Overview
7
Three-Phase Three-Wire Delta
This is typically seen in manufacturing and industrial environments. There is no neutral wire, just three
power lines with AC waveforms shifted 120° between the successive phases. With this configuration, the
line voltage wires may be connected to the phase A, B and C terminals in any order, so long as the CTs are
connected to matching phases. Three-phase three-wire delta circuits should be measured with the
WNA-3D-240-P or the WNA-3D-480-P.
Phase B
LINE
Phase C
Phase A
LOAD
Current
Transformers
WHITE
BLACK
Source
Faces
WHITE
BLACK
Output
WNA-3D-xxx-P
Continental Control Systems
W
ATT
N
ODE
C CT
B CT
C VAC
B VAC
A VAC
Figure 4: Three-Phase Three-Wire Delta Connection
WARNING
This configuration is dangerous because there is no neutral wire, and as a result the screw
terminals to connect the CTs will have line voltages on them whenever the WattNode is
powered. Therefore, for safety, it is critical that the WattNode is not powered while
connecting the CTs.
