HOLT Electricians Practice Exam

A transformer rated 25 kVA and larger must have a nameplate showing which of the following?

1. Manufacturer's name and rated kVA

2. Frequency and impedance of the transformer

3. Primary and secondary voltage

4. All of the above

The correct answer is: All of the above

A transformer rated at 25 kVA or larger is required to have a nameplate that displays essential information, which is crucial for safe and proper operation. The nameplate serves as a comprehensive guide for users and installers about the transformer's specifications and operational limits. Having the manufacturer's name and rated kVA is essential as it provides information about the producer of the transformer and the capacity it is designed to handle. This helps ensure that the transformer is appropriate for the intended application. The frequency and impedance specifications are also critical. The frequency indicates the rate at which the transformer is designed to operate, which directly affects its performance and compatibility with the power system. Impedance is vital for understanding how the transformer will behave under load, especially regarding voltage drop and fault current levels. Lastly, including both primary and secondary voltage is important. This information allows users to understand the voltage levels the transformer is designed to work with, ensuring that it matches the source and load requirements effectively. In summary, all of these elements—manufacturer's name and rated kVA, frequency and impedance, and primary and secondary voltage—are crucial for the safe and correct operation of a transformer of this size, which is why a transformer of 25 kVA or larger must exhibit all of the listed