System Layout Of Units Without Integrated Dc Switch; Start And Stop; Start Inverter; Stop Inverter - Sunways STT-4K User Manual

Insulator ring
Nut
Screw cap Metal plate
Sealing ring

4.6 System Layout of Units without Integrated DC Switch

Local standards or codes may require that PV systems are fitted with an external DC switch on
the DC side. The DC switch must be able to 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. We recommend the following electrical connection:
26
1
Port 1
2
3
1
Port 2
2
3
1
2
Port 3
3
4
5
6
3/6pin connector
Figure 4-22
Figure 4-23
20-25mm
6mm
20-25mm
6mm

5. Start and Stop

5.1 Start Inverter

When starting the inverter, follow these steps:
1) Turn on the AC breaker first.
2) Turn on the DC switch in the bottom. If the PV string voltage higher than the inverter start-up
voltage, the inverter will start.
3) When both AC and DC power supply are normal, the inverter is ready to start. The inverter
will initiate from checking its internal parameters and grid parameters, if it's within the range,
the green light on the left side of the screen begins to flash, and the "Waiting" message will be
displayed on the OLED display.
4) After self-checking completed, the inverter will start generating electricity, the green light
will remain on, and the OLED display will display real-time power information.

5.2 Stop Inverter

When turning off the inverter, please follow the steps below:
1) Turn off the AC breaker first.
2) Wait 30 seconds and then turn the DC switch to the "OFF" position. At this time, there is
remaining power in the inverter capacitor. Wait for 5 minutes until the inverter is completely
de-energized before operating.
3) Disconnect the AC and DC cables.
Inverter
DC Switch
DC INPUT AC OUTPUT
-
+
-
+
PE
To grounding electrode
Figure 4-24
Grid
AC Breaker
L
N
27