ADE9000 Technical Reference Manual
UG-1098
Rev. 0 | Page 47 of 86
APPLYING THE
TO A 3-WIRE DELTA
SERVICE
For the highest level of performance when measuring a 3-wire
delta service, connect Phase B to ground, as shown in Figure 64.
For this configuration, write VCONSEL[2:0] = 00. Then VB =
VA − VC, and the
calculates the VAC potential in the
BVRMS register. To calculate the current flowing through IB
from the IA and IC measurements, set ICONSEL = 1 so that
IB = −IA − IC.
VBC 220V
VC
90°
0.353V
90°
3
VBA 220V
VA
30°
0.353V
30°
3
VAC 220V
VB
150°
0.353V
150°
3
VCONSEL = 001
VA, VB, VC
VAP
VBP
VCP
VAN
AGND
DGND
VBN
VCN
220V
–120°
220V
120°
PHASE C
PHASE A
PHASE B
220V
0°
15523-
064
Figure 64. 3-Wire Delta, Phase B Connected to Ground
Note that for this 3-wire delta, Phase B connected to ground
configuration, the phasor diagram of the VA, VC, and VB
waveforms inside the
IC, shown in Figure 65, is
shifted compared to the service diagram shown in Figure 57.
CV_PCF
AI_PCF
AV_PCF
CI_PCF
BI_PCF
BV_PCF
VCONSEL = 1
180°
0°
270° LAGGING
90° LAGGING
15523-
065
Figure 65. Phasor Diagram of xV_PCF and xI_PCF Waveforms Inside the IC
with 3-Wire Delta with Phase B as Ground and VCONSEL = 001
To use the same PCB for both 4-wire wye and 3-wire delta
circuits, another option is to wire Phase B to the neutral
terminal of the meter, keeping the same circuit as used in
Figure 62 or Figure 63. Note that VCONSEL[2:0] must be set to
001 if it is desired to obtain the VAC rms value, which is
calculated in the BVRMS register, and to use the correct phase
sequence detection method for the 3-wire delta configuration.
To calculate the current flowing through IB from the IA and IC
measurements, set ICONSEL = 1 so that IB = −IA − IC.
Alternatively, a series impedance can be used on Phase B, as
shown in Figure 66. This configuration can be advantageous if
an isolated power supply is used; however, the readings are
inaccurate in this configuration if the phase voltages are not
balanced. Use VCONSEL[2:0] = 100 with this configuration so
that VA = VA − VB, VB = VA − VC, and VC = VC − VB. To
calculate the current flowing through IB from the IA and IC
measurements, set ICONSEL = 1 so that IB = −IA − IC.
VBC 220V
VC
90°
0.353V
90°
3
VBA 220V
30°
0.353V
30°
3
VAC 220V
VB
150°
0.353V
150°
3
VCONSEL[2:0] = 100
CALCULATED VA, VB, VC
VAP
VBP
VCP
VAN
AGND
DGND
VBN
VCN
220V
–120°
220V
120°
PHASE A
PHASE B
220V
0°
15523-
066
Figure 66. 3-Wire Delta, Series Impedance on Phase B and VCONSEL = 100
The phasor diagram of the VA, VB, and VC waveforms
computed inside the
for the 3-wire delta with series
impedance on Phase B and VCONSEL = 100 matches the one
shown in Figure 65.
Phase sequence error detection is performed with the
expectation that the VC waveform leads VA; see the Phase
Sequence Error Detection section for more information.
