A ratio of 1 to 1.73 for a low side voltage rating of a three-phase transformer bank signifies which type of connection?

The ratio of 1 to 1.73 corresponds to the relationship between line voltage and phase voltage in a Wye (Y) connection. In a Wye configuration, the line voltage is √3 times the phase voltage, which leads to the ratio expressing that relation accurately. This is crucial when discussing transformer connections, particularly in three-phase systems.

In a Wye connection, each phase is connected to a common neutral point, allowing for the ability to use both line-to-line and line-to-neutral voltages. The ratio of 1:1.73 illustrates that when you take the line-to-neutral voltage (the phase voltage) and multiply it by the square root of 3, you obtain the line-to-line voltage, which is essential for both calculating voltages in the system and understanding how the transformer operates properly in a three-phase circuit.

The other options represent different configurations that do not produce the same line-to-phase voltage relationship as Wye does. Delta connections, for example, have a different voltage relationship entirely, and Corner Ground and Grounded Delta configurations also possess distinct characteristics that do not align with the 1 to 1.73 ratio. Understanding this ratio is vital for comprehending three-phase transformer configurations and their applications.