User Manual
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4.8 PV string connection
4.8.1 PV side requirements
System layout of units with external DC switch
1) Local standards or codes may require PV systems that fit with an external DC switch on the DC side. The DC switch
must safely disconnect the open-circuit voltage of the PV array, plus a safety reserve of 20%. Install a DC switch to each
PV string to isolate the DC side of the inverter.
2) The DC switch has to be certified by AS 60947.3:2018 and AS/NZS IEC 60947.1:2020 in the Australian and New
Zealand markets. The Max. current of the DC switch matching with the WTS-25-50K inverter is no less than 40A. We
recommend the following electrical connection.
DC Switch
PE
PE
L3
N
To grounding electrode
--
+
++
AC Breaker
DC INPUT AC OUTPUT
L2
L1
Grid
+
++ + +
Danger
:
High voltage may be present in the inverter!
Ensure all cables are voltage-free before performing electrical operations.
Do not connect the DC switch and AC circuit breaker before finishing the electrical connection.
Note
:
For best practice, ensure PV modules of the same model and specifications are connected in each
string.
Warning
:
When the inverter is connected to the battery, the maximum MPPT voltage and operating voltage is
900V.
When the inverter is not connected to the battery, the maximum MPPT voltage and operating voltage is 950V.
Select the appropriate photovoltaic cable
Outside diameter Conductor core section
Cable requirements
Cable stripping length
5.9-8.8 mm 4 mm² 7 mm
