Loading... Please wait...

Delta and Wye Circuit Equations

Typical 3-Phase Wiring Diagrams and Equations for Resistive Heaters 
Definitions 

For Both Wye and Delta 
(Balanced Loads)
 
VP = Phase Voltage  
VL = Line Voltage 
IP = Phase Current 
IL = Line Current 
R = R1 = R2 = R3 = 
Resistance of each branch 
W = Wattage
Wye and Delta Equivalent 
WDELTA = 3 WWYE
 
Open 3-Phase Circuit Formulas: 
Open Delta Watts = 2/3 WDELTA 
Open Wye Watts = 1/2 WWYE 
Open 4-wire Wye Watts = 2/3 WWYE 
3-Phase Wye
(Balanced Load)
 
deltawye1.gif
   3-Phase Open Wye
(No Neutral)
 
deltawye2.gif
IP = I L
VP = VL/1.73
WWYE = VL2 /R = 3 (VP2) /R
WWYE = 1.73VLIL
IPO = I LO
VPO = VL/2
WOWYE = 1/2 ( VL /R)
WOWYE = 2 (VPO2/R)
WOWYE = VLILO
3-Phase Delta
(Balanced Load) 

deltawye3.gif
 3-Phase Open Delta 
deltawye4.gif
IP = I L/1.73
VP = VL
WDELTA = 3(VL2)/R
WDELTA = 1.73VLIL
VP = VL
IPO1 = I PO3 = I LO2
ILO3 = 1.73 I PO1
WODELTA = 2(VL2/R )