What we buy
Ranges we buy on this page
This guide explains dissolved gas analysis, moisture, acidity and furans, and what those oil tests can reveal about transformer windings and paper insulation. It is written for North Carolina plant engineers, utility asset managers, facility directors and contractors reviewing laboratory reports before removing equipment.
A sample from the tank can identify warning signs, but interpretation also needs the nameplate, loading history, sampling date and any record of trips or overheating.
| Phase | kVA | Voltage | Fluid |
|---|---|---|---|
| 1-phase | 10 - 333 kVA | up to 25 kV | Liquid or dry |
| 3-phase | 15 - 20,000 kVA | 34.5 kV | Liquid or dry |
Who we buy from
Six kinds of seller
- Recyclers
- Electrical contractors
- Equipment dealers
- End users
- Demo contractors
- Distributors
Fast offers
A written offer the same business day, based on your photographs.
Dedicated logistics
Our own crew, trailer and crane, not a brokered haul.
No broker fees
One buyer from first call to cleared pad, with nothing skimmed.
How it works
Six steps from photograph to payment
- 01
Take pictures
Photograph the nameplate, the inside of the cabinet and the tank from both ends. Four frames on a phone are enough to price most units.
- 02
Send them to us
Email or text the photographs with the site address and whether the unit is still energised. We reply the same business day with questions or a number.
- 03
Review the offer
The offer names the unit, the site, the price and the pickup window. It is written, dated and good for thirty days unless the unit changes hands.
- 04
We schedule freight
A crew, a trailer and a crane if the pad needs one. You get the date and the arrival window, and the site does not have to close for it.
- 05
Testing on arrival
Winding resistance, insulation resistance and a turns ratio check, plus oil analysis where the unit is liquid-filled. Results travel with the unit.
- 06
Get paid
Payment is released against the signed bill of sale and the scale ticket, by check or ACH, with the paperwork copy left on site.
What we handle
The parts sellers dread
Rigging
Crane, skates and a route survey for anything that will not roll onto a trailer.
Oil containment
Pans, absorbent and a spill plan before a drain plug is touched.
Bill of sale
A document that clears a lien, a lease or a bankruptcy file, not a handwritten note.
PCB paperwork
Testing and manifesting for pre-1979 oil, handled before the unit moves.
On the ground
What it is
Dissolved gas analysis, usually called DGA, measures gases dissolved in transformer insulating oil. Heat and electrical faults break down oil and cellulose into different gases.
A laboratory report lists concentrations, commonly in parts per million, so engineers can evaluate possible arcing, discharge activity or thermal damage.
Other oil tests examine different parts of the insulation system. Moisture testing measures water in the sample; acidity tracks acidic degradation products. Furan analysis measures compounds associated with cellulose breakdown.
Together, these results help assess winding insulation, although none provides a direct inspection of the paper.
Local reality
Why it matters when you sell
When an owner retires a liquid-filled transformer in North Carolina, the latest oil report helps distinguish routine replacement from removal after a fault.
A dated DGA record, paired with relay targets and maintenance notes, gives a buyer more useful evidence than an undocumented statement that the unit worked.
Transformer Buyers NC buys used, surplus, failed and obsolete transformers. For a failed unit, oil results can help explain whether the event involved overheating, internal arcing or deteriorated cellulose.
Keep the laboratory report with the nameplate photograph, outage date and records of oil treatment or replacement.
Around the site
The numbers
Hydrogen can accompany partial discharge and other faults. Methane, ethane and ethylene help characterize thermal activity; acetylene raises concern about high-energy discharge, particularly when it is increasing.
Carbon monoxide and carbon dioxide can indicate cellulose involvement, but gas patterns require interpretation alongside operating history and previous samples.
Moisture is commonly reported in ppm, acidity in milligrams of potassium hydroxide per gram of oil, and furans in ppb or ppm. Check the units before comparing reports.
Oil temperature affects moisture interpretation, while oil replacement or processing can change concentrations without restoring aged winding paper.
Where it sits
Common mistakes
A sample drawn through a dirty valve or exposed to air can distort the laboratory result. Follow the laboratory's sampling instructions, flush the valve as directed and use the specified container.
Record the transformer identification, sampling point, oil temperature and date rather than labeling the bottle only by building.
Another mistake is treating a single gas concentration as a verdict on the windings. Compare samples from the same tank and review the elapsed time, load and oil work between them.
A separate tap-changer compartment can have a different gas pattern; identify its sample clearly.
On the ground
How it affects value
Oil testing affects the technical assessment of a transformer by reducing uncertainty about its condition. Stable gas trends and documented maintenance support a different assessment than rapidly increasing acetylene after a protective trip.
Neither result overrides evidence such as cracked bushings, leaking radiators or a damaged tank.
Elevated furans may indicate aged cellulose, but they do not establish remaining winding life by themselves. Paper type, operating temperature and oil replacement history matter.
Missing reports leave more uncertainty, especially on an older transformer whose service records do not explain previous overheating or repairs to the tank.
Local reality
What to do next
Gather the latest DGA and oil-quality reports, earlier samples, nameplate photographs and maintenance records before planning removal. Include moisture, acidity and furan results if available.
Note whether each sample came from the main tank or tap changer, and identify any filtering, drying or oil replacement between tests.
Do not open a tank or operate a sampling valve on energized equipment without an approved procedure and qualified personnel. Coordinate isolation, grounding and sampling with the responsible electrical team.
Keep oil test interpretation separate from PCB documentation; a DGA report does not establish PCB status.
Get started
Get an offer in minutes
Five fields is all it takes. Photographs help, but a nameplate and a town are enough to start.
No fee, no obligation. We reply the same business day.
Tell us what you have
We reply the same business day.
Questions
Straight answers
Equipment types
Can DGA prove that transformer windings are sound?
No. DGA identifies gases associated with certain fault processes, not the physical condition of every winding turn. A quiet gas pattern cannot rule out all mechanical damage. Engineers may need electrical tests, protection records and inspection findings to assess the windings.
Service area
Does low oil moisture mean the paper is dry?
Not necessarily. Water moves between oil and cellulose as temperature and operating conditions change. A low oil moisture result, especially from a cool transformer, does not directly establish dry winding paper. Record sample temperature and review moisture trends with a qualified specialist.
Payment
Should I keep reports after the oil is replaced?
Yes. Retain reports from before and after oil replacement, along with the treatment date and scope. New oil can lower measured gas and furan concentrations while existing paper damage remains. The earlier reports preserve evidence that a later sample may no longer show.
Logistics
How it affects value: what should a seller know?
Oil testing affects the technical assessment of a transformer by reducing uncertainty about its condition. Stable gas trends and documented maintenance support a different assessment than rapidly increasing acetylene after a protective trip.