A nameplate looks crowded, but four numbers carry most of the weight.
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Scroll sideways to inspect all fields. With a keyboard, focus the diagram and use the arrow keys.
The kVA rating is the continuous apparent power the unit can carry. Divide it by the rated voltage on a side to get the current that side can supply. That is usually the first thing a buyer checks against the load.
The primary and secondary voltages tell you where the unit sits and what it connects. Match these to the system on each side, including the way the windings are connected.
Read the high-voltage rating closely, because it carries two numbers. On this plate, 12470GrdY/7200 describes one 7,200 V winding connected between one phase conductor and the grounded neutral of a 12,470 V grounded-wye system. The number before GrdY is the system’s line-to-line voltage, and the number after the slash is the winding’s own line-to-neutral rating (7,200 × 1.732 ≈ 12,470). So the 12,470 names the system the unit is built for; it does not make the unit three-phase. Utilities also connect the high-voltage windings of three units with this rating in grounded wye, one on each phase, and each plate still reads 12470GrdY/7200, so the rating alone does not tell you whether a unit hangs by itself or as one of three. Either way, each unit is a single-phase transformer with its high-voltage winding on one phase. The neutral end of a 12470GrdY/7200 winding has reduced insulation and must be effectively grounded, so the unit belongs only on an effectively grounded wye system. A rating that puts the winding voltage first, such as 7200/12470Y, describes a winding that can be connected either in wye on a 12,470 V system or between two phases of a 7,200 V delta system.
The impedance, given as a percent, is quieter but important. It sets how far the voltage sags when load is applied and how much current flows during a fault. A lower impedance lets more fault current through, which the protection downstream has to handle. When you compare two units that look alike, the impedance is often where they differ in ways that matter.
This is educational material, not engineering or procurement advice. Confirm any rating against the manufacturer documentation and a licensed professional before you specify equipment.
Supplier capacity and delivery timing also matter when ordering a transformer. Browse the available DistroForge report editions and check each edition’s period, publication date, and summary to see what it covers. Read the source dates and limitations in the report before applying its findings to an order; a dated edition does not replace a current supplier quote.