What information must be included on the nameplate of a transformer?

What information must be included on the nameplate of a transformer?

• A. Serial Number Only
• B. Manufacturer Name, Rated KVA, Frequency, Primary and Secondary Voltages, and Impedance
• C. Color and Installation Date
• D. Model Number and Age

Answer: (B)

The essential information on a transformer nameplate is the data that identifies its ratings and enables proper use, installation, and protection. The manufacturer name identifies who built the unit and helps with traceability, warranty, and compliance. The rated KVA shows the maximum apparent power the transformer can deliver continuously without overheating, which is crucial for selecting protective devices and ensuring the transformer isn’t overloaded. The operating frequency matters because transformers are designed for a specific system frequency; using the wrong frequency can change impedance, affect voltage regulation, and cause overheating. The primary and secondary voltages specify the exact voltage levels the windings are designed for and indicate how the winding connections relate (for correct wiring and voltage transformation). The impedance, usually given as a percent, reveals the internal resistance seen by the system, which is used in short-circuit calculations, voltage drop estimates, and protective device coordination. While other details like color or installation date aren’t required for operation, and model number or age may appear for records, the items listed are the key data needed to identify, size, and safely apply the transformer.

The essential information on a transformer nameplate is the data that identifies its ratings and enables proper use, installation, and protection. The manufacturer name identifies who built the unit and helps with traceability, warranty, and compliance. The rated KVA shows the maximum apparent power the transformer can deliver continuously without overheating, which is crucial for selecting protective devices and ensuring the transformer isn’t overloaded. The operating frequency matters because transformers are designed for a specific system frequency; using the wrong frequency can change impedance, affect voltage regulation, and cause overheating. The primary and secondary voltages specify the exact voltage levels the windings are designed for and indicate how the winding connections relate (for correct wiring and voltage transformation). The impedance, usually given as a percent, reveals the internal resistance seen by the system, which is used in short-circuit calculations, voltage drop estimates, and protective device coordination. While other details like color or installation date aren’t required for operation, and model number or age may appear for records, the items listed are the key data needed to identify, size, and safely apply the transformer.