10
3.5.2 Connect RS-485
X
C
B+
A-
W
ATT
N
ODE
W
ATT
N
ODE
A- B+ C
RS-485
X
C
B+
A-
●
RS-485 wiring can be complex when multiple devices are connected, when running wires for
long distances, and when using termination and biasing resistors. If you have any questions,
consult the
●
Be sure to connect the
A-
,
B+
, and
C
(common) terminals. The
X
terminal is normally not used.
You may use the cable shield (if present) for the
C
connection.
●
For long distances, use shielded twisted-pair cable to prevent interference. With shielded
cable, connect the shield to earth ground at one end.
●
RS-485 wiring is daisy-chained between meters, with up to 64 devices per subnet.
3.6 Connect Thermistor
If you ordered your meter with
Option TM1
for use with an external thermistor for temperature
monitoring, you may connect the thermistor as shown below. See
for details
on the required thermistor. Thermistor leads are not polarized, so either lead by by connected to
either of the
C
and
X
screw terminals.
X
C
B+
A-
W
ATT
N
ODE
Thermistor
4 Operation
4.1 Initial Configuration
Generally, the network integrator will remotely configure the WattNode meter and the variables.
For details on configuring the WattNode meter, see the appropriate
for your model.
The meter does not include a display or buttons, so it is not possible to configure or monitor the
meter directly, other than the basic LED diagnostics described below.
At a minimum, the
CtAmps
must be programmed with the rated amps of the attached current
transformers for correct measurements.
4.2 Power Status LEDs
The three status LEDs on the front of the meter can help indicate correct measurements and op-
eration. The “
A
”, “
B
”, and “
C
” on the diagrams indicate the three phases.
4.2.1 Normal Startup
The meter displays the following startup sequence whenever power is first applied.
