Delta and Wye Circuit Equations Notes

Delta and Wye Circuit Equations Notes

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

ForBoth 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
Wyeand Delta Equivalent
WDELTA = 3 WWYE

Open3-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)

3-Phase Wye
 3-Phase Open Wye
(No Neutral)

3-Phase Open Wye
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) 

3-Phase Delta
 3-Phase Open Delta 
3-Phase Open Delta
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 )

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