Three-Phase Calculator (Star/Delta)

Calculates power relationships in three-phase systems, which are more efficient than single-phase for high-power applications. Supports both star (Y) and delta (Δ) configurations. Worked example: star-connected load, 400 V line, 10 A line current, PF 0.85: phase voltage = 400/1.732 = 231 V, P = 1.732 x 400 x 10 x 0.85 = 5.9 kW, Q = 3.66 kVAR. Line and phase quantities trade by root3: in star a 400 V line means 231 V per phase winding, while delta puts the full 400 V across each element - the same load, different currents per connection.

1. 1

   Step 1

   Select the connection type (Star or Delta)

2. 2

   Step 2

   Enter line voltage and line current

3. 3

   Step 3

   Enter the power factor

4. 4

   Step 4

   View active, reactive, and apparent power

• 1

  Star connection: VL = √3 × Vph, IL = Iph

• 2

  Delta connection: VL = Vph, IL = √3 × Iph

• 3

  Three-phase delivers constant power (no pulsation)

• 4

  More efficient transmission than single-phase

• Confusing line and phase values

• Using wrong √3 factor for star vs. delta

• Forgetting power factor in power calculations

• Assuming unbalanced loads follow balanced formulas