior sale.
| Transformer | MVA and duty | Windings | Listed quantity | Condition | Equipment location |
|---|---|---|---|---|---|
| ABB / Hitachi · JJ-230-220-1 | 132/176/220 MVA | 230/34.5 kV with 13.8 kV buried-delta tertiary | 1 unit | Brand new, never used and never energized | USA |
| Georgia Transformer · JJ-TX-001 | 180/240/300 MVA; 63/84/105 MVA tertiary | 138/34.5 kV with 12 kV buried-delta tertiary | 1 documented unit | Brand new, never used and never energized; 2020 nameplate reviewed | USA |
| Prolec GE · JJ-TX-002 | 132/176/220 MVA; 46.2/61.6/77 MVA tertiary | 345/34.5 kV with 13.8 kV delta tertiary | 1 documented unit | Brand new, never used and never energized; approval drawings reviewed | USA |
| Georgia Transformer · JJ-TX-003 | 108/144/180 MVA; 37.8/50.4/63 MVA tertiary | 345/34.5 kV with 12 kV buried-delta tertiary | 1 documented unit | Brand new, never used and never energized; factory acceptance tested September 2024 | USA |
| ABB · JJ-ABB-230-13-3 | 40/53.3 MVA at 55 C; 44.8/59.7 MVA at 65 C | 230 kV delta / 13.8 kV grounded wye | 3 represented units | Rebuilt; three ABB 230/13.8 kV transformers. Rebuild scope and included accessories are confirmed with the quotation | USA |
For hyperscale data centers, utilities and EPC teams, J&J reviews high-MVA and high-kV transformer requirements with phased quantities and current equipment records. Include downstream padmounts and dry types from 500 kVA upward, medium-voltage switchgear and breaker schedules when you need a coordinated electrical equipment quote. Large power-transformer delivery is confirmed against the actual unit and release scope.
For a multi-unit order, specify each electrical configuration, accepted condition and delivery phase. Start with the current equipment records, then request the identity, documents, allocation and quote scope for each proposed unit.
J&J Transformers LLC supplies substation transformers for utilities, data centers, industrial plants and EPC projects nationwide. Start with the incoming system voltage, required output bus and continuous MVA. Review new, unused-surplus and pre-owned equipment by its actual records, or send an unlisted requirement to Tommy.
J&J accepts 5–90 MVA substation transformer requirements and publishes individual equipment offers within this range. Tell us whether the requested MVA is the base or forced-cooled rating. Each available candidate retains its actual winding voltages, cooling stages and stated condition; every size in the table is a quote requirement, not a claim of stock at that exact rating.
| Requested capacity | Purchase information |
|---|---|
| 5 MVA substation transformer for sale — request a match | Specify voltage ratio, base/forced-cooled duty, winding connection, taps, footprint and acceptable condition. |
| 7.5 MVA substation transformer for sale — request a match | Specify voltage ratio, base/forced-cooled duty, winding connection, taps, footprint and acceptable condition. |
| 10 MVA substation transformer for sale — request a match | Specify voltage ratio, base/forced-cooled duty, winding connection, taps, footprint and acceptable condition. |
| 12.5 MVA substation transformer for sale — request a match | Specify voltage ratio, base/forced-cooled duty, winding connection, taps, footprint and acceptable condition. |
| 15 MVA substation transformer for sale — request a match | Specify voltage ratio, base/forced-cooled duty, winding connection, taps, footprint and acceptable condition. |
| 20 MVA substation transformer for sale — request a match | Specify continuous load, cooling stages, impedance, utility requirements, protection interfaces and parallel operation. |
| 25 MVA substation transformer for sale — request a match | Specify continuous load, cooling stages, impedance, utility requirements, protection interfaces and parallel operation. |
| 30 MVA substation transformer for sale — request a match | Specify continuous load, cooling stages, impedance, utility requirements, protection interfaces and parallel operation. |
| 40 MVA substation transformer for sale — request a match | Specify continuous load, cooling stages, impedance, utility requirements, protection interfaces and parallel operation. |
| 50 MVA substation transformer for sale — request a match | Specify cooling-stage MVA, winding duty, insulation, grounding, shipping limits, installation scope and required date. |
| 60 MVA substation transformer for sale — request a match | Specify cooling-stage MVA, winding duty, insulation, grounding, shipping limits, installation scope and required date. |
| 75 MVA substation transformer for sale — request a match | Specify cooling-stage MVA, winding duty, insulation, grounding, shipping limits, installation scope and required date. |
| 90 MVA substation transformer for sale — request a match | Specify cooling-stage MVA, winding duty, insulation, grounding, shipping limits, installation scope and required date. |
For a substation power transformer purchase, send the required system-to-load ratio, continuous MVA and utility specification. A collector step-up design requires separate review for step-down duty. Compare new or used substation transformers by winding connection, grounding, taps, impedance and included equipment; an autotransformer is a distinct construction.
Compare power transformers for sale for 69 kV, 115 kV, 138 kV, 230 kV, 345 kV and 500 kV system projects. Review each equipment record's exact winding voltages, MVA, condition and current allocation before requesting a quote.
Current records separate J&J-confirmed availability, dated written offers, newly submitted inventory schedules and 2027 production positions. Stored surplus is not automatically used equipment, and future production is not ready-to-ship stock. Request current allocation, photos, matching records, inspection and complete loading, shipping and warranty terms through J&J.
For a receiving substation, specify the high-side supply and low-side load voltage, required MVA and cooling duty, connections, neutral/grounding, taps, impedance base, insulation and protection. Confirm which winding supplies the load; a tertiary voltage or a step-up rating alone does not establish the required step-down duty.
Put both offers on the same continuous MVA and cooling basis, voltage ratio, frequency, winding connection, impedance base, tap arrangement, insulation levels, losses and accessory scope. Then compare condition evidence, factory/field tests, freight, installation interfaces and release milestones. A lower price on a different winding duty or incomplete scope is not a like-for-like comparison.
A step-down transformer reduces incoming voltage to the level needed by a substation, facility or distribution bus. J&J supplies large substation transformers for utility, EPC, industrial and data-center projects. Compare public MVA and winding voltages, then call or email for availability and the technical package. The ratio alone does not establish a suitable replacement.
J&J Transformers LLC accepts transformer requirements beyond the public inventory. Send the required MVA or kVA, high- and low-side voltages, quantity, project destination and required date to Tommy Marco at 346-276-9540 or tommy@jjtransformers.com. J&J reviews additional equipment options against the requirement; an unlisted configuration is not a claim of stock or a confirmed delivery date. Availability is subject to prior sale and written reconfirmation.
If the specification is incomplete, start with what you know and identify the open items. Do not change a mandatory voltage, winding connection or other engineering requirement simply to match an advertisement. Your project engineer approves technical alternatives; J&J confirms the offered equipment and commercial scope.
For urgent work, distinguish the date equipment must reach the site from the energization date. Inspection, release, preparation, loading and transport need a written plan for the proposed unit. A public listing or a search request alone does not reserve equipment.
| Your requirement | What to send | What the review establishes |
|---|---|---|
| Exact rating or voltage ratio | MVA at the required cooling stages; high, low and tertiary voltages; quantity | Which documented candidates warrant a technical package review |
| Specific OEM or model | Required make/model and whether your purchasing specification permits alternatives | The exact-match requirement versus alternatives your team may evaluate |
| Replacement or outage | Existing nameplate or one-line, fixed interfaces and required-on-site date | Open technical differences, document needs and the proposed release and transport scope |
| New substation or phased project | Controlling specification, quantity per phase and power-on milestones | Separate equipment requirements and delivery milestones for each phase |
A matching voltage ratio is the starting point. Compare the existing transformer and proposed replacement on the same rating basis before reserving equipment. Send the nameplate or one-line by email when available; an initial conversation can begin with MVA, voltages and your required date.
| Compare | What the project team needs to confirm |
|---|---|
| Capacity and cooling | Required MVA at each cooling stage, ambient conditions and operating duty—not only the highest rating. |
| Winding connections | High, low and tertiary voltages; vector group, phase displacement, neutral and grounding requirements. |
| System performance | Impedance with its MVA base, tap range and controls, insulation levels, protection and fault-duty requirements. |
| Installation and schedule | Terminal arrangement, dimensions, accessories, inspection, loading, transport and the needed-on-site date. |
Submit every rating needed by the system studies and physical interfaces. Include base and forced-cooling MVA, HV/LV/tertiary voltages, maximum system voltage, BIL, impedance and basis, LTC/DETC, vector and grounding, losses, cooling, fluid, temperature rise, sound, site conditions, terminals, accessories, tests, transport limits, and schedule.
| Field | Required input | Why it matters |
|---|---|---|
| kVA/MVA | ONAN and each ONAF/OFAF or other cooling-stage rating | Continuous and contingency capacity; auxiliaries and cooling dependence |
| HV/LV/tertiary | Nominal, maximum system and intended operating ranges | Ratio, insulation, taps, protection and interfaces |
| BIL | Each winding/neutral and coordination basis | System insulation and surge coordination |
| Impedance | Percent, MVA, tap and temperature basis plus tolerances | Fault current, voltage regulation, studies and parallel operation |
| Cooling | ONAN/ONAF/OFAF or other; redundancy and control | Nameplate stages are not interchangeable |
| Vector / neutral | Winding connections, phase displacement, grounding and neutral rating | Protection, grounding and system compatibility |
| Taps | LTC/DETC range, steps, controls, bypass and parallel needs | Voltage regulation and operating strategy |
| Standards/tests | Current purchaser and utility requirements; certified reports or new test scope | A category label does not prove compliance |
| Enclosure/site | Outdoor/indoor, ambient, altitude, seismic, sound, terminal and footprint constraints | Physical and thermal suitability |
| Lead time/origin | Need date, destination, country restrictions and required delivery milestone | Schedule and commercial risk |
The engineer or utility determines whether on-load tap changing is required from voltage-regulation, load-flow, contingency, parallel-operation, and interconnection studies. An LTC adds controls, maintenance, failure modes, rating details, and physical scope; a candidate with the wrong tap range or control scheme may not be interchangeable.
Do not apply one standard by page title. IEEE C57.12.36-2026 covers applicable liquid-immersed distribution-substation transformers and supersedes the 2017 edition; larger or higher-voltage power transformers may instead be governed by IEEE C57.12.00, IEEE C57.12.10, IEEE C57.12.90, utility requirements, and the purchaser specification. Verify scope and edition for the actual unit.
Applicable standards, listings, tests, and efficiency requirements are confirmed for each quoted unit; naming a standard is not a certification claim.
Test scope depends on age, condition, transport, records, voltage class, owner risk tolerance, and whether baseline data exists. Request certified factory reports first; then define inspection, fluid and electrical tests that can reveal condition or shipping change without implying that any single test proves remaining life.
The quote should identify the exact OEM, model and serial number or the controlled factory scope. It should also state ratings, condition, location, origin, included accessories, documents, test status, losses, dimensions and weights, transport configuration, price, currency, Incoterm, taxes or tariffs, schedule, inspection or FAT options, warranty provider, payment terms, exclusions, and validity.
Availability is subject to prior sale, technical review, and written confirmation by J&J Transformers LLC.
Review original photos and confirmed equipment details from J&J's completed transformer sales. These historical units have sold; current requirements are reviewed against the equipment offered today.
Estimate the load, review the candidate's condition records, and compare the complete quotation on the same basis. These resources help your project team identify missing information before accepting a transformer offer.
State the continuous MVA and cooling arrangement you need. Compare impedance on the correct winding pair, power base and tap, with its tolerance and test basis. The same voltage ratio or maximum MVA label does not resolve replacement, parallel-operation or site-interface differences.
Compare the offered transformer with the operating unit and the project specification. Keep the winding duty, cooling-stage ratings, technical deviations, inspection scope and delivery responsibilities beside the quoted price.
Request utility or industrial step-down supply with both source and output voltages, the required continuous MVA and the actual operating arrangement. The dedicated step-down hub separates high-voltage substation equipment from padmount and dry-type distribution requirements, links to exact public records and identifies the documents needed to establish fit.
For a substation transformer for sale, define source/output voltage, continuous MVA and project duty before comparing price. A utility step-down transformer, industrial substation transformer and generator-interconnection transformer may require different winding, grounding, tap and protection arrangements even at similar voltage classes.
Written quotes and supporting records control unit-specific ratings, availability, condition, price, and delivery.
J&J Transformers LLC in Sugar Land, Texas supplies substation transformer equipment nationwide. Contact Tommy Marco at 346-276-9540 or tommy@jjtransformers.com with incoming and output voltages, continuous MVA, condition preference, quantity and required date. Review the proposed unit's documents and current written availability before accepting the offer.
Send the existing unit's nameplate, one-line, winding connections, grounding, impedance, taps, cooling ratings and physical interfaces, plus the required date. Identify whether the spare will operate alone or in parallel. The project engineer reviews electrical fit, protection and installation requirements against the candidate's actual records.
For a substation power transformer purchase, send the required system-to-load ratio, continuous MVA and utility specification. A collector step-up design requires separate review for step-down duty. Compare new or used substation transformers by winding connection, grounding, taps, impedance and included equipment; an autotransformer is a distinct construction. Email tommy@jjtransformers.com or call Tommy Marco at 346-276-9540 for the exact equipment record, price and written availability.
J&J Transformers LLC accepts transformer requirements beyond the public inventory. Send the required MVA or kVA, high- and low-side voltages, quantity, project destination and required date to Tommy Marco at 346-276-9540 or tommy@jjtransformers.com. J&J reviews additional equipment options against the requirement; an unlisted configuration is not a claim of stock or a confirmed delivery date. Availability is subject to prior sale and written reconfirmation.
Yes. Review the 138/34.5, 230/34.5 and 345/34.5 kV pages for public candidates, or email another required ratio. The unit's intended duty, connections, impedance, taps and installation interfaces need project-specific review.
Possibly, but the larger rating alone does not establish a fit. Engineering review must address the system requirements, fault levels, impedance basis, protection, installation and operating conditions before accepting a replacement.
State the required connection and grounding arrangement when you email. J&J will screen the documented winding configuration, including any tertiary, for each candidate. A voltage ratio or a general Wye–Wye description alone is insufficient to approve a match.
Call Tommy Marco at 346-276-9540 or email tommy@jjtransformers.com. Specifications, reports, photos and pricing are shared directly after contact, according to the records available for the proposed unit. Availability remains subject to prior sale and written confirmation.
Yes. Send your required kVA or MVA, input and output voltages, quantity, location and need date. J&J checks supply options for utility, commercial and industrial step-down duties. Availability, condition, engineering acceptance and delivery depend on the specific unit offered.
Yes. Send the required transformer MVA, voltages, quantity, one-line, breaker or switchgear scope and needed-on-site date. J&J reviews equipment supply options even when no public lot matches. Engineering, installation and commissioning are separate unless a written agreement includes them.
A GSU is applied to generator export duty; a substation transformer serves network or facility voltage transformation.
Yes when ratings, redundancy, losses, fault duty, protection, grounding, utility and owner requirements match the campus design.
When system and utility studies require on-load regulation. The LTC range, steps, controls and parallel scheme must be specified.
State the required base and every forced-cooling stage and control; common designations may include ONAN, ONAF and OFAF when documented.
It defines connections and phase displacement used for grounding, protection, harmonics and system compatibility.
Only after electrical, mechanical, condition, testing, transport, protection, losses and integration reviews.
Use the purchaser specification and risk review to define factory-record review, routine/design/special test evidence and any new condition tests.
Freight can be evaluated per unit and destination; the quote must state the shipping configuration, Incoterm, permits, unloading and exclusions.
Email tommy@jjtransformers.com with the old nameplate and what you need. Tommy will follow up on the details.
No. A transformer quotation may cover one unit and specified accessories. A substation package must separately define breakers, switchgear, protection, controls, structures, engineering and delivery. Compare written scope rather than treating the term substation as a complete installed offer.
Yes. Send quantity per configuration, winding voltages, continuous MVA, accepted condition and required delivery phase to Tommy. The quotation identifies the actual unit, documents, allocation and included scope for every position. Identical-unit and parallel-operation requirements need explicit review.
