Which formula represents the line loss in a three-phase system?

The formula that represents the line loss in a three-phase system is grounded in understanding how power and current interact in such systems. The correct choice incorporates the square root of three (1.732), which is critical in three-phase calculations because it relates to the phase relationships between the currents and voltages in a three-phase system.

The components of the formula consist of K, which represents the resistive factor of the conductor, I for the current flowing through the conductor, and L indicating the length of the conductor. The division by Cmils, which stands for circular mils, reflects the cross-sectional area of the conductor which also affects the resistance.

In three-phase systems, impedance and resistive losses are distributed across three conductors, thus necessitating the factor of the square root of three in the formula. This makes the calculation of line loss more accurate for systems using three-phase alternating current, as it takes into account the geometry and phase shift of the currents.

The other provided formulas either misrepresent the relationship between these variables or do not appropriately adjust for the three-phase aspect, lacking the essential square root of three factor that allows for accurate line loss calculations in these types of systems.