What voltage is typically used for a low voltage source on the primary side of a transformer during testing?

The typical voltage used for a low voltage source on the primary side of a transformer during testing is commonly 120 volts. This voltage level is widely observed in the industry and aligns with standard practices for testing and diagnostic procedures. Using 120 volts is advantageous because it is within the range of standard electrical systems found in residential and commercial applications, making it a safe and practical choice for testing purposes.

In testing transformers, applying a low voltage helps ensure that the device can be safely evaluated without the risks associated with higher voltages. Additionally, 120 volts allows for easier monitoring of the transformer's behavior under operational conditions, including core saturation and efficiency assessments, which are critical aspects of transformer functionality.

Other voltages listed, such as 60 volts, 240 volts, and 480 volts, are either too low or too high for typical low voltage testing practices on transformers, which can complicate the testing process and potentially introduce safety hazards. Therefore, 120 volts is the established norm for such applications.