Sunways STT Series User manual

SUNWAYS TECHNOLOGIES CO., LTD.
Grid-connected Inverter
STT 4~25KTL
User Manual
EN

CONTENTS
1 Preface ……………………………………………………… 5
1.1 Overview ………………………………………………………………………… 5
1.2 Target Groups …………………………………………………………………… 5
2 Safety Instructions ……………………………………… 6
2.1 Safety Notes ……………………………………………………………………… 6
2.2 Statement ………………………………………………………………………… 6
2.3 Important Safety Matters ……………………………………………………… 7
2.4 Symbols Explanation …………………………………………………………… 8
3 Product Description ……………………………………… 11
3.1 Basic Features ………………………………………………………………… 11
3.2 Physical Layout ……………………………………………………………… 12
3.3 Display Interface ……………………………………………………………… 14
3.4 Packing List …………………………………………………………………… 15
4 Installation ………………………………………………… 18
4.1 Location ………………………………………………………………………… 18
4.2Mounting（standard bracket） ……………………………………………… 20
4.3 Mounting（Including L-shaped plate） …………………………………… 22
4.4 External ground connection ………………………………………………… 25
4.5 Electrical Connection ………………………………………………………… 26
4.6 Monitoring Device Installation ……………………………………………… 33
4.7 CT/RS485/DRED Connection ………………………………………………… 34
5 Start and Stop ……………………………………………… 38
5.1 Start the Inverter ……………………………………………………………… 38
5.2 Stop the Inverter ……………………………………………………………… 38
6 General Operation ………………………………………… 39
6.1 Display Operation …………………………………………………………… 39
6.2 Country Code (Safety Code) Setting ……………………………………… 40
6.3 Auto-Test ……………………………………………………………………… 41
6.4 Power Quality Response Modes …………………………………………… 42
6.5 Online Monitoring APP ……………………………………………………… 42
7 Troubleshooting …………………………………………… 43
7.1 Error Message ………………………………………………………………… 43
7.2 Maintenance …………………………………………………………………… 47
8 Technical Parameters …………………………………… 48

4 5
Attention
The products, services or features purchased are subject to the commercial contracts
and terms of Sunways technologies Co., Ltd. All or part of the products, services or
features described in this document may not be within purchased. Unless otherwise
agreed in the contract, the Company shall not make any express or implied declara-
tion or guarantee of the contents of this document.
Due to product version upgrades or other reasons, the contents of this document will
be updated periodically. Unless otherwise agreed, this document serves only as a
guide to use, and all statements, information and recommendations in this document
do not constitute any express or implied guarantee.
1 Preface
※ 1.1 Overview
This manual is an integral part of Sunways STT 4-25kW series three-phase inverters (here-
inafter referred to as the inverter). It mainly introduces the assembly, installation, electri-
cal connection, maintenance and troubleshooting of the products. Before installing and
using the inverter, please read this manual carefully, understand the safety information
and be familiar with the functions and characteristics of the inverter.
※ 1.2 Target Groups
This manual is applicable to the electrical installers with professional quali󽗉cations and
end-users. If there are any problems in the installation process, please call Sunways ser-
vice telephone at [phone] or email Sunways at [e-mail] for
consultation.
1 PrefaceAttention

6 7
2 Safety Instructions
2 Safety Instructions2 Safety Instructions
※ 2.1 Safety Notes
① Before installation, please read this manual carefully and follow the instructions in this
manual strictly.
② Installers need to undergo professional training or obtain electrical related profession-
al quali󽗉cation certi󽗉cates.
③ When installing, do not open the front cover of the inverter. Apart from performing
work at the wiring terminal (as instructed in this manual), touching or changing compo-
nents without authorization may cause injury to people, damage to inverters and annul-
ment of the warranty.
④ All electrical installations must conform to local electrical safety standards.
⑤ If the inverter needs maintenance, please contact the local designated personnel for
system installation and maintenance.
⑥ To use this grid-connected inverter for power generation needs the permission of the
local power supply authority.
⑦ The temperature of some parts of the inverter may exceed 60° C during operation. To
avoid being burnt do not touch the inverter during operation. Let it cool before touching
it.
⑧ When exposed to sunlight, the PV array generates dangerous high DC voltage. Please
operate according to our instructions, or it will result in danger to life.
※ 2.2 Statement
Sunways Technologies Co.,Ltd. has the right not to undertake quality assurance in any of
the following circumstances:
① Damages caused by improper transportation.
② Damages caused by incorrect storage, installation or use.
③ Damages caused by installation and use of equipment by non-professionals or un-
trained personnel.
④ Damages caused by failure to comply with the instructions and safety warnings in this
document.
⑤ Damages of running in an environment that does not meet the requirements stated in
this document.
⑥ Damages caused by operation beyond the parameters speci󽗉ed in applicable technical
speci󽗉cations.
⑦ Damages caused by unauthorized disassembly, alteration of products or modi󽗉cation
of software codes.
⑧ Damages caused by abnormal natural environment (force majeure, such as lightning,
earthquake, 󽗉re, storm, etc.).
⑨ Any damages caused by the process of installation and operation which don't follow
the local standards and regulations.
⑩ Products beyond the warranty period.
※ 2.3 Important Safety Matters
Danger
Dangerous situation, if not avoided, it could result in death or serious personal injury.
Warning
Potentially dangerous situation, if not avoided, may result in death or serious personal
injury.
Caution
Potentially dangerous situation, if not avoided, may result in moderate or minor person-
al injury.

8 9
※ 2.4 Symbols Explanation
This chapter mainly elaborates the symbols displayed on the inverter, nameplate and
packing box.
Attention
The safety warning information about equipment or environment, to prevent equipment
damage, data loss, equipment performance degradation or other unpredictable results.
Note
Symbol highlights important information, best practices and tips, etc.
2.4.1 Symbols on the Inverter
2.4.2 Symbol on the Inverter nameplate
Inverter status indicator.
Inverter running indicator.
Grounding symbol, the inverter casing needs to be properly grounded.
The inverter cannot be disposed of with household waste.
Please read the instructions carefully before installation.
Do not touch any internal parts of the inverter until 5 min after being disconnected from
the mains and PV input.
CE mark, the inverter complies with the requirements of the applicable CE guidelines.
TUV certi󽗉cation.
SAA certi󽗉cation.
Danger. Risk of electric shock!
2 Safety Instructions2 Safety Instructions

10 11
Figure 3-1 Applicable grid types
The surface is hot during operation and no touch is allowed.
Electric shock hazard, live parts, risk of electric shock, do not touch.
2.4.3 Symbol on the Packing box
Handle with care.
This side up.
Keep dry.
Stacked layers.
3 Product Description
3 Product Description
※ 3.1 Basic Features
3.1.1 Function
The Sunways STT 4-25kW series inverter is a three-phase grid-connected PV inverter which used to
e󽗋ciently convert the DC power generated by the PV string Into AC power and feed it into the grid.
3.1.2 Models
The STT 4-25kW series inverter includes 20 models which are listed below:
STT-4KTL, STT-5KTL, STT-6KTL, STT-8KTL, STT-10KTL, STT-12KTL, STT-15KTL, STT-17KTL, STT-20KTL, STT-25KTL
STT-4KTL-P, STT-5KTL-P, STT-6KTL-P, STT-8KTL-P, STT-10KTL-P, STT-12KTL-P, STT-15KTL-P, STT-17KTL-P,
STT-20KTL-P, STT-25KTL-P
3.1.3 Applicable grid type
The applicable grid types for the Sunways STT 4-25kW series are TN-S, TN-C, TN-C-S, IT and TT. When ap-
plied to the TT grid, the voltage of N to PE should be less than 30V.For more details please see Figure3-1:
2 Safety Instructions
Sunways
STT Series
TN-S
Transformer
Sunways
STT Series
TN-C
Transformer
Sunways
STT Series
TN-C-S
Transformer
Sunways
STT Series
TT
Transformer
Sunways
STT Series
IT
Transformer

12 13
Figure 3-4 Bottom view
3.2.3 Inverter Bottom View
3 Product Description 3 Product Description
Wiring terminals are at the bottom of the inverter, as shown in the table below.
Item Terminal Note
1 DC Input terminal PV connector
2 COM 1 Port WiFi/LAN/GPRS/4G device connector
3 COM 2 Port RS485/DRED connector
4 AC Output Terminal Used for AC output cable connection
3.1.4 Storage conditions
① Inverter must be stored in its original packaging.
② The storage temperature and humidity should be in the range of -30℃ and+ 60℃ , and
less than 90%, respectively.
③ If a batch of inverters needs to be stored, the height of each pile should be no more
than 6 levels.
※ 3.2 Physical Layout
Figure 3-2 Front view
3.2.1 Inverter front view
3.2.2 Inverter side view
Figure 3-3 Side view
Logo
Display
550mm
410mm
410mm
175mm
Name
Plate
175mm
DC Switch (Optional) Com2 Port
(Optional)
DC Input Terminal
Back Rail
Com1 Port
AC Output Terminal
Figure 3-5 Inverter back view
3.2.4 Inverter back view
Back Rail
Vent

14 15
※ 3.3 Display Interface
※ 3.4 Packing List
The package of the inverter includes the following accessories. Please check whether the
accessories in the packing box are complete when receiving the goods. See Figure 3-7 for
the packing list.
Item Indicator Status Description
1Power
Indicator
O󽗈 No input voltage detected or input voltage is too low.
Slow 󽗊ashing Inverter powered on, waiting for the grid connection.
Quick 󽗊ashing Inverter detected grid power and entered self-test status.
On Normal, grid-connected and power generated.
2Alarm
Indicator
On An alarm or faults detected, specific fault information can be
viewed from the display.
O󽗈 The inverter is running normally.
Slow 󽗊ashing The monitoring device is not connected to the router or is not
connected to internet.
Quick 󽗊ashing The monitoring device is connected to the router or connected to
internet but not connected to the server.
sunways
Item Indicator Status Description
3OLED
Display
On Display the inverter operating information.
O󽗈 If the button pressed without any response, the screen is faulty or
not well connected.
4 Button Physical button Switch OLED display information and set parameters by short
press and long press.
Figure 3-6 Display interface Inverter×1 Wall Bracket×1
Expansion Bolt×4 3Pin Terminal×1 ①
3 Product Description 3 Product Description

16 17
3 Product Description
Figure 3-7 Packing list
Inspection
Report
User
Manual
Quick
Guide
User GuidePV Terminal×2 Monitoring Device×1(Optional)
AC Terminal×1 Ground Terminal×1
6Pin Terminal×1
②
3 Product Description
Note
① Export limitation & control version 2pcs; RS485 and DRED version 1 pcs (This connector
already pre-installed inside the inverter).
② STT 4-12kW 2pcs / STT 15kW 3pcs / STT 17-25kW 4pcs.
③ DRED version only (This connector already pre-installed inside the inverter).
④L-shaped plate is optional, select according to needs.
③④
L-shaped Plate(Optional)

18 19
Figure 4-1 Recommended installation location
4 Installation
4 Installation
※ 4.1 Location
The Sunways STT 4-25kW series inverters designed with IP65 protection enclosure for
indoor and outdoor installations. When selecting an inverter installation location, the fol-
lowing factors should be considered:
① The wall on which the inverters mounted must be able to withstand the weight of the
inverter.
② The inverter needs to be installed in a well-ventilated environment.
③ Do not expose the inverter directly to strong sunlight to prevent excessive temperature
operation. The inverter should be installed in a place with shelter to prevent direct expo-
sure to sunlight and rain.
④ Install the inverter at eye level for easy inspection of screen data and further mainte-
nance.
⑤ The ambient temperature of the inverter installation location should be between -30℃
and 60℃ .
⑥ The surface temperature of the inverter may reach up to 75℃ . To avoid risk of burns,
do not touch the inverter while it's operating and inverter must be installed out of reach-
ing of children.
4.1.1 Installation location
Recommended installation location of the inverter, as shown in Figure 4-1:
Warning
Do not put 󽗊ammable and explosive articles around the inverter.
Figure 4-3 Recommended installation angle
4 Installation
4.1.2 Installation Spacing
Figure 4-2 Recommended installation spacing
4.1.3 Installation Angle
The requirements for inverter installation spacing are shown in Figure 4-2:
The installation angle of the inverter is recommended as shown in Figure 4-3:
500mm 500mm
500mm
500mm
300mm
300mm 300mm

20 21
※ 4.2 Mounting（Standard bracket）
① Use the wall bracket as the template to mark the position of 5 holes on the wall. See
Figure 4-5 for details:
Figure 4-5 Marking hole position using installation bracket
Figure 4-4 Dimensions of wall bracket
4.2.1 Wall bracket installation
Dimensions of wall bracket, see Figure 4-4:
150mm
300mm
150mm
150mm150mm
Figure 4-6 Fixing the wall bracket
② Use an electrical driller with 10mm diameter bit to drill 5 holes in the wall with 80mm
depth.
③ Insert the expansion tubes into the holes and tighten them, then 󽗉x the bracket onto
the wall with expansion screws by using a cross screwdriver, as shown in Figure 4-6:
Lift the inverter, hang the back rail on the 󽗉xed wall bracket carefully. See Figure 4-7 for details:
Figure 4-7 Mounting the inverter
Warning
Before drilling, make sure to avoid any buried water tube and electric wires in the wall.
4.2.2 Mounting the inverter
4 Installation 4 Installation

22 23
※ 4.3 Mounting（Including L-shaped plate）
4.3.1 Wall bracket installation
Dimensions of wall bracket, see Figure 4-8:
Figure 4-8 Dimensions of wall bracket
① Use the wall bracket as the template to mark the position of 5 holes on the wall. See
Figure 4-9 for details:
Figure 4-9 Marking hole position using installation bracket
② Bracket assembly
Prepare the two M5 screws and L-shaped plate in the accessory bag, then 󽗉x the L-shaped
plate to the mounting bracket.
Figure 4-10 Bracket assembly
③ Use an electrical driller with 10mm diameter bit to drill 5 holes in the wall with 80mm depth.
Warning
Before drilling, make sure to avoid any buried water tube and electric wires in the wall.
④ Insert the expansion tubes into the holes and tighten them, then 󽗉x the bracket onto
the wall with expansion screws by using a cross screwdriver, as shown in Figure 4-11:
Figure 4-11 Fixing the wall bracket
4 Installation 4 Installation
150mm
300mm
150mm
150mm150mm

24 25
※ 4.4 External ground connection
Ground terminal connection steps:
① The external grounding terminal is located in the lower right side of the inverter.
② Fix the grounding terminal to the PE wire with a proper tool and lock the grounding
terminal to the grounding hole in the lower right side of the inverter, as shown in Figure
4-13.
③ The cross-sectional area of the external grounding cable is 4mm2.
Danger
Do not connect the N-wire as a protective ground wire to the inverter casing. Otherwise,
it may cause electric shock.
Attention
Good grounding is good for resisting surge voltage shock and improving EMI perfor-
mance. Inverters must be well-grounded.
For a system with only one inverter, the PE cable needs to be grounded.
For a multi-inverter system, all inverters PE wires need to be connected to the same
grounding copper bar to ensure equipotential bonding.
Figure 4-13 Grounding terminal connection
4 Installation
Lift the inverter, hang the back rail on the 󽗉xed wall bracket carefully. Screws the inverter to
the L-shaped plate (The lock is purchased separately). See Figure 4-12 for details:
4.3.2 Mounting the inverter
Figure 4-12 Mounting the inverter
4 Installation

26 27
※ 4.5 Electrical Connection
Danger
A high voltage in the conductive part of the inverter may cause an electric shock. When
installing the inverter, make sure that the AC and DC sides of the inverter are completely
de-energized.
Warning
Do not ground the positive or negative pole of the PV string, otherwise it will cause seri-
ous damage to the inverter.
Warning
Static may cause damage to the electronic components of the inverter. Anti- static mea-
sures should be taken during installation and maintenance.
Attention
Do not use other brands or other types of terminals other than the terminals in the ac-
cessory package. Sunways has the right to refuse all damages caused by the mixed-use
of terminals.
Attention
Moisture and dust can damage the inverter, ensure the cable gland is securely tightened
during installation. The warranty claim will be invalidated if the inverter is damaged as a
result of a poorly connected cable connector.
1. The following must be considered when making electrical connections to the inverter:
① Disconnect the AC breaker switch on the grid side.
② The DC switch of the inverter must be turned to the "OFF" position.
③ For best practice, ensure PV modules of the same model and speci󽗉cations are connected
in each string.
④ Make sure the maximum output voltage of each PV string does not exceed 1100V.
4.5.1 Inverter PV string connection
4 Installation
2.DC connector assembly procedure
① Select the appropriate photovoltaic cable:
Cable type Traverse area (mm²)
General photovoltaic
cable
Range (mm2) Recommended value (mm2)
2.5-4.0 4.0
Figure 4-14
② Peel o󽗈 the DC cable insulation sleeve for 7 mm, as shown in Figure 4-14:
Wire Traverse area 2.5-4mm27mm
③ Disassemble the connector in the accessory bag, as shown in Figure 4-15:
④ Insert the DC cable through the DC connector nut into the metal terminal and press the ter-
minal with a professional crimping plier (pull back the cable with some power to check if the
terminal is well connected to the cable), as shown in Figure 4-16:
Figure 4-15
+
-
4 Installation

28 29
⑤ Insert the positive and negative cables into the corresponding positive and negative con-
nectors, pull back the DC cable to ensure that the terminal is tightly attached in the connec-
tor.
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 4-17:
3. Insert the positive and negative connectors into the inverter DC input terminals respec-
tively, a click sound should be heard if the terminals are well connected, as shown in Fig-
ure 4-18:
Figure 4-16
Crimping Plier
Figure 4-17
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 Installation
Figure 4-18
DC Switch
Inverter
PE
PE
L
N
To grounding electrode
-
-
+
+
Grid
AC Breaker
DC INPUT AC OUTPUT
Figure 4-19
4. Seal the unused PV terminals with the terminal caps.
5. 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,
as shown in Figure 4-19:
4 Installation
COM2-1
COM2-2

30 31
4.5.2 Connection of AC output
Before connecting to the power grid, make sure that the power grid voltage and frequen-
cy meet the requirements of the inverter. See technical parameters for details.
This inverter includes an integrated residual current device (RCD).
If an external residual current device (RCD) is used, a device of type (A/AC etc.) should be
used, 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:
Figure 4-20
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
mm2
2.5-10
mm2
2.5-10
mm2
4-10
mm2
4-10
mm2
4-10
mm2
6-10
mm2
8-10
mm2
8-10
mm2
8-10
mm2
Breaker 20A 20A 20A 20A 32A 32A 32A 40A 40A 50A
Warning
An AC breaker must be connected on the AC side of the inverter.
Any loads cannot be connected to the inverter without the AC breaker.
1. AC connector connection steps
① Take the AC connector out of the accessory bag and disassemble it, as shown in Figure
4-20:
4 Installation
Cable Gland Threaded Sleeve AC Terminal Head
Figure 4-21
Figure 4-22
③ Insert the stripped end of the 󽗉ve wires into the appropriate hole of the terminal head
by following the rules: yellow green wire to PE port, red or brown 󽗉re wires to L ports (no
requests for the sequence of three 󽗉re wires), and blue or black wire to the N port. Please
try to pull out the cable to make sure it is well connected. As shown in Figure 4-22:
② According to the table above, select an appropriate cable, peel the insulation sleeve of
AC cable o󽗈 for 50mm, and peel o󽗈 the end of 3L /PE / N wires for 8mm, as shown in Fig-
ure 4-21:
4 Installation
Strip Length:8mm
50mm
Wire Diameter:13-18mm
Allen Key

32 33
④ According to the arrow direction push the threaded sleeve to make it connected with
the AC terminal head and then rotate the cable gland clockwise to lock it, as shown in 󽗉g-
ure 4-23:
Figure 4-23
Figure 4-24 Connect the AC connector
2. Connect the AC connector to the inverter AC terminal, and rotate the AC connector
buckle clockwise until its tight enough. As shown in 󽗉gure 4-24:
4 Installation
※ 4.6 Monitoring Device Installation
Sunways STT 4-25kW series three phase inverter supports WIFI, GPRS, LAN, 4G and RS485
communication.
Plug the WIFI, LAN, 4G or GPRS module into the COM1 port in the bottom of inverter (as
shown in Figure 4-25). A slight "click" sound during the installation represents that the
assembly is in place.
Figure 4-25 Monitoring device installation
4 Installation
Note
1. The 4G, and GPRS version module does not need to be con󽗉gured.
2. The WiFi version module needs to be con󽗉gured to the router for the 󽗉rst installation.
If the router name or password are changed, the WiFi dongle will need to be recon󽗉g-
ured. For details, please refer to the [QUICK INSTALLATION GUIDE] which is attached to
the accessory bag.
3. If DHCP is enabled on the router, the LAN version module does not need to be con󽗉g-
ured. Otherwise, please refer to the [QUICK INSTALLATION GUIDE] which is attached to
the accessory bag.
Attention
Do not touch the waterproof plug in the card slot except for replacing the SIM card. In
that case, please make sure the card slot is completely sealed by the weatherproof plug
after replacing the SIM card. Any damages caused by improper waterproof plug place-
ment, will void warranty.

34 35
※ 4.7 Meter/RS485/DRED Connection
Figure 4-26
Note
Port 1 Port 2 Port3
Meter Port RS485 Port DRED Port
① This port is available on export limitation & control, RS485 and DRED versions of the
inverter only.
② The Pin connector in inverter Port1 and Port2 may vary from 2Pin to 3pin according to
the shipment version.
Inverter communication ports are located at the behind of the COM2 plate at the bottom
and include RS485 port (used for Meter or Datalogger connection), and DRED port, as
shown in Figure 4-26:
4.7.1 Terminals de󽗉nition
4 Installation
1 1
1
3
5
2 2
3 3
2
4
6
Port 1 Port 2
Port 3
Di󽗈erent versions of the inverter have di󽗈erent terminals, which are de󽗉ned as follows:
Port Function NO. De󽗉nition
Port1
① Only Export limitation & control ver-
sion with this port.
② Connect external Meter (with 3CTs)
to activate the Export Limitation & con-
trol function on Sunways STT series
inverter.
1 RS485 A
2 RS485 B
3 PE/NULL
Port 2
① Export limitation & control/RS485/
DRED version with this port.
② ln case of multiple inverters, all the
inverters can be daisy-chained via
RS485 cables.
1 RS485 A
2 RS485 B
3 PE/NULL
Port 3
① Only DRED version with this port.
② DRED means demand response en-
able device. The AS/NZS 4777.2:2015
requires inverters to support demand
response mode (DRM). This function
is for inverters that comply with AS/
NZS4777.2:2015 standard.
③ Sunways inverter is fully compliant
with all DRM. The 6pin connector is
used for DRM connection.
④ Support DRM command: DRMO,
DRM5, DRM6, DRM7, DRMB.
1 COM/DRMO
2 REFGEN
3 DRM4/8
4 DRM3/7
5 DRM2/6
6 DRM1/5
STT series three-phase inverter supports multiple inverters daisy-chain connection to a
data logger via RS485 communication.
Multiple inverters connection diagram as shown in Figure 4-27:
4.7.2 RS485 Communication
4 Installation

36 37
The maximum distance between the inverter at the end of the daisy chain and the Data
logger should be within 1000m.
Export limitation & control or power limit solution, wiring instructions and con󽗉guration,
please contact Sunways after-sales at [e-mail].
① Remove the COM2 plate in the bottom of the inverter with a cross screwdriver.
② Put the cable through the connector and connect to the terminal in the following or-
der: screw cap, sealing ring, insulator, metal plate, nut and 3/6pin connector, as shown in
Figure 4-28:
Figure 4-27
Attention
It is recommended to use the RS485 communication cable with a cross sectional area of
0.75-1.5mm2 and an outer diameter of 5mm-10mm.
RS485 cable requirements: Shielded twisted-pair cable or shielded twisted Ethernet ca-
ble.
4.7.3 Export limitation & control or power limit solution
4.7.4 Wiring Steps:
4 Installation
STT 4~25KTL
series inverter STT 4~25KTL series inverter STT 4~25KTL series inverter
Data logger
Sunways server
InternetInternet
LAN/WiFi
/GPRS RS485 RS485 RS485
Router
...
Figure 4-28
Figure 4-29
③ Insert the cable to the port in the 3/6pin connector and fasten with a screwdriver.
④ Insert the 3/6pin connector into the 3/6pin connecter inside the inverter, and screw the
COM2 plate back with a cross screwdriver, as shown in Figure 4-29:
4 Installation
20-25mm
1
3
3
1
2
4
6
2
2
1
3
5
Port 1
Port 2
Port 3
6mm
6mm
20-25mm
Screw cap
Sealing ring
Insulator ring
Metal plate
3/6pin connector
Nut

38 39
5 Start and Stop
5 Start and Stop
※ 5.1 Start the Inverter
When starting the inverter, follow these steps:
① Turn on the AC breaker 󽗉rst (close the AC circuit breaker).
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 in-
verter will initiate checking its internal parameters and grid parameters, if it is within the
range, the green light on the left side of the screen begins to 󽗊ash, 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 the Inverter
When turning o󽗈 the inverter, please follow the steps below:
① Turn o󽗈 the AC breaker 󽗉rst.
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 conducting any work on the inverter.
③ Disconnect the AC and DC cables.
6 General Operation
※ 6.1 Display Operation
When the inverter is turned on, the following interfaces will be displayed on the OLED dis-
play, and the OLED display allows the user to check various operation information and to
modify the settings of the inverter. Please refer to the following display operation 󽗊ow for
details:
6 General Operation
Main Window
PV Voltage
PV Current
Grid Voltage
Grid Current
Grid Freq
E-Day E-Total H-Total Model
Name
General
Settings
System InfoFault InfoRSSISafety Set
Setting Error
Message
SN/FM
Version
Export
Limit
Feed in
Grid Power Factor
Setting Setting SettingSetting
Modbus
Addr
Setting
Time Set Language
Set
Setting Setting
Setting
Re-Connect
Setting
Wai�ng Checking Normal Fault Info
Firmware
Upda�ng
Short press(1s),switch window
Long press(3s),enter the lower Menu
Not WiFi/LAN
LAN setting
WIFI setting
OR OR
CT Ratio
Grid Connect
Type Set
6.1.1 Main Window and General Setting