5
Table 1
above lists the WattNode models and common circuit types. In the “Electrical Service
Types” column, when two voltages are listed with a slash between them, they indicate the line-to-
neutral / line-to-line voltages. The “Line-to-Neutral” and “Line-to-Line” columns show the operating
ranges for the WattNode meters. “non-N.A.” refers to non-North American electrical services.
Connect the line voltages to the meter inputs as shown in the following figures for each service
type. See
Figure 1
above for an overview.
2.2.1 Single-Phase Two-Wire with Neutral
This is a common residential and branch circuit connection. You may monitor up to three single-
phase circuits with one meter by also using the
Ø
B
and
Ø
C
inputs.
Ø
B
Ø
C
N
Ø
A
W
ATT
N
ODE
®
Ø
B
CT
Ø
A
CT
Ø
C
CT
L1
Neutral
Earth
2.2.2 Single-Phase Two-Wire No Neutral
This circuit occurs in residential (commonly 120/240 Vac) and some commercial applications.
The meter is powered from the
Ø
A
and
Ø
B
terminals. We recommend connecting the
N
terminal
to ground to provide a clean voltage reference for the measurement circuitry (no current will flow
through this terminal).
Ø
B
Ø
C
N
Ø
A
W
ATT
N
ODE
®
Ø
B
CT
Ø
A
CT
Ø
C
CT
L2
L1
Earth
2.2.3 Single-Phase Three-Wire with Neutral
This is a common North American residential service at 120/240 Vac.
Ø
B
Ø
C
N
Ø
A
W
ATT
N
ODE
®
Ø
B
CT
Ø
A
CT
Ø
C
CT
L2
L1
Neutral
Earth
2.2.4 Three-Phase Three-Wire Delta No Neutral
This is common in commercial and industrial settings. In some cases, the service may be four-wire
wye while the load is three wire (no neutral).
Occasionally, a load will only be connected to two of the three lines (say
L1
and
L2
). For this case,
connect the two active lines to the
Ø
A
and
Ø
B
terminals and connect two CTs for the two lines.
