A 45 kVA three-phase transformer often serves commercial lighting panels, retail suites or smaller HVAC loads. A tenant renovation, service upgrade or equipment change can leave a usable transformer without a job. We buy these units as used equipment and also buy unused surplus left over from projects.
At this rating, enclosed dry-type units and three-phase pad-mount units serve different installation needs. The enclosure alone does not tell us the voltage configuration or condition. Our broader transformer size guide helps separate the kVA rating from other nameplate information when you have several units to identify.
01What the 45 kVA rating actually means
A three-phase transformer's 45 kVA rating describes its total rated apparent power across all three phases. It does not mean 45 kVA per phase, and it is not automatically the same as 45 kW. Real power depends on the connected load's power factor.
The same 45 kVA rating produces different full-load currents at different voltages. For a three-phase example at 480 volts, current equals kVA × 1,000 ÷ (√3 × line-to-line volts): 45 × 1,000 ÷ (√3 × 480) is approximately 54.1 amps. Use the amp table on this page to compare other listed voltages.
Those figures describe rated transformer current, not a complete circuit design. They do not establish breaker selection, conductor sizing or allowable loading for a particular installation. For more context on the calculation, see the kVA and full-load amps guide. We buy the transformer based on its documented rating and configuration, not an estimate from the panel it once supplied.
02Voltage combinations we look for at 45 kVA
A familiar commercial dry-type configuration is a 480-volt primary with a 208Y/120-volt secondary. That arrangement can supply three-phase equipment at 208 volts and line-to-neutral loads at 120 volts. Other 45 kVA configurations exist, so a seller should copy the actual nameplate voltages rather than describe the unit simply as a lighting transformer.
Three-phase pad-mount units can have medium-voltage primaries, such as 12470GrdY/7200, and low-voltage secondaries such as 208Y/120 or 480Y/277. Availability varies by the unit's original application. We pay attention to the complete primary designation, secondary voltage, connection diagram and tap positions because those details affect where the transformer can be reused.
A 480Y/277 secondary may serve 277-volt lighting alongside suitable 480-volt equipment. Retail suites and small HVAC systems do not all use the same voltage, even when their transformers share a kVA rating. Our dry-type transformer buying page covers enclosed dry units, while the nameplate remains the best starting point for identifying yours.
Full-load amps for a 45 kVA 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 | 125 |
| 240 V | 108 |
| 480 V | 54.1 |
| 600 V | 43.3 |
| 2,400 V | 10.8 |
| 4,160 V | 6.2 |
| 12,470 V | 2.1 |
| 13,200 V | 2 |
| 13,800 V | 1.9 |
| 23,000 V | 1.1 |
| 34,500 V | 0.8 |
03Confirm 45 kVA on the nameplate, not the enclosure
Look for a field marked kVA and confirm that it reads 45. Also check that the phase field identifies a three-phase unit. A cabinet's dimensions, a nearby panel label or a handwritten inventory tag cannot reliably establish the rating.
Photograph the whole nameplate straight on, with enough detail to read the manufacturer, serial number, frequency, primary and secondary voltages, impedance and connection diagram. For dry-type equipment, temperature rise and insulation information are useful. For liquid-filled units, include fluid type, fluid quantity and any cooling designation shown on the plate.
A model number containing “45” is not a substitute for the rating field. If a building has several similar cabinets, match each nameplate photo to an overall photo of that unit. A confirmed 30 kVA unit belongs with our 30 kVA transformer information, rather than being grouped into a 45 kVA lot.
04Physical size, weight and access matter
There is no single set of dimensions or weight for every 45 kVA transformer. Dry-type construction, winding material, enclosure style and temperature-rise design can change the package. A pad-mount unit includes a tank and compartment arrangement that creates different handling requirements.
Send dimensions and the nameplate weight when available. Show the base, mounting points and surrounding space in your photos. A unit on an open warehouse floor presents a different pickup situation from one mounted above a ceiling, behind a narrow doorway or inside an occupied electrical room.
For three-phase pad-mount transformers, photograph the exterior, base and visible condition without opening energized compartments. Tell us about leaks, corrosion or damaged doors. We do not perform electrical disconnect work or ask sellers to drain fluid; sellers use their own qualified electricians to de-energize and disconnect equipment.
05What affects buyer interest in a 45 kVA unit
The 45 kVA size fits practical commercial applications, which makes the exact voltage combination important to reuse. A common building voltage can give a unit more potential applications than an unusual configuration. That does not make every 45 kVA transformer interchangeable or guarantee an offer.
We buy all brands and pay attention to completeness and condition. Intact terminals, readable identification, an undamaged enclosure and a clear operating history help us understand the equipment. New-surplus units should be identified as unused, with storage conditions noted; used units should include any known service problems.
If you want to sell 45 kVA transformer equipment after an upgrade, explain why it was removed. A unit replaced only because the load increased is different from one removed after overheating or a fault. Failed or damaged units are reviewed case by case, and useful test records should be included if already available.
06Send the details needed for a written offer
To sell 45 kVA transformer equipment, send a clear nameplate photo, overall photos, location, quantity and condition notes. We review the information and may ask about PCB status, existing test data or site access. If the equipment fits, our written offer spells out price, freight, loading and payment terms; pickup is scheduled with you, and payment follows those terms. See how the selling process works for details.
For liquid-filled equipment, PCB status must be disclosed and documented. Include available fluid labels and records, and identify any known leak or fluid replacement. Do not assume that the unit's age or appearance establishes its PCB status.
Include terminal or connection photos only when they can be obtained safely from de-energized equipment. Existing test reports are helpful, but they do not replace identification photos. Request an offer for your 45 kVA unit with the information you have, and clearly flag anything unknown.
Frequently asked questions
Can I sell a 45 kVA transformer removed from a retail suite?
Yes, Virginia Transformer Buyers buys used 45 kVA three-phase transformers removed from retail suites. Include the primary and secondary voltages and explain whether the unit was working when removed. Note if a tenant renovation, increased load or equipment failure caused the removal, since those are materially different condition histories.
Is a 45 kVA three-phase transformer rated 45 kVA on each phase?
No, the 45 kVA nameplate rating is the total three-phase apparent-power rating, not a separate 45 kVA rating for each phase. Confirm the phase designation and voltage fields on the plate. The amp table on this page helps relate that total rating to full-load current at the listed voltages.
Can you buy a 45 kVA transformer with a missing nameplate?
A missing nameplate makes a 45 kVA transformer harder to identify, so an offer is not assured. Send overall photos, any remaining labels and existing manufacturer documentation tied to that specific unit. Do not assign a rating based only on cabinet size or the breaker that previously supplied it.
Should I clean or drain a 45 kVA pad-mount before selling it?
Do not drain fluid to prepare a 45 kVA pad-mount transformer for sale; Virginia Transformer Buyers does not ask sellers to do that. Send photos showing its current condition and disclose leaks or damage. PCB status must be disclosed and documented, and your qualified electrician handles de-energizing and disconnecting the unit.
Do you buy unused 45 kVA transformers without their original packaging?
Yes, we buy new-surplus 45 kVA transformers, including units without original packaging. Tell us whether the transformer has ever been energized and how it has been stored. Photograph the enclosure, terminals where safely accessible, and nameplate, and disclose missing parts, moisture exposure or handling damage rather than describing condition from packaging alone.