12
I1+
I1-
I2+
I2-
I3+
I3-
V1
V2
V3
Vn
A
N
B
C
I1+
I1-
I2+
I2-
I3+
I3-
V1
V2
V3
Vn
A
N
B C
Diagram 5-5: Three-phase three-wire,
Δ
Delta-connection, 3 CT, 2 PT
Diagram 5-6: Three-phase four-wire,
Y-connection, 3 CT, No PT
I1+
I1-
I2+
I2-
I3+
I3-
V1
V2
V3
Vn
A
N
B
C
I1+
I1-
I2+
I2-
I3+
I3-
V1
V2
V3
Vn
A
N
B
C
Diagram 5-7: Three-phase four-wire,
Y-connection, 3 CT, 3 PT
Diagram 5-8: Three-phase four-wire,
Y-connection, 2 CT, 3 PT
■
The following symbols are used in the diagram:
Symbol
Description
Grounding
Current
transformer
Terminal resistor
Potential
or voltage
transformer
Fuse