Sunways STS-3KTL User manual

Grid-connected PV Inverter
Single Phase Dual MPPT
User Manual
Ningbo Sunways Technologies Co., Ltd.
STS-3K/3.6K/4.2K/4.6K/5K/6KTL

CONTENTS
1.Preface .........................................................................................................................5
1.1 Overview ........................................................................................................5
1.2 Target Groups ................................................................................................5
2.Safety Instructions .................................................................................................5
2.1 Safety Notes ..................................................................................................5
2.2 Statement ......................................................................................................5
2.3 Important Safety Matters .............................................................................6
2.4 Symbols Explanation ....................................................................................7
3. Product Introduction ...........................................................................................9
3.1 Basic Features ...............................................................................................9
3.2 Appearance Introduction ...........................................................................10
3.3 Display Interface .........................................................................................12
3.4 Packing list...................................................................................................13
4. Product Installation ............................................................................................13
4.1 Selection of Installation Location ..............................................................13
4.2 Mounting the Inverter .................................................................................15
4.3 Electrical Connection .................................................................................17
4.4 Monitoring Device Installation ...................................................................22
4.5 Power Limiting Device & DRED Connection ..............................................23
4.6 System Layout of Units Without Integrated DC Switch ............................25
5. Start and Stop .......................................................................................................25
5.1 Start the Inverter .........................................................................................25
5.2 Stop the Inverter .........................................................................................25
6. General Operation ...............................................................................................26
6.1 Display Operation .......................................................................................26
7. Troubleshooting...................................................................................................27
7.1 Fault Messages ............................................................................................27
8. Technical Parameters ........................................................................................28

Attention
The products, services or features you purchase are subject to the commercial
contracts and terms of Ningbo Sunways technologies Co., Ltd. All or part of the
products, services or features described in this document may not be within your
purchasing or using scope. Unless otherwise agreed in the contract, the Company
shall not make any express or implied declaration 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.
Manufacturer: Ningbo Sunways technologies Co., Ltd.
Address: No. 1, Second Road, Green Industrial Zone, Chongshou Town,
Cixi City, ZheJiang Province, PEOPLE’S REPUBLIC OF CHINA
Website: www.sunways-tech.com
Service Mail: [e-mail]
Hotline: [phone]

1.Preface
1.1 Overview
This manual is an integral part of Sunways STS 3-6kW series single-phase inverters (hereinafter
referred to as the inverters). It mainly introduces the assembly, installation, electrical
connection, debugging, maintenance and troubleshooting of the products. Before installing
and using inverters, please read this manual carefully, understand the safety information and
be familiar with the functions and characteristics of inverters.
1.2 Target Groups
This manual is applicable to the electrical installers with professional quali󽗉cations and the
people who bought this inverter. If there are any problems in the installation process, please
call Sunways service telephone at [phone] or email Sunways at service@sunways-
tech.com for consultation.
2.Safety Instructions
2.1 Safety Notes
2.1.1 Before installation, you should read this manual carefully and follow the instructions in
this manual strictly.
2.1.2 Installation operators need to undergo professional training or obtain electrical related
professional quali󽗉cation certi󽗉cates.
2.1.3 When installing, do not touch any part of the inner part of the inverter except the
terminals.
2.1.4 All electrical installations must conform to local electrical safety standards.
2.1.5 If the inverter needs maintenance, please contact the local designated personnel for
system installation and maintenance.
2.1.6 To use this grid-connected inverter for power generation needs the permission of the
local power supply authority.
2.1.7 During the operation of the inverter, the surface temperature may be higher and there is
a risk of burns. Do not touch.
2.1.8 When installing photovoltaic panels in the daytime, the photovoltaic panels should be
covered with opaque materials to avoid the risks and danger of high voltage at the panel end
in sunlight.
2.2 Statement
Ningbo Sunways technologies Co., Ltd. has the right not to undertake quality assurance in any
of the following circumstances:
2.2.1 Damages caused by irregular transportation.
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2.2.2 Damages caused by incorrect storage, installation or use.
2.2.3 Damages caused by installation and use of equipment by non-professionals or untrained
personnel.
2.2.4 Damages caused by failure to comply with the instructions and safety warnings in the
products and documents.
2.2.5 Damages of running in an environment that does not meet the requirements stated in
the document.
2.2.6 Damages caused by operation beyond the parameters speci󽗉ed in applicable technical
speci󽗉cations.
2.2.7 Damages caused by unauthorized disassembly, alteration of products or modi󽗉cation of
software codes.
2.2.8 Damages caused by abnormal natural environment (force majeure, such as lightning,
earthquake, 󽗉re, storm, etc.).
2.2.9 Any damages caused by the process of installation and operation which don’t follow the
local standards and regulations.
2.2.10 Products beyond the warranty period.
2.3 Important Safety Matters
The following symbols may appear in this manual, which represent the following meanings:
Danger
Warning
Caution
Used to warn of urgent dangerous situations, if not avoided, it
could result in death or serious personal injury.
DescriptionSymbol
Used to warn of potentially dangerous situations, if not
avoided, it may result in death or serious personal injury.
Used to warn of potentially dangerous situations, if not
avoided, it may result in moderate or minor personal injury.
Attention
Used to transmit the safety warning information about
equipment or environment, if not avoided, it may cause
equipment damage, data loss, equipment performance
degradation or other unpredictable results. "Attention" does
not involve personal injury.
Note Used to highlight important information, best practices and
tips, etc. it's not warning, doesn't involve personal injury and
equipment damage information.
6

2.4.2 Symbol on the Inverter nameplate
The inverter cannot be disposed of with household waste.
DescriptionSymbol
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.
Danger. Risk of electric shock!
TUV certi󽗉cation.
SAA certi󽗉cation.
The surface is hot during operation and no touch is allowed.
Electric shock hazard, it is strictly forbidden to use the person
to disassemble the inverter casing.
2.4 Symbols Explanation
This chapter mainly elaborates the symbols displayed on the inverter, nameplate and packing
box.
2.4.1 Symbols on the Inverter
Inverter status indicator.
Description
Symbol
Inverter running indicator.
Grounding symbol, the inverter casing needs to be properly
grounded.
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8
Handle with care.
DescriptionSymbol
This side up.
Keep dry.
Stacked layers.
2.4.3 Symbol on the Packing box

Figure 3-1 Applicable grid type
STS Single Phase STS Single Phase
STS Single Phase STS Single Phase
3. Product Introduction
3.1 Basic Features
3.1.1 Function
The Sunways STS 3~6kW series is a single-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 The STS 3~6kW series inverter contains 6 models which are list below:
STS-3KTL, STS-3.6KTL STS-4.2KTL, STS-4.6KTL, STS-5KTL, STS-6KTL.
3.1.3 Applicable grid type
The applicable grid types for the Sunways STS 3~6kW series are TN-S, TN-C, TN-C-S and TT.
When applied to the TT grid, the voltage of N to PE should be less than 30V. See Figure 3-1 for
details:
3.1.4 Storage conditions
1) Inverter must be stored in its original packaging.
2) The storage temperature should be in the range of -30 ° C and + 60 ° C, and the relative
humidity stored is less than 90%.
3) If a batch of inverters needs to be stored, the height of each pile should be no more
than 6 levels.
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Figure 3- 2 Front view
Figure 3- 3 Side view
3.2 Appearance Introduction
3.2.1 Inverter front view, as shown in Figure 3- 2:
3.2.2 Inverter side view, as shown in Figure 3-3:
360mm
410mm
Logo
Display
Name
Plate
360mm
120mm
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Figure 3-4 Bottom view
Figure 3-5 Inverter back view
3.2.3 Inverter bottom view, as shown in Figure 3- 4:
3.2.4 Inverter back view, as shown in Figure 3- 5:
Back Rail
Vent Valve
120mm
DC Switch
DC Input Terminal
Back Rail
Com Port
AC Output Terminal

sunways
3.3 Display Interface
Figure 3-6 Display interface
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.
Always on Normal, grid-connected and power generated.
2Alarm
Indicator
Always on An alarm or fault is detected, and the display can view the
speci󽗉c fault information.
O󽗈 The inverter is running normally.
Slow 󽗊ashing The monitoring device is not connected to the router or is
not connected to the base station.
Quick 󽗊ashing
The monitoring device is connected to the router or
connected to the base station but not connected to the
server.
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.
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13
Inspection Report
Quick Guide
Grid Licence
Inverter × 1 Wall Bracket × 1 Expansion Bolt × 4
2Pin Terminal × 1
for Anti-reverse
version PV Terminal × 2
Figure 3- 7 Packing list
3.4 Packing list
The package of the inverter includes the following accessories. Please check whether the
accessories in the packing box are complete at the 󽗉rst time when receiving the goods. See
Figure 3-7 for the packing list:
4. Product Installation
4.1 Selection of Installation Location
The Sunways STS 3~6kW series is designed with IP65 protection for indoor and outdoor
installations. When selecting an inverter installation location, the following factors should be
considered:
1) The wall on which the inverter is mounted must be strong and can withstand the weight of
the inverter for a long time.
2) The inverter needs to be installed in a well-ventilated environment.
3) Do not expose the inverter directly to strong sunlight to prevent the power derating due to
excessive temperature.
4) The inverter should be installed in a place with shelter to prevent direct exposure to sunlight
and rain.
5) Install the inverter at the eye level for easy inspection of screen data and further
maintenance.
6) The ambient temperature of the inverter installation location should be between -30 ° C and
60 ° C.
7) The surface temperature of the inverter may reach up to 75 ° C. To avoid risk of burns, do
not touch the inverter while it’s operating and inverter must be installed out of reaching of
children.
4.1.1 Recommended installation location of the inverter, as shown in Figure 4-1:
Monitoring
Device × 1(Optional) AC Terminal × 1 Ground Terminal × 1 6Pin Terminal × 1
Australia only
User Manual × 1
Quick Guide × 1
Inspection Report × 1
Grid Connection Licence × 1

4.1.2 The requirements for inverter installation spacing are shown in Figure 4-2:
4.1.3 The installation angle of the inverter is recommended as shown in Figure 4-3:
Figure 4-1 Recommended installation location
Figure 4-2 Recommended installation space
Figure 4-3 Recommended installation angle
Do not put 󽗊ammable and explosive articles around the inverter.
Warning
300mm
300mm
500mm 500mm
500mm 500mm
300mm
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4.2 Mounting the Inverter
4.2.1 Wall bracket installation
Dimensions of wall bracket, see Figure 4-4:
1) Use the wall bracket as the template to mark the position of 4 holes on the wall. See Figure
4-5 for details:
Figure 4-4 Dimensions of wall bracket
Figure 4-5 Mark the hole position
10mm
16mm
150mm
FRONT
220mm
110mm 110mm
104mm

Figure 4-6 Fix the wall bracket
Figure 4-7 Mounting the inverter
Before drilling, make sure to avoid the buried water tube and
electric wires in the wall to avoid danger.
2) Use an electrical driller with 10mm diameter bit to drill 4 holes on the wall and make sure
hole depth is 80mm.
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:
4.2.2 Mounting the inverter
Lift up the inverter with both hands, hang the back rail on the 󽗉xed wall bracket carefully, see
Figure 4-7 for details:
Warning
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4.3 Electrical Connection
Danger hint
4.3.1 Inverter PV string connection
4.3.1.1 The following principles must be considered when making electrical connections to the
inverter:
1) Disconnect the AC breaker on the grid side.
2) The DC switch of the inverter must be turned to the "OFF" position.
3) The number and type of the PV panels connected in each PV string best to be same.
4) Make sure the maximum output voltage of each PV string does not exceed 600V.
4.3.1.2 DC connector assembly procedure
1) Select the appropriate photovoltaic cable:
2) Peel o󽗈 the DC cable insulation sleeve for 7 mm, as shown in Figure 4-8:
Cable type Conductor transverse area（mm²）
General photovoltaic cable
Scope(mm²) Recommended value
（mm²）
2.5-4.0 4.0
A high voltage in the conductive part of the inverter may cause an
electric shock. When performing any installation on the inverter, make
sure that the AC and DC sides of the inverter are completely
de-energized.
Do not ground the positive or negative pole of the PV string, otherwise
it will cause serious damage to the inverter.
Static may cause damage to the electronic components of the
inverter. Anti-static measures should be taken during the repairing or
installation.
Do not use other brands or other types of terminals other than the
terminals in the accessory package. Sunways has the right to refuse all
damages caused by the mixed-use of terminals.
Moisture and dust can damage the inverter, ensure the cable gland
is securely tightened during installation. The warranty claim will be
invalided if the inverter damaged by the cable connector not well
installed.
Figure 4-8
Wire transverse area 2.5-4mm27mm
Danger
Warning
Attention
Attention
Warning

Figure 4-9
+
-
Crimping Plier
Open-end Wrench
Figure 4-10
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 600V.
Figure 4-11
3) Disassemble the connector in the accessory bag, as shown in Figure 4-9:
4) Insert the DC cable through the DC connector nut into the metal terminal and press the
terminal with a professional crimping plier (pull back the cable with some power to check it’s
tight enough or not), as shown in Figure 4-10:
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 4-11:
Warning
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An AC breaker must be connected on the AC side of the inverter.
Any loads cannot be directly connected to the inverter.
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Figure 4-12
Figure 4-13
Model STS-3KTL STS-3.6KTL STS-4.2KTL STS-4.6KTL STS-5KTL STS-6KTL
Cable 4mm24mm24mm24mm26mm26mm2
Breaker 20A 25A 32A 32A 40A 40A
7) Insert the positive and negative connectors into the inverter DC input terminals respectively,
and when you hear the "click" sound represents the assembly in place, as shown in Figure 4 -12:
4.3.2 Connection of AC output
The Sunways STS 3~6kW series single phase inverter applies to the single-phase power grid
with a voltage of 220/230V and a frequency of 50/60Hz.
The recommended cable and AC breaker for the Sunways STS 3~6kW series single phase
inverter are shown in the following table:
4.3.2.1 AC connector connection steps
1) Take the AC connector out of the accessory bag and disassemble it, as shown in Figure 4-13:
Cable Gland Threaded Sleeve AC Terminal Head
Warning

Figure 4-14
Figure 4-15
Allen Key
Figure 4-16
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 L /PE / N wires for 8mm, as shown in Figure 4-14:
3) Insert the stripped end of each three wire into the appropriate hole of the terminal head
(yellow green wire to PE port, red or brown wire to L port, and blue or black wire to the N port).
Please try to pull out the cable to make sure it’s well connected. As shown in Figure 4- 15:
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 󽗉gure 4-16:
Wire Diameter:10-14mm
50mm
Strip Length:8mm
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