Sunways STH 15-33KTL-HT User manual

SUNWAYS TECHNOLOGIES CO., LTD.
Hybrid Inverter
STH 15-33KTL-HT
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 …………………………………………………… 16
3.3 Display Interface ………………………………………………… 18
3.4 Packing List ………………………………………………………… 19
4 Installation………………………………………………………22
4.1 Location …………………………………………………………… 22
4.2 Mounting the Inverter …………………………………………… 24
4.3 Electrical Connection …………………………………………… 26
4.4 Meter and CT connection ………………………………………… 41
4.5 Communication Connection …………………………………… 44
4.6 Monitoring Device Installation ………………………………… 50
5 Start and Stop …………………………………………………51
5.1 Start the Inverter ………………………………………………… 51
5.2 Stop the Inverter ………………………………………………… 51
6 General Operation………………………………………………52
6.1 Display Operation ………………………………………………… 52
6.2 Country Code (Safety Code) Setting ………………………… 56
6.3 Auto-Test …………………………………………………………… 56
6.4 Online Monitoring APP …………………………………………… 57
7 Troubleshooting ………………………………………………58
7.1 Error Message ……………………………………………………… 58
7.2 Maintenance ……………………………………………………… 63
8 Technical Parameters …………………………………………64
CONTENTS

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Attention
The products, services or features purchased 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 and 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.
1 Preface
※ 1.1 Overview
This manual is an integral part of Sunways STH 15-33kW series three-phase high-voltage hybrid
inverters (hereinaer referred to as the inverter). It mainly introduces the assembly, installation,
electrical connection, debugging, maintenance and troubleshooting of the products. Before
installing and using hybrid inverters, please read this manual carefully, understand the safety
information and be familiar with the functions and characteristics of hybrid inverters.
※ 1.2 Target Groups
This manual is applicable to the electrical installers with professional qualications and the people
who bought it. If there are any problems in the installation process, please call Sunways service
telephone at [phone] or email Sunways at [e-mail] for consultation.

6 7
2 Safety Instructions
※ 2.1 Safety Notes
1. Before installation, please read this manual carefully and follow the instructions in this manual
strictly.
2. Installation operator need to undergo professional training or obtain electrical related
professional 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 components without
authorization may cause injury to people, damage to inverters and annulment 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.
9. When wiring the lithium battery terminals, please disconnect the breaker or switch of the lithium
battery in case of a physical injury caused by the high-voltage.
※ 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 untrained
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 specified in applicable technical
specications.
7. Damages caused by unauthorized disassembly, alteration of products or modication of soware
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
Table below shows the symbols that may appear in this document and their denition:
Symbol Description
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 personal injury.

8 9
※ 2.4 Symbols Explanation
This chapter mainly elaborates the symbols displayed on the inverter, nameplate and packing box.
Symbol Description
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 2.4.1Symbols on the Inverter
Symbol Description
Power indicator.
Grid status indicator.
Inverter status indicator.
Battery level indicator.
2.4.2 Symbol on the Inverter nameplate
Symbol Description
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 aer being disconnected from the mains
and PV input.
CE mark, the inverter complies with the requirements of the applicable CE guidelines.
TUV certication.
Danger. Risk of electric shock!
Symbol Description
Grounding symbol, the inverter casing needs to be properly grounded.

10 11
Figure 3-1 Applicable grid types
Symbol Description
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
Symbol Description
Handle with care.
This side up.
Keep dry.
Stacked layers.
3 Product Description
3.1.2 Models
The STH 15-33kW series hybrid inverter includes 7 models which are listed below:
STH-15KTL-HT、STH-17KTL-HT、STH-20KTL-HT、STH-25KTL-HT、STH-29.9KTL-HT、STH-30KTL-HT、STH-33KTL-HT.
3.1.3 Applicable grid type
The applicable grid types of the Sunways STH 15~33kW 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:
TN-S
Sunways
STH Series
Transformer
TN-C
Sunways
STH Series
Transformer
TN-C-S
Sunways
STH Series
Transformer
TT
Sunways
STH Series
Transformer
※ 3.1 Basic Features
3.1.1 Function
The Sunways STH series inverter is also known as hybrid inverter or storage inverter, which is mainly used to combine
the PV array, lithium battery, loads and power grid to realize intelligent power management and dispatching.

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Figure 3-2 Schematic diagram of hybrid system
PV Array STH 15-33KTL-HT
CT
Meter
Three Phase Storage
Inverter
Back-up Loads
GridOn-grid Loads
High-voltage
Lithium Battery
AC
RS485
DC
3.1.4 Schematic diagram of hybrid system
The hybrid solar system is usually composed of the PV array, hybrid inverter, lithium battery, loads
and power grid. As shown in the Figure 3-2:
3.1.5 Operation modes
Sunways STH Hybrid inverter has the following basic operation modes and you can congure the
operation mode as per your preference in the App.
PV
Inverter
Loads
GridBattery
In this working mode, when the power from
the PV array is sufficient, PV power will supply
the loads, battery, and grid by the following
sequence:
Loads＞Battery＞Grid.
PV power will supply the loads rst, and secondly
charge the battery, and then feed to the grid.
(You can set the power to the grid to 0W if the
local grid doesn’t allow).
When the PV power is insuicient, the battery will
discharge to supply loads, and the grid will join in if
the battery is not enough to supply loads.
When the loads consumption more than the
Pmax, the power exceeded Pmax (cannot be
higher than the inverter max output power) will
be supplied by the inverter.
Inverter will use power from PV array to supply
loads rst and battery second if it isn't enough.
Mode 1
Mode 2
Screen Setting step:
1. General Settings → WorkMode Set → General Mode
2. Advanced Settings →Peakload Shiing →ON
3. Advanced Settings →Set MaxGrid → XXX (kVA)
APP Setting step:
General Mode → To Set → Peakload Shiing ON → Set
Max Grid (kVA)
PV
Inverter
Loads
GridBattery
In this working mode, set the Pmax from grid in the App can realize the“Peakload Shiing”.
PV
Inverter
Loads
GridBattery Pload≥Pmax
PV
Inverter
Loads
GridBattery

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*To realize the “Peakload Shiing” function, the load power that exceeded Pmax has to be within the inverter max
output power, otherwise, the inverter will only output the max power which allowed.
In this working mode, the inverter will use the
power from PV or grid (Set in the App) to charge
the battery until it is fully charged, and as long
as the grid is there, the battery won't discharge.
When the grid is cut off, power from PV and
battery will supply loads connected in the back-
up side (UPS).
Mode 3
×
PV
Inverter
Loads
GridBattery
In this working mode, you can set charge/
discharge power and time in the App, inverter
will use the power from PV or grid (whether to
use can be set in the App) to charge the battery
in the predetermined period.
Mode 4
PV
Inverter
Loads
GridBattery
In the purely o-grid mode, power from PV will
supply the back-up loads first and then charge
the battery if there's surplus.
Mode 5
Inverter will use power from PV and battery to
supply loads in the predetermined period and
the insuicient part will be supplied by the grid.
PV
Inverter
Loads
GridBattery
O󽗈-grid Overloading Ability Illustration
Status Mode Phase 1 Phase 2 Phase 3 Duration
O-grid
Balance Output Mode
1.1 times 1.1 times 1.1 times Continuous
2 times 2 times 2 times 60s
Unbalance Output Mode 1.25 times** 1.25 times** 1.25 times** Continuous
* The multiples above are calculated based on rated output power.
**
Only one of the three phases can reach up to 1.25times, and the other two phases should be less than 1.1times.
When the power from PV isn't enough, the
battery will discharge to supply back-up loads
together with PV.
No Grid
PV
Inverter
Loads
Battery
No Grid
PV
Inverter
Loads
Battery
3.1.6 O-grid output ability (UPS ability)
Sunways STH hybrid inverter overloading ability in o-grid work mode describes as following:

16 17
3.1.7 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 4 levels.
※ 3.2 Physical Layout
Figure 3-3 Front view
3.2.1 Inverter front view
3.2.2 Inverter side view
Figure 3-4 Side view
Figure 3-5 Bottom view
3.2.3 Inverter bottom view
Logo
Display
DC Switch (Optional)
DC Input Terminal Com1 Port
Com2 Port
Battery Input Terminal Back-up Output Terminal
On-grid Output Terminal
Item Terminal Note
1 DC Input Terminal PV connector
2 Battery Input Terminal Battery connector
3COM1 Port WiFi/LAN/GPRS/4G device connector
4 COM2 Port Meter/BMS/RS485/DRED connector
5On-grid Output Terminal Used for On-grid output cable connection
6Back-up Output Terminal Used for Back-up output cable connection
Wiring terminals are at the bottom of the inverter, as shown in the table below.
291mm
430mm
640mm
490mm
291mm

18 19
Item Indicator Status Description
1
Battery
Level
Indicator
O Battery not connected or communication fault.
Always on Battery is discharging or waiting, indicator shows battery level.
Single indicator ash Battery is charging, indicator shows battery level.
※ 3.3 Display Interface
No. Denition
1Battery Level Indicator
2 Power Indicator
3 Grid Indicator
4Alarm Indicator
5 Display
6 Button
Figure 3-7 Display interface
24
1
5
3
6
Item Indicator Status Description
2Power
Indicator
O Inverter no AC output.
Quick ashing Inverter entered self-test status.
Slow ashing Inverter entered waiting status.
Always on Inverter works normal.
3Grid
Indicator
O Disconnected with grid.
Slow ashing Inverter detected grid but not running in on-grid mode.
Always on Inverter works in on-grid mode.
4Alarm
Indicator
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.
Orange A Warning is detected but inverter still working, view the fault info
on the display.
Red An alarm or fault is detected, view the fault info on the display.
5 Display
On Display the inverter operation information.
O Display o to save power, press the button to wake up the display.
6 Button Physical button Switch display information and set parameters by short press or
long press.
※ 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.
Figure 3-6 Inverter back view
3.2.4 Inverter back view
Back Rail
Back Rail
Back Rail
Back Rail

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Figure 3-8 Packing list
M10 Bracket Screw × 4PV Terminal × 4
PV Terminal M10 Bracket Screw
Sunways Meter B with 3 CTs ×1
Cord End Terminal × 8
Sunways Meter B (Optional)
Sunways Meter A with 3 CTs ×1
Cord End Terminal × 8
Sunways Meter A (Optional)
PE Terminal× 1
PE Teminal
6Pin Terminal × 2
AC Terminal × 2
Monitoring Device (Optional) × 1
Inspection
Report
AC Terminal
6Pin Terminal Monitoring Device (Optional)
Inspection Report × 1
Inspection Report
Inverter×1 Back Bracket×1
Battery Plug× 1
Battery Plug

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Figure 4-1 Recommended installation location
4 Installation
※ 4.1 Location
The Sunways STH 15-33kW series inverters designed with IP65 protection enclosure for indoor and
outdoor installations. When selecting an inverter installation location, the following factors should
be considered:
1) The wall or installation bracket 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 exposure to sunlight and
rain.
4) Install the inverter at eye level for easy inspection of screen data and further maintenance.
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 reaching of children.
Recommended installation location of the inverter, as shown in Figure 4-1:
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:
4.1.1Installation location
Warning
Do not put ammable and explosive articles around the inverter.
4.1.2 Installation spacing
Figure 4-2 Recommended installation spacing
Figure 4-3 Recommended installation angle
4.1.3 Installation angle
1000mm 800mm
800mm
500mm
500mm
500mm
500mm

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※ 4.2 Mounting the Inverter
Figure 4-4 Dimensions of wall bracket
4.2.1 Wall bracket installation
Dimensions of wall bracket, see Figure 4-4:
1)Use the inverter back bracket as the template to mark the position of 4 holes on the installation
bracket.
2)Use an electrical driller with 12mm diameter bit to drill 4 holes on the installation
bracket. See Figure 4-5 for details:
Figure 4-5 Mark the hole position and drill holes
Figure 4-6 Fixing the bracket
3) Follow the instructions in the picture below to install the M10 bracket screws (bolt,
spring washer, at washer) and tighten the bolts with torque wrench in the torque of 35-
40N.m, see Figure 4-6 for details:
Figure 4-7 Mounting the inverter
Li the inverter, hang the back rail on the xed back bracket carefully. See Figure 4-7 for details:
4.2.2 Mounting the inverter
218mm
294mm
310mm
509.5mm

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※ 4.3 Electrical Connection
4.3.1 Sunways STH hybrid inverter electrical wiring diagram
This diagram shows Sunways STH 15~33kW series hybrid inverter wiring structure and composition,
concerning the real project, the installation and wiring have to be in line with the local standards.
Symbol Description
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 serious damage
to the inverter.
Warning
Static may cause damage to the electronic components of the inverter. Anti-static measures should
be taken during installation and maintenance.
Attention
Do not use other brands or other types of terminals other than the terminals in the accessory
package. Sunways has the right not to undertake quality assurance for 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 damaged by the cable connector
not well installed.
Figure 4-8

28 29
Single inverter wiring diagram
This diagram is an example without special requirement on electrical wiring connection.
Neutral line of AC supply can be isolated or switched.
If you get Sunways meter A, please refer to Figure 4-9A：
Figure 4-9A Standard wiring diagram
If you get Sunways meter B, please refer to Figure 4-9B：
Figure 4-9B Standard wiring diagram

30 31
Figure 4-10A Australia wiring diagram
This diagram is an example for Australia and New Zealand. Neutral line of AC supply must
not be isolated or switched.
For Sunways meter A, please refer to Figure 4-10A:
4 Product Installation
Figure 4-10B Australia wiring diagram
For Sunways meter B, please refer to Figure 4-10B:

32 33
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 performance. Inverters
must be well-grounded.
For a system with only one inverter, just ground the PE cable.
For a multi-inverter system, all inverters PE wire need to be connected to the same grounding
copper bar to ensure equipotential bonding.
Figure 4-11 Grounding terminal 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 4-11.
4.3.2 External ground connection
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 specifications are connected in each
string.
4) Make sure the maximum output voltage of each PV string does not exceed 1000V.
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 4-12:
4.3.3 Inverter PV string connection
Figure 4-12
Wire Traverse area 2.5-4mm27mm
Cable type Traverse area (mm2)
General photovoltaic cable
Range (mm2) Recommended value (mm2)
2.5-4.0 4.0

34 35
3) Disassemble the connector in the accessory bag, as shown in Figure 4-13:
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 if the terminal is
well connected to the cable), as shown in Figure 4-14:
+
-
Crimping Plier
Figure 4-13
Figure 4-14
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 4-15:
Figure 4-15
Open-end Wrench
Figure 4-16
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 4-16:
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.

36 37
1.The following principles must be considered when making battery connection:
1) Disconnect the AC breaker on the grid side.
2) Disconnect the breaker on the battery side.
3) Turn the inverter DC switch to the “OFF” position.
4) Make sure the maximum input voltage of battery is within the inverter limitation (135~800V).
2.Lithium battery connector assembly procedures
1) Select an appropriate battery cable
4.3.4 Inverter battery connection
2) Peel o the battery cable insulation sleeve for 12 mm, as shown in Figure 4-17:
3) Disassemble the connector in the accessory bag, as shown in Figure 4-18:
Cable type Conductor cross-sectional area (mm²)
AWG 4
Outside diameter (mm) Conductor core section (mm²)
9-10.5 25
Wire Outside diameter 9-10.5mm212mm
Figure 4-17
Figure 4-18
4) Insert the battery cable through the battery connector nut, then into the metal terminal. Press the
terminal with a professional crimping plier (pull back the cable with some power to check if it’s tight
enough), as shown in Figure 4-19:
Figure 4-19
Push the metal terminal into the battery connector. Ensure A ”click” sound be heard, which mean
assembly in place. Screw the battery connectors tightly with hand.
Warning
1.Before making the battery connector, please make sure the polarity of the cable is correct.
2.Use a multimeter to measure the voltage of the battery pack and make sure the voltage is within
the inverter limitation and the polarity is correct.
5) Insert the positive and negative connector into the inverter battery terminals respectively.
The arrow on connector should point to arrow on the inverter battery terminal. A “click” sound
represents the assembly in place, as shown in Figure 4-20:
Crimping Plier

38 39
Figure 4-20
1. The following principles must be considered when making AC output connection:
1) An independent AC breaker is required at both on-grid and back-up output side, and any loads
cannot be connected with inverter directly.
2) Before making the connection of AC cable, please confirm all DC & AC power source are
disconnected from the inverter.
3) 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.
2. AC connector assembly procedures
The recommended AC cable and AC breaker for Sunways STH 15~33kW series three-phase hybrid
inverter are as shown in the following table:
4.3.5 Connection of AC output Figure 4-21
Figure 4-22
Model STH-15KTL-
HT
STH-17KTL-
HT
STH-
20KTL-HT
STH-25KTL-
HT
STH-
29.9KTL-HT
STH-30KTL-
HT
STH-33KTL-
HT
Copper Cable
Conductor core
section
(mm²)
6-10 8-10 8-10 16-25 16-25 16-25 16-25
AC Circuit Breaker
(A) 32 40 40 50 63 63 63
1) According to the table above, select an appropriate AC cable, peel o the insulation sleeve of AC
cable for 95-100mm, and peel o the sleeve in the conductor core of 3L/PE/N wires for 20~25mm, as
shown in Figure 4-21:
2) Thread the stripped wire into the lock nut and the main body in turn (the exible wire
needs to be riveted to the insulated terminal), as shown in Figure 4-22: