What is the formula for three phase power?

The formula for three-phase power is derived from the combination of voltage and current in a three-phase electrical system, where power calculations typically consider the root mean square (RMS) values due to the nature of alternating current. The correct formula, P = V * I * √3, incorporates the factors that account for the phase relationship between the three wires in the system.

In a three-phase system, power is not simply a direct multiplication of voltage and current because of the phase differences between the three currents. The factor of √3 comes into play because it represents the square root of three, which arises from the geometry of three-phase systems and the way the voltages and currents interact.

This formula is essential for calculating the total power delivered in three-phase systems, which is crucial for linemen and electricians when planning and designing electrical installations, ensuring the right capacity for transformers and lines.

The other options represent inaccurate relationships for three-phase power. Simply adding voltage and current does not yield power, and the formulas that divide or multiply without considering the phase angle do not accurately reflect the dynamics of three-phase power systems. Thus, understanding the role of each component in the correct formula is vital for real-world applications in electrical engineering and maintenance.