By switching a distribution system from Delta to Wye, what is the increase in load carrying capacity?

Switching a distribution system from Delta to Wye configuration significantly affects the load carrying capacity due to the different ways voltage and current are distributed in these systems.

In a Delta configuration, the line voltage is equal to the phase voltage, which supports higher currents and, thus, can handle larger loads. However, the Wye configuration introduces a neutral point, and the phase voltage in a Wye system is lower than the line voltage by a factor of the square root of three (approximately 1.732). This means the voltage available to each load is reduced, but the Wye connection allows for a more balanced distribution of load across three phases.

When comparing the two configurations, converting to a Wye system means that the capacity to handle loads effectively increases by approximately 73%. This ratio comes from the relationship between the voltages in the two configurations and the mathematical principles associated with them, specifically the square root of three. By distributing the load through the Wye configuration, the overall system can accommodate higher loads without significantly increasing the stress on the components involved.

Therefore, the increase in load carrying capacity when switching from Delta to Wye is approximately 73%.