Installation 19
●
When wiring over long distances, use shielded twisted-pair cable to prevent interference.
The pulse output channels are the collector and emitter of an optoisolator transistor (also called
a photocoupler) controlled by the meter’s pulse stream (see
for
solid-state relay outputs). These outputs may be connected to most data monitoring devices that
expect a contact closure or relay input: data loggers, energy management systems, etc. Most of
these devices provide excitation voltage with internal pull-up resistors. If your device does not, the
following schematic illustrates connecting pull-up resistors on all three optoisolator outputs with a
pull-up voltage of 5 Vdc.
5V
Rpullup
Rpullup
P1
P2
P3
COM
Rpullup
W
ATT
N
ODE
Figure 10: Optoisolator Outputs
The meter can have from one to three pulse output channels. All three output channels share the
common
COM
or ground connection. Each output channel has its own positive output connec-
tion, labeled
P1
,
P2
, and
P3
(tied to the transistor collectors).
Output Assignments
The following table shows the pulse output channel assignments for the standard bidirectional
output model and different options. See
for details about
Option PV
,
and
for details about
Option DPO
.
WattNode Outputs
P1 Output
P2 Output
P3 Output
Standard:
Bidirectional Outputs
Positive real energy
(all phases)
Negative real energy
(all phases)
Not used
Option P3:
Per-Phase Outputs
Phase A positive
real energy
Phase B positive
real energy
Phase C positive
real energy
Option PV:
Photovoltaic
Phases A+B positive
real energy
Phases A+B negative
real energy
Phase C positive
real energy
Option DPO:
Dual Positive Outputs
Positive real energy
(all phases)
Negative real energy
(all phases)
Positive real energy
(all phases)
Table 2: Pulse Output Assignments
Note: we use the terms “positive” and “negative”, but other common terms are “production” and
“consumption”. You can wire the meter so that positive energy corresponds to either production
or consumption, depending on your application.
