01What a 15 MVA Transformer Is Commonly Used For
A 15 MVA transformer is rated for 15,000 kVA. At this capacity, it is usually a three-phase power transformer rather than a small distribution unit. Common categories include substation power transformers, generator step-up (GSU) units, autotransformers and mobile-substation transformers.
In California, these units may serve utility or industrial substations, or connect generation to a utility system. A 15 MVA nameplate does not by itself establish the transformer's application or suitability for another project; voltage, winding configuration, cooling and other specifications must match the intended system. See our information on [substation and power transformers](substation and power transformers) and [generator step-up transformers](generator step-up transformers).
FLAFull-Load Amps for a 15 MVA Transformer
Rated full-load current at common California voltages. Single-phase: amps = kVA × 1000 ÷ volts. Three-phase: amps = kVA × 1000 ÷ (1.732 × volts). Use the nameplate voltage of your unit.
| Phase | Voltage | Full-load amps |
|---|---|---|
| Three-phase | 4.16 kV | 2,082 A |
| Three-phase | 12.47 kV | 694 A |
| Three-phase | 20.78 kV | 417 A |
| Three-phase | 34.5 kV | 251 A |
| Three-phase | 66 kV | 131 A |
| Three-phase | 69 kV | 126 A |
| Three-phase | 115 kV | 75.3 A |
02Which 15 MVA Transformer Designs Are Likely
Most 15 MVA units are assembled three-phase power transformers, although single-phase power units or banks can also occur. Autotransformers and mobile-substation units are other possible configurations; the nameplate and connection diagram are the best way to identify what you have.
A conventional pad-mount or pole-mount transformer is not the typical design at 15 MVA. Standard three-phase pad-mount scope reaches 10 MVA, and standard single-phase pad-mount scope is smaller still. A 15 MVA unit might have a particular enclosure or custom arrangement, but do not classify it from appearance alone. Most units at this rating are station-class equipment; compare [autotransformer configurations](autotransformer configurations) and [mobile substation transformers](mobile substation transformers).
03Voltage Combinations and California Applications
The voltage combination depends on the source, load and network. The full-load amp chart on this page lists three-phase reference values at 4.16, 12.47, 20.78, 34.5, 66, 69 and 115 kV. These are chart voltage points, not a claim that every 15 MVA transformer has any particular pair of windings.
Those voltage levels can be relevant to California industrial and utility systems. For example, PG&E lists 20,780 V and 115 kV configurations, while SCE documents 66 kV subtransmission and 4 kV, 12 kV and 16 kV distribution systems. The actual high- and low-side ratings, taps and grounded-wye or delta connections must be read from the unit's nameplate and diagram.
04How to Read the 15 MVA Full-Load Amps Chart
Use the chart row that matches the transformer's phase and voltage. The page's rendered chart gives full-load amps for three-phase 15 MVA at several voltage points; it does not replace the nameplate, and its values should not be used as a rating for a different voltage or phase.
For a balanced three-phase transformer, full-load current is calculated from apparent power divided by √3 times line-to-line voltage. Current is higher on the lower-voltage winding and lower on the higher-voltage winding. For help comparing capacity and current, see [how transformer kVA and amps relate](how transformer kVA and amps relate).
- Confirm whether the row is three-phase or single-phase.
- Match the chart voltage to the relevant nameplate winding.
- Check all stages if the nameplate lists multiple cooling ratings.
- Use qualified engineering review for operating or protection decisions.
05Physical Size, Weight and Removal Planning
A 15 MVA power transformer is large, heavy equipment, but there is no single reliable dimension or weight for all units. Physical size and shipping weight vary by manufacturer, voltage class, cooling design, accessories and whether radiators, bushings or other components are included.
For an initial review, photograph the overall unit and capture any nameplate fields showing total weight, tank-and-fittings weight, and core-and-coil weight. Site access, clearances, road conditions and lifting requirements can affect removal planning. Do not attempt to move or open the transformer; qualified contractors handle electrical isolation and removal, with utility involvement where applicable.
06What Affects the Value of a Used 15 MVA Transformer
A buyer evaluates the complete specification and condition, not just the 15 MVA rating. Voltage and connection, cooling class, impedance, BIL, tap arrangement, temperature rise and winding material can influence whether the unit fits current demand. Commonly usable California voltage configurations may also affect resale interest.
Age, leaks, corrosion, bushing condition, missing components and available accessories matter. Factory test reports, oil test or DGA records, insulation-resistance results and turns-ratio tests can help establish condition. New-surplus status, quantity and site access also affect an offer. PCB documentation and fluid records are important; rely on testing, records and qualified environmental professionals to determine handling requirements. This is not legal advice. For more context, read [factors that affect used transformer value](factors that affect used transformer value).
07What to Send a 15 MVA Transformer Buyer
To request an offer from California Transformer Buyer, call or text Rocky at (951) 403-5738, or use the contact form. You can also text photos of equipment you are authorized to access, taken from a safe position. California Transformer Buyer reviews equipment located in California only.
Include the quantity, location and condition, along with clear nameplate and overall photos. Useful nameplate details include manufacturer, serial number, year, kVA at each cooling stage, phase, high- and low-side voltage, taps, impedance, BIL, cooling class, fluid type and weight. Send any test reports, PCB or fluid records, and information about site access. The review costs nothing and carries no obligation; the written offer states what is included, who handles rigging and freight, and payment terms before pickup.
- Nameplate and connection-diagram photos
- Overall views and visible condition
- Quantity and California location
- Test reports and environmental records, if available
- Known access or removal constraints
kVANearby Transformer Sizes We Buy
FAQ15 MVA Transformer FAQ
Can I sell a 15 MVA transformer that is still installed?
Yes, you can request an offer while the unit remains installed, provided you own it or have authority to sell it. Send photos from a safe position and share the location, access conditions and whether the transformer is operating, spare or decommissioned. Do not disconnect, de-energize or move it yourself; the owner's qualified electrical contractor or serving utility handles electrical work.
Will you buy a 15 MVA transformer without test reports?
You can still submit its details if test records are unavailable. Share the nameplate, overall condition and any known service or maintenance information, and be clear about what has not been tested. Rocky may ask follow-up questions or request available records. Testing and documentation can help a buyer assess condition, but an offer depends on the unit and the information available.
Is a 15 MVA unit the same as a 15,000 kVA transformer?
Yes. One MVA equals 1,000 kVA, so 15 MVA is 15,000 kVA. Check the nameplate for the rated capacity and whether more than one rating is shown for different cooling stages. A multi-stage rating can indicate different capacities under different cooling conditions, so sending a complete nameplate photo is more useful than reporting only the largest number.
Do you buy a failed or leaking 15 MVA transformer?
California Transformer Buyer reviews equipment in a range of conditions, including failed or leaking units, but cannot promise to purchase every transformer. Describe visible issues and provide any known test or fluid records. Do not open the tank, drain fluid or take samples yourself. Qualified electrical and environmental professionals should determine safe handling and the appropriate path for the equipment and its contents.
Can a 15 MVA transformer be shipped as one piece?
Whether a unit ships assembled or with some components removed depends on its design, weight, dimensions and transport route. Large power transformers can require specialized planning, and state or local road approvals may apply to oversize or overweight loads. Share available weight information and site details so logistics can be considered. Do not arrange or attempt to move the equipment before written terms are agreed.
Can I sell a utility-owned transformer on my property?
Only the owner or someone authorized by the owner can sell the transformer. Equipment located on private property may still belong to a utility or another party, so confirm ownership before requesting an offer. If a utility owns the unit, the property owner cannot sell it. Include any ownership or project documentation that helps establish your authority to transfer it.