Three-Phase Power Study Guide

Three-phase study questions often require choosing between real power, apparent power, reactive power, voltage, current, and power factor before any arithmetic begins.

For common balanced line-value calculations, real power uses P = √3 × VLL × I × PF and apparent power uses S = √3 × VLL × I.

• Real power is commonly expressed in kW.
• Apparent power is commonly expressed in kVA.
• Reactive power is commonly expressed in kVAR.
• Do not mix phase values with formulas written for line values.
• Keep W/kW and VA/kVA unit conversions explicit.