The nameplate of a transformer is a metal or plastic plate that is affixed to the transformer's body, typically on its exterior. It contains important information about the transformer, which is essential for proper installation, maintenance, and operation. The information on the nameplate may vary depending on the specific type and application of the transformer, but it generally includes the following key details:
Transformer Rating: This includes the rated power capacity of the transformer, often expressed in kilovolt-amperes (kVA) or kilowatts (kW). The rating specifies the maximum amount of power the transformer can handle under normal operating conditions.
Voltage Ratings: The nameplate will indicate the primary and secondary voltage ratings of the transformer. For example, it might list the primary voltage as the voltage it is designed to be connected to on the high-voltage side, and the secondary voltage as the voltage it is designed to deliver on the low-voltage side.
Frequency: The frequency of the alternating current (AC) that the transformer is designed for, usually 50 Hz or 60 Hz.
Impedance or Percentage Impedance: The impedance or percentage impedance is a measure of the transformer's internal resistance to the flow of current. It helps to understand the transformer's ability to withstand fault currents.
Transformer Type: The nameplate will indicate the type of transformer, such as "Distribution Transformer" or "Power Transformer."
Manufacturer Information: This includes the name of the manufacturer or company that produced the transformer.
Serial Number: A unique serial number is usually assigned to each transformer for identification and tracking purposes.
Year of Manufacture: The year when the transformer was manufactured.
Cooling Method: This indicates the cooling system used by the transformer, such as "ONAN" (Oil Natural Air Natural), "ONAF" (Oil Natural Air Forced), "ONAF/ODAF" (Oil Natural Air Forced/Oil Directed Air Forced), etc.
Tapping Range (if applicable): For certain transformers, there might be tapping points on the windings to allow for voltage adjustments. The nameplate will indicate the tapping range and the number of taps.
Efficiency: In some cases, the nameplate may include information about the transformer's efficiency at a specific load.
Standards Compliance: The nameplate might mention the applicable standards and specifications that the transformer complies with, ensuring it meets safety and performance requirements.
It is essential to refer to the nameplate before installing or working with a transformer to ensure it is appropriately used and connected within its rated limits.