By changing a distribution system from delta to wye, what percentage increase in load carrying capacity is achieved?

Changing a distribution system from delta to wye leads to a significant increase in load carrying capacity due to the differences in voltage levels and the way the two configurations manage current.

In a delta connection, the line voltage is equal to the phase voltage, but in a wye connection, the line voltage is greater than the phase voltage by a factor of √3 (approximately 1.732). This difference allows the wye configuration to accommodate greater loads without exceeding current limits.

When switching from delta to wye, the increase in load carrying capacity can be calculated based on the relationship between line voltage and phase voltage, considering that in a wye system, each phase can operate independently and generally more efficiently. This efficiency translates to an increase in capacity by a factor of approximately 1.732, which corresponds to an increase of about 73%.

This significant increase is why the correct answer is associated with a 73% enhancement in load carrying capacity when converting from delta to wye. Understanding these electrical principles and how different connection types affect system performance is crucial for optimizing distribution systems in various applications.