What is the formula for calculating 3-phase AC power per leg?

The formula for calculating 3-phase AC power per leg relies on understanding the relationships between voltage, current, and power factor. The correct answer involves using the properties of a three-phase system, where power is distributed across three conductors or phases.

The formula ( KVA / V \times 1.732 ) works because:

• In a three-phase system, the total apparent power can be calculated by dividing the total KVA by the line-to-line voltage (V).

• The factor ( 1.732 ) (which is the square root of 3) is integral in three-phase calculations, as it converts the line voltage to the phase voltage when dealing with power in a three-phase circuit. This conversion is essential for accurate calculations of current on a per-leg basis, ensuring that all three phases are taken into account.

This reflects the relationship of power in three-phase circuits, where total power involves multiplying the current by the voltage and accounting for the phase difference created by the three phases.

The importance of the other options lies in their applicability to different calculations. The second option, ( V \times I \times PF ), represents single-phase power calculations where power factor is considered, while the third option, ( Watts = V \