26
27
⑤ Insert the positive and negative cables into the corresponding positive and negative
connectors, pull back the DC cable to ensure that the terminal is tightly attached in the
connector.
⑥ Use an open-end wrench to screw the nut to the end to ensure that the terminal is well
sealed, as shown in Figure 4-13:
3. Insert the positive and negative connectors into the inverter DC input terminals
respectively, a click sound should be heard if the terminals are well connected, as shown
in Figure 4-14:
Figure 4-13
Open-end Wrench
Warning
① Before assembling the DC connector, make sure that the cable polarity is correct.
② Use a multimeter to measure the voltage of the DC input string, verify the polarity of
the DC input cable, and ensure that each string voltage is within 1000V.
4. Seal the unused PV terminals with the terminal caps.
Figure 4-14
COM2-1
COM2-2
COM1
4.4.2 Connection of AC output
Before connecting to the power grid, make sure that the power grid voltage and
frequency meet the requirements of the inverter. See technical parameters for details.
All Sunways inverters incorporate internal RCD (Residual Current Device) to protect
against possible electrocution in case of a malfunction of the PV array, cables or inverter
(DC). The RCD in the Sunways inverter can detect leakage on the DC side. An external RCD
is required in some countries. The installer must check which type of RCD is required by
the specific local electric codes. Installation of an RCD must always be conducted in
accordance with local codes and standards. Sunways recommends the use of a type-A
RCD, with a tripping current of 300mA or higher.
The recommended cable and AC switch for the Sunways STT 4-25kW series three phase
inverter are shown in the following table:
Model
STT-4K STT-5K STT-6K STT-8K STT-10K STT-12K STT-15K STT-17K STT-20K STT-25K
Coper
Cable
2.5-10
mm
2
2.5-10
mm
2
2.5-10
mm
2
4-10
mm
2
4-10
mm
2
4-10
mm
2
6-10
mm
2
8-10
mm
2
8-10
mm
2
8-10
mm
2
Breaker
20A
20A
20A
20A
32A
32A
32A
40A
40A
50A
Figure 4-12
Crimping Plier
4 Installation
4 Installation
