A 20 MVA transformer is substantial three-phase equipment, often connected with utility substations, data center campuses or generation step-up service. At this size, the voltage ratio and cooling designation matter as much as the headline rating. A unit rated 20 MVA with forced cooling is not the same operating proposition as one rated 20 MVA on natural cooling alone.
We buy equipment from sellers throughout Virginia, including transformers removed during substation upgrades, unused project purchases and retired generation equipment. Our power transformer buying page covers the broader equipment category; this page focuses on the nameplate, operating history and handling details that matter for a 20 MVA unit.
01What the 20 MVA rating actually means
Twenty MVA equals 20,000 kVA of apparent power. It describes the transformer's rated capacity under specified operating conditions, not its physical dimensions or a guaranteed amount of usable real power. Real power in megawatts depends on load power factor, while permissible loading also depends on cooling, temperature limits and operating conditions.
Check whether 20 MVA is the base rating or the highest rating in a cooling sequence. A plate showing 12/16/20 MVA identifies different capacity levels associated with its stated cooling stages. For oil-filled equipment, ONAN denotes natural oil and natural air cooling; ONAF adds forced air cooling. Send the full rating sequence rather than describing the unit only by its largest number.
The amp table on this page helps relate capacity to line voltage. For three-phase equipment, full-load current is I = VA ÷ (√3 × line-to-line volts). As one example, 20,000,000 VA ÷ (√3 × 138,000 V) is approximately 83.7 A. Our kVA and full-load amps guide explains the relationship.
02Voltage combinations and service applications
Twenty-MVA units do not have one standard voltage combination. Examples you may encounter include 69 kV to 13.8 kV, 138 kV to 13.8 kV and 34.5 kV to 13.8 kV. Generation step-up units may connect a generator-voltage winding to a higher-voltage system. These are examples, not interchangeable specifications; the actual nameplate controls.
For utility substation service, we pay attention to winding connections, insulation levels and tap-changing equipment. For a data center campus, a 20 MVA transformer may feed medium-voltage distribution rather than deliver 480Y/277 V directly. For generation service, the generator-side voltage and winding arrangement help distinguish the unit from a distribution-oriented transformer.
Include details about a load tap changer or de-energized tap changer, including its range and condition when known. A voltage description alone can leave out important differences in grounding and connections. Our substation transformer page covers equipment used in these installations.
Full-load amps for a 20 MVA three-phase transformer
The amp table on this page uses the standard formula Amps = kVA × 1,000 ÷ (1.732 × line-to-line volts). Match the voltage on your nameplate to read the rated full-load current of each winding.
| Winding voltage | Full-load amps |
|---|---|
| 208 V | 55,514 |
| 240 V | 48,113 |
| 480 V | 24,056 |
| 600 V | 19,245 |
| 2,400 V | 4,811 |
| 4,160 V | 2,776 |
| 12,470 V | 926 |
| 13,200 V | 875 |
| 13,800 V | 837 |
| 23,000 V | 502 |
| 34,500 V | 335 |
03Confirm 20 MVA from the complete nameplate
Photograph the whole nameplate straight on, with enough resolution to read the smaller fields. Look for 20 MVA, 20,000 kVA or a multi-stage rating ending at that capacity. Confirm the three-phase designation and frequency, and capture both winding voltages rather than relying on a site inventory label.
We also need the manufacturer, serial number, cooling class, impedance, winding connections and listed weights. Photograph separate plates for the tap changer and accessories if present. If the equipment lists IEEE C57 standards, preserve those markings in the photo along with temperature-rise and insulation information.
An asset described locally as a '20-meg transformer' may carry a different base rating or have been grouped with other equipment in a project schedule. If the plate shows a different capacity, our transformer size directory helps identify the appropriate category. Do not substitute an estimated capacity for a readable plate.
04Physical size, weight and transport details
There is no reliable universal weight or footprint for a 20 MVA transformer. Voltage class, insulation design, fluid volume, cooling equipment and construction all affect its dimensions and mass. A higher-voltage unit may have significant bushing clearances, while radiators, conservators and attached cabinets can extend beyond the main tank.
Send available drawings showing overall dimensions, shipping dimensions, total weight and transport weight. Note whether radiators, bushings or other components are installed, removed or stored separately. A shipping weight may exclude fluid or accessories, so it should not be treated as the complete operating weight without checking the drawing notes.
Photograph the route from the transformer to the loading area, including gates, overhead obstructions and nearby structures. Tell us whether it remains on a foundation or is already in storage. We do not perform electrical disconnect work or ask sellers to drain fluid; use your qualified electricians to de-energize and disconnect the equipment.
05What affects demand for a 20 MVA transformer
Demand for a particular 20 MVA unit depends on whether its specifications fit another installation. Capacity alone does not establish suitability. Voltage ratio, frequency, impedance, winding arrangement, cooling capability and tap range can narrow or broaden the available applications.
We buy used, new-surplus and decommissioned units of all brands, but we need to understand what accompanies the transformer. Complete radiators, bushings, fans, control cabinets and tap-changing equipment give a clearer picture than a main tank alone. Tell us about missing components, leaks, storage conditions or known operating problems.
Available maintenance records and test reports help explain condition without replacing the nameplate information. Identify mineral oil or FR3 natural ester when documented, and disclose and document PCB status. We are an independent buyer, not affiliated with any manufacturer, including Virginia Transformer Corp of Roanoke.
06What to send for a 20 MVA transformer offer
When you are ready to sell 20 MVA transformer equipment, send clear nameplate and overall photos, its location, quantity and condition notes through the offer form. We review the information and may ask about PCB documentation, test data or site access. If the equipment fits, we send a written offer specifying price, freight, loading and payment terms, then schedule pickup with you; payment follows those terms. See how the buying process works for details.
For this size, include the cooling-stage ratings, accessory inventory, weight information and whether the unit is still connected. If several transformers are available, label each photo set by serial number. Distinguishing installed units from stored spares helps keep the equipment description and handling requirements clear.
Frequently asked questions
Does a 12/16/20 MVA transformer qualify as a 20 MVA unit?
Yes, its highest listed rating is 20 MVA, but the complete cooling sequence must be identified. That capacity depends on the cooling stage and conditions stated on the nameplate. Send photos showing all ratings and tell us whether the fans, controls and other cooling components are present and operational.
Can I sell a 20 MVA generation step-up transformer?
Yes, we buy 20 MVA generation step-up transformers. Send the generator-side and system-side voltages, winding connections, cooling ratings and condition information. Include any available drawings and records identifying the installation. We need the actual nameplate specifications, not just the generator's megawatt rating, to describe the transformer correctly.
Will you buy a 20 MVA transformer with removed radiators?
Yes, we buy 20 MVA transformers with radiators removed, with the equipment's completeness and condition clearly described. Photograph the tank connections and each stored radiator group. Identify missing parts and explain storage conditions. Do not assume that a transport configuration represents everything included with the sale.
Can you review a failed 20 MVA power transformer?
Failed 20 MVA power transformers are reviewed case by case. Describe the failure, known damage and any available diagnostic findings. Include photos of affected bushings, the tank and accessories where safely accessible. PCB status must be disclosed and documented; do not drain fluid or disturb damaged electrical components for photos.
Does a 20 MVA nameplate mean the transformer supplies 20 MW?
No, a 20 MVA nameplate specifies apparent power, not a fixed 20 MW output. Real power depends on power factor, and operating limits still depend on the transformer's ratings and conditions. For a sale, provide the MVA or kVA rating exactly as listed rather than converting it to an assumed megawatt capacity.
Do you need the operating weight or shipping weight?
Send both operating and shipping weights if they are available, with the drawing notes explaining what each includes. A transport configuration may exclude fluid, radiators, bushings or other components. Also provide dimensions and photos showing the present configuration so the written freight and loading terms can reflect the equipment being sold.