GE Multilin EPM 2200 Instruction Manual page 6

1–2
A
B
C
The three voltages are separated by 120
unity power factor the currents are also separated by 120
and other conditions can cause the currents to depart from the ideal 120
Three-phase voltages and currents are usually represented with a phasor diagram. A
phasor diagram for the typical connected voltages and currents is shown below.
Vcn
Ib
Vbn
Three-phase Voltage and Current Phasors for Wye Winding
FIGURE 1–2:
The phasor diagram shows the 120° angular separation between the phase voltages. The
phase-to-phase voltage in a balanced three-phase wye system is 1.732 times the phase-
to-neutral voltage. The center point of the wye is tied together and is typically grounded.
CHAPTER 1: THREE-PHASE POWER MEASUREMENT
Ia
Vbn
N
FIGURE 1–1: Three-phase Wye winding
o
electrically. Under balanced load conditions with
Ic
EPM 2200 MULTI-FUNCTION POWER METERING SYSTEM – USER GUIDE
Van
Vcn
o
. However, unbalanced loads
o
separation.
Van
Ia