Why the nameplate is the starting point
A transformer's outside dimensions do not identify its electrical design. Two units that look similar can have different ratings, voltages, winding configurations, cooling classes and applications. Buyers use nameplate information to determine whether a unit matches current demand, whether additional technical information is needed and how the equipment should be described.
A missing or unreadable plate does not automatically eliminate a unit, but it increases uncertainty. In that case, photographs, drawings, purchase records, test reports and owner asset records become more important.
Manufacturer, model, serial number and manufacturing date
The manufacturer and model help identify the design family. The serial number distinguishes the specific unit and helps connect it to service records or test reports. The manufacturing date provides context for design, marketability and records, but age alone does not determine whether a transformer is reusable or recyclable.
Photograph these fields clearly. Do not publish or distribute unrelated facility asset numbers if your organization treats them as confidential; provide them directly during a controlled evaluation instead.
kVA or MVA rating
The apparent-power rating describes the transformer's designed capacity. Distribution units commonly display kilovolt-amperes, while larger power transformers may display megavolt-amperes. Buyers compare this rating with voltage, phase, cooling and condition rather than treating it as a stand-alone value.
If multiple ratings are shown, capture the entire table. Ratings may change with cooling stages or temperature rise. Cropping the photograph too tightly can remove the note that explains the numbers.
Primary and secondary voltage
Voltage information is one of the most important market-fit details. Capture all primary and secondary values, taps and connection diagrams. A partial image that shows only one voltage can lead to the wrong conclusion about the unit.
Do not infer voltage from where the transformer was installed. The nameplate, drawings and qualified electrical records are better sources. If the plate is damaged, photograph any additional diagrams or labels on the cabinet.
Phase, frequency, impedance and connection
Single-phase and three-phase equipment serve different applications. Frequency and winding connection also matter. Percent impedance can be important to system design and compatibility. These fields help a technical reviewer determine whether the unit fits a reuse market or should be evaluated primarily for recovery.
A seller does not need to interpret every symbol before submitting a unit. The goal is to provide a legible, complete image so a qualified reviewer can read the original information.
Cooling class, fluid and weight information
Cooling class identifies how the transformer is designed to manage heat. Oil-filled and dry-type units use different notation and construction. Nameplates may also show total weight, core-and-coil weight, fluid weight or fluid volume. These values are useful for logistics but should not replace an actual removal plan.
Fluid references on the plate are part of the record, not a complete determination of current contents or PCB status. Prior retrofill, service or contamination history may require separate documentation. Keep available test reports connected to the serial number.
How to take a useful nameplate photograph
Use indirect daylight or a bright work light that does not create glare. Hold the camera parallel to the plate. Take one full image and several close images if the plate is large. Review the photograph at full size before leaving the equipment; phone screens can hide blur until later.
Include a wider photograph showing the plate on the transformer. For a lot of units, rename each file with the same item number used on the inventory sheet. Never climb, open energized compartments or cross restricted boundaries to obtain a photo.