17-7
IM DL850E-01EN
• Three-Phase Four-Wire (3P4W)
Six channels that receive three pairs of voltage and current signals can be wired.
SOURCE
LOAD
H
L
H
L
H
L
H
L
H
L
H
L
R
S
T
N
I1
I2
I3
U1
U2
U3
H
S
R
T
N
L
CH1
U1
I1
H
L
CH2
H
L
CH3
U2
I2
H
L
CH4
H
L
CH5
U3
I3
H
L
CH6
LORD
SOURCE
Clamp sensor
Clamp sensor
Clamp sensor
• Conversion of Three-Phase Three-Wire System Data to the Three-Voltage Three-Current Measurement
Method (3P3W→3V3A)
Four channels that receive two pairs of voltage and current signals can be wired. Urs and It can be
determined using delta math.
H
L
H
H
L
H
L
L
R
S
T
N
I1
I2
U2
U1
Urs
It
• Delta-Star Transformation (3V3A→3P4W)
Six channels that receive three pairs of voltage and current signals can be wired. Ur, Us, Ut, and In can be
determined using delta math.
The center of the delta connection is assumed to be the center of the star connection. If the actual centers are
not aligned, errors will result in the calculation.
R
S
T
N
I1
I2
I3
U3
U2
U1
Ur
Ut
Us
In
H
L
H
H
L
H
L
H
L
L
H
L
• Star-Delta Transformation (3P4W→3V3A)
Six channels that receive three pairs of voltage and current signals can be wired. Urs, Ust, Utr, and In can be
determined using delta math.
R
S
T
N
I1
I2
I3
U1
U2
U3
Urs
Utr
Ust
In
H
L
H
H
L
H
L
H
L
L
H
L
17 Power Math