Page 28
3.3 External CT
Connection
or Meter with CT
PV
PV
Monitoring
Device
LAN
PV Inverter
Grid Meter
Grid
Backup Loads
Normal Loads
CT
In order for the system to work correctly, a load sensing current transformer MUST be installed. Alternatively,
an external Modbus meter may be used. Meter installation and current transformer installation is described
below.
The current transformer must be connected to the inverter using the supplied 4 way CT/Meter connector.
The White wire (S1+) must be connected to pole 1 of the connector. The Black wire (S2-) must be wired to pole 2.
An RI-D18-CT-16-100 external Modbus meter can be connected to the inverter using the supplied 4 way CT/Meter
connector. The RX(+) must be connected to pole 3 of the connector. The TX(-) must be connected to pole 4.
Only one option may be used.
Current Transformer
External Meter Option
CT/ Meter Wiring Connections:
Pin
Description
Pin
Description
1
CT positive electrode
3
Meter Modbus RX (+)
2
CT negative pole
4
Meter Modbus TX (-)
In both cases, (CT or Meter option), the sensing current transformer must be installed as shown below. The arrow
on the transformer
point towards the incoming utility meter.
must
The inverter must be able to see 100% of the
load or it will not work correctly
