Three Phase Electrical Power Transformer - Material: Mild Steel

Key specifications for a three-phase electrical power transformer include its power rating (kVA or MVA), voltage ratings (high and low voltage sides), frequency (typically 50 or 60 Hz), and winding connections (e.g., Delta/Star or Dyn11). Other important specifications are the cooling method (oil or dry type), insulation class, ambient temperature, and applicable standards like IEC or IS.
Core specifications
Power Rating: Specified in kVA or MVA (e.g., 2500 kVA, 5 MVA).
Voltage Ratings: Input (high voltage) and output (low voltage) levels, such as 33 kV and 11 kV or 11/0.433 kV.
Frequency: The operating frequency, commonly 50 Hz or 60 Hz.
Winding Connections: The configuration of the primary and secondary windings, such as Delta (D) and Star (Y). A common notation is "Dyn11," which indicates a primary Delta, secondary Star, and a 30-degree phase shift with a specific phase sequence.
Physical and environmental specifications
Cooling Method: How the transformer dissipates heat, such as oil-natural air-natural (ONAN) for outdoor, oil-immersed transformers, or air-cooled for dry-type transformers.
Installation Type: Where the transformer is located, such as indoor or outdoor.
Insulation Class: The thermal class of the insulation system, such as Class F or H.
Ambient Temperature: The maximum expected ambient temperature where the transformer will operate, often around 40C or 50C.
Efficiency: Typically high, ranging from 90% to 99% depending on the capacity.
Winding Material: The material used for the windings, commonly copper or aluminum.