Voltage, Current and Power Relations:
In Star Connection
Vph = Phase voltage VL = Line voltage Iph = Phase current IL = Line current
Figure
In star connection
VL = √3 Vph
I L = I ph
P3φ = √3 VL I L cos θ Watts
= 3 V ph I ph cos θ
Where cos θ = Power factor.
In Delta Connection
VL = V ph
I L = √3 I ph
P3φ = 3 VL I L cos θ Watts
= 3 V ph I ph cos θ