GE Grid Solutions Multilin 9450 - Page 12

1–4 EPM 9450/9650 ADVANCED POWER QUALITY METERING SYSTEM – INSTRUCTION MANUAL
DELTA CONNECTION CHAPTER 1: THREE-PHASE POWER MEASUREMENT
Figure 1-4: Phasor Diagram, Three-Phase Voltages and Currents, Delta-Connected
Another common delta connection is the four-wire, grounded delta used for lighting
loads. In this connection the center point of one winding is grounded. On a 120/240
volt, four-wire, grounded delta service the phase-to-ground voltage would be 120
volts on two phases and 208 volts on the third phase. Figure 1.5 shows the phasor
diagram for the voltages in a three-phase, four-wire delta system.
Figure 1-5: Phasor Diagram Showing Three-phase Four-Wire Delta-Connected System

I
A
V
CA
V
AB
V
BC
I
C
I
B
V
A
V
C
V
B
V
CA
V
AB
N V
BC