Stealth ST-INV-S3.0 User manual

Suzhou Stealth Energy Technology Co., Ltd.
1
Installation Manual
Grid-Connected Photovoltaic Inverter
(ST-INV-S3.0)
(ST-INV-S5.0)
English-AU ST Series Version: 2.0

Suzhou Stealth Energy Technology Co., Ltd.
2
Contents
1 About This Manual ................................................................................................. 4
1.1 Applicable Model .................................................................................................... 4
1.2 Target Audience ...................................................................................................... 4
1.3 Symbol Definition .................................................................................................... 4
2
Safety Precaution ................................................................................................... 5
2.1 General Safety ........................................................................................................ 5
2.2 PV String Safety ..................................................................................................... 5
2.3 Inverter Safety ....................................................................................................... 6
2.4 Battery Safety ......................................................................................................... 7
2.5 Personal Safety ...................................................................................................... 7
2.6 Safe Transport of Inverter ...................................................................................... 7
3 Product Introduction .............................................................................................. 8
3.1 Overview ................................................................................................................. 8
3.2 Appearance.............................................................................................................. 9
3.3 Dimensions and Weight ........................................................................................... 9
3.4 Nameplate.............................................................................................................. 10
3.5 Application Scenarios.............................................................................................11
3.6 Working Modes ..................................................................................................... 12
3.7 Features ................................................................................................................ 16
4
Check and Storage .............................................................................................. 17
4.1 Check Before Receiving ...................................................................................... 17
4.2 Delivery List............................................................................................................17
4.3 Storage .................................................................................................................. 18
5 Installation Requirements ................................................................................18
5.1 Installation Precautions ......................................................................................18
5.2 Installation Location ...............................................................................................19
5.3 Installation Tools .................................................................................................... 23
5.4 Installing the Inverter..............................................................................................24
6 Electrical connection.............................................................................................26
6.1 Safety Instructions ................................................................................................. 26

Suzhou Stealth Energy Technology Co., Ltd.
3
6.2 System Wiring Diagram .......................................................................................26
6.3 Overview of Electrical Connection ......................................................................... 28
6.4 Terminal Introduction .............................................................................................30
6.5 Connecting the PE Cable ..................................................................................... 31
6.6 Connecting the PV Input ........................................................................................32
6.7 Connecting the Battery Cable ................................................................................37
6.8 Connecting the AC Cable (grid and backup port) ..................................................40
6.9 Connecting the Communication Cable ..................................................................44
7 System Commissioning ......................................................................................49
7.1 Check Before Power On ...................................................................................... 49
7.2 Startup Procedure ................................................................................................49
7.3 Shutdown Procedure ........................................................................................... 49
7.4 System Status ..................................................................................................... 50
7.5 LED Indicator Light ...............................................................................................51
7.6 Setting Up Remote Monitoring .........................................................................52
8 Maintenance ......................................................................................................... 53
8.1 Removing the Inverter ........................................................................................ 53
8.2 Disposing of theInverter .................................................................................... 53
8.3 Troubleshooting ....................................................................................................53
8.4 Routine Maintenance ...........................................................................................61
9 Appendix ................................................................................................................ 62
9.1 Technical Data ...................................................................................................... 62
9.2 Grid Code............................................................................................................... 65
9.3 Quality Assurance .................................................................................................. 66

Suzhou Stealth Energy Technology Co., Ltd.
4
1 About This Manual
This manual describes the product information, installation, electrical connection,
commissioning, troubleshooting, and maintenance. Read through this manual before installing
and operating the product. All the installers and users have to be familiar with the product
features, functions, and safety precautions. This manual is subject to update without notice.
1.1 Applicable Model
This manual applies to the ST series inverters below:
ST-INV-S3.0
ST-INV-S5.0
1.2 Target Audience
This manual applies to trained and knowledgeable technical professionals. The technical
personnel have to be familiar with the product, local standards, and electric systems.
1.3 Symbol Definition
Different levels of warning messages in this manual are defined as follows:
DANGER
Indicates a high-level hazard that, if not avoided, will result in death or serious injury.
WARNING
Indicates a medium-level hazard that, if not avoided, could result in death or serious injury.
CAUTION
Indicates a low-level hazard that, if not avoided, could result in minor or moderate injury.
NOTICE
Highlights and supplements the texts. Or some skills and methods to solve product-related
problems to save time.

Suzhou Stealth Energy Technology Co., Ltd.
5
2 Safety Precaution
Please strictly follow these safety instructions in the installation manual during the operation.
NOTICE
The inverters are designed and tested strictly in compliance with related safety rules. Read
and
follow all the safety instructions and cautions before any operations. Improper operation
might
cause personal injury or property damage as the inverters are electrical equipment.
2.1 General Safety
NOTICE
• The information in this installation manual is subject to change due to product updates or
other reasons. This guide cannot replace the product warning labels unless otherwise
specified. All descriptions here are for guidance only.
• Before installations, read through the installation manual to learn about the product
and the precautions.
• All operations should be performed by trained and knowledgeable technicians who are
familiar with local standards and safety regulations.
• Use insulating tools and wear personal protective equipment when operating the
equipmentto ensure personal safety. Wear anti-static gloves, clothes, and wrist strips
when touching electron devices to protect the inverter from damage.
• Strictly follow the installation, operation, and configuration instructions in this manual.
The manufacturer shall not be liable for equipment damage or personal injury if you do
not follow the instructions.
2.2 PV String Safety
DANGER
Connect the DC cables of the inverter to the delivered DC terminals. Severe damage might
happen if other types of DC terminals are used, which are beyond the manufacturer’s liability.
WARNING
• Ensure the component frames and the bracket system are securely grounded.
• Ensure the DC cables are connected tightly, securely and correctly.
• Measure the DC cables with a multi-meter to avoid reverse polarity connection. Also,
the voltage should be under the permissible range.
• Do not connect one PV string to more than one inverter at the same time. Otherwise, it
may cause damage to the inverter.

Suzhou Stealth Energy Technology Co., Ltd.
6
2.3 Inverter Safety
WARNING
• The voltage and frequency at the connection point meet the inverter grid connection
requirements.
• Additional protective devices like circuit breakers or fuses are recommended on the
DC/AC side. Specification of the protective device should be at least 1.25 times the
maximum current.
• Backupisnot recommended ifthe PV system isnot configured withbatteries.Otherwise,
the risk in system power usage is beyond the equipment manufacturer's warranty scope.
• Make sure that all the groundings are tightly connected.
• Testing to AS/NZS 4777.2:2020 to multiple inverter combinations has not been conducted
that the product is not to be used in multiple inverter combinations.
DANGER
• All labels and warning marks should be visible after the installation. Do not cover, scrawl,
or damage any label on the equipment.
• Warning labels on the inverter are as follows:
Beware of a danger zone
This symbol indicates that the product must be additionally grounded if
additional grounding or equipotential bonding is required at the installation
site
Delayed discharge
Wait 5 minutes after power off until the components are completely
discharged
High-temperature hazard
Do not touch the product under operation to avoid being burnt
Observe the documentations
Read through the installation manual before any operations
WEEE designation
Do not dispose of the product together with the household waste but in
accordance with the disposal regulations for electronic waste applicable
at the installation site
CE marking
The product complies with the requirements of the applicable EU
directives
TÜV mark of conformity

Suzhou Stealth Energy Technology Co., Ltd.
7
2.4 Battery Safety
WARNING
• The battery used with the inverter shall be approved by the inverter manufacturer.
• Before installations, read through the corresponding battery's installation manual to learn
about the product and the precautions. Strictly follow its requirements.
• If the battery discharged completely, please charge it in strict accordance with the
corresponding installation manual.
• Factors such as: temperature, humidity, weather conditions, etc. may limit the battery's
current and affect itsload.
• Contact after-sale service immediately if the battery is not able to be started. Otherwise,
the battery might be damaged permanently.
• Use the multi-meter to measure the DC cable to avoid reverse polarity connection. Also,
the voltage should be under the permissible range.
• Do not connect one battery group to several inverters at the same time. Otherwise, it may
cause damage to the inverter.
2.5 Personal Safety
WARNING
• Personnel who install or maintain the equipment must be strictly trained, learn about
safety precautions and correct operations.
• Only qualified professionals or trained personnel are allowed to install, operate, maintain,
and replace the equipment or parts.
2.6 Safe Transport of Inverter
Transport the inverter in its original packaging, facing up and without exposing it to unnecessary shocks.
If the original package is no longer available, use a similar box that can withstand the weight of the
inverter (refer to the inverter weight in “
9.1 Technical Data ” on page 62), has a handle system and can
be closed fully.

Suzhou Stealth Energy Technology Co., Ltd.
8
3 Product Introduction
3.1 Overview
Function:
Inverters control and optimize the power in PV systems through an integrated energy
management system. The power generated in the PV system can be used, stored in the battery,
output to the utility grid,etc.
Model:
This manual applies to the listed inverters below:
• ST-INV-S3.0
• ST-INV-S5.0
Model description:
ST - INV-S 3.0
1 2 3 4
No.
Referring to
Explanation
1 Brand Code STEALTH ENERGY
2 Product Feature PV Inverter
3 S Single-phase
4 Rated apparent power The rated output power is 3000VA
Supported grid types:

Suzhou Stealth Energy Technology Co., Ltd.
9
3.2 Appearance
The following illustrations are for reference only, please refer to the actual objects.
3.3 Dimensions and Weight
Model
Width [mm]
Height [mm]
Depth [mm]
Net weight [kg]
ST-INV-S3.0 411 505 195 18.6
ST-INV-S5.0 411 505 195 18.6

Suzhou Stealth Energy Technology Co., Ltd.
10
3.4 Nameplate
The nameplate is for reference only
Trademark, product type, and
product model
Technical parameters
Serial number
Safety symbols and marks
Country of manufacture.

Suzhou Stealth Energy Technology Co., Ltd.
11
3.5 Application Scenarios
WARNING
• The PV system is not suitable to connect equipment that relies on a stable power supply,
such as medical equipment to sustain life. Ensure that no personal injury is occurred when
the system is disconnected.
• Avoid loads with high starting current like high-power water pumps in the PV system.
Otherwise, the off-grid output may fail due to excessive instantaneous power.
• Backupisnot recommended ifthe PV system isnot configured withbatteries.Otherwise,
the risk in system power usage is beyond the equipment manufacturer's warranty scope.
• Factors such as: temperature, humidity, weather conditions, etc. may limit the battery's
current and affect itsload.
• The inverter offers EPS (Emergency Power Supply) function, when the mains is de-
energized or disconnected.
• When single overload protection occurs, the inverter can restart automatically; however,
the restarting time will be extended if it happens several times. For a faster restarting, try it
via Stealth ’app setting.
• When the grid is disconnected, the off-grid function of the inverter will be closed
automatically if the load capacity exceeds the inverter's rated power; to enable it, turn off
the large loads and ensure the load power is less than the rated power of the inverter.
• Normal household loads can be supported when the inverter is in backup mode. Accepted
loads as below:
• Inductive loads: 1.5P non-inverter air conditioner can be connected to the inverter. If
two or more non-inverter air conditioners are connected, the EPS may be unstable.
• Capacitive load: total power ≤ 0.6 times of the inverter’s rated output power.

Suzhou Stealth Energy Technology Co., Ltd.
12
3.6 Working Modes
STEALTH ST Series, also known as hybrid or bidirectional solar inverters, is suitable for solar systems
with PV, battery, load and grid systems for energy management. The energy generated by the
photovoltaic system.
The power is first used to provide the load, the excess power can be used to charge the battery, and the
remaining power can be used for grid connection. When the PV power is not sufficient to meet the
requirements, the battery should be discharged to support the load consumption. If both photovoltaic
power and battery power are insufficient, the system will use grid power to support the load.
The above introduction describes the general working of a photovoltaic system. The operation mode can
be adjusted according to the system layout on the Stealth “PV Pro” App. The following are the general
operating modes of photovoltaic energy storage systems.
Depending on your configuration and layout conditions, PV energy storage systems typically have the
following modes of operation:
3.6.1 Self-use mode
The self-use mode is suitable for areas with low feed-in subsidies and high electricity prices.
①When the power of PV is sufficient
PV will power the loads firstly, and surplus power will charge to the battery. If the battery is fully
charged, then sell the surplus power to the grid;
(PV ＞Load, PV → Load → Battery → Grid)
②When the power of PV is insufficient
PV will power the loads firstly, the remaining power will be taken from the grid, the battery will not
discharge at this time.
(PV ＜Load, PV + Grid → Load)

Suzhou Stealth Energy Technology Co., Ltd.
13
PV+BAT will power the loads together. If the power is still not enough, the remaining power will be
taken from the grid.
(PV ＜Load, PV + Battery + Grid → Load)
③Without PV power
The grid supplies the loads and also can charge the battery;
(PV=0, Grid → Load + Battery)
The battery will power the home loads. If the battery power is not enough, the remaining power will
be taken from the grid. The inverter will enter into the standby state.
(PV=0, Battery + Grid → Load)
Battery min SOC can be set:10%-100%
3.6.2 Feed-in priority mode
The Feed-in priority mode is suitable for areas with high feed-in subsidies, but has feed-in power
limitation.
①When the power of PV is sufficient
First, PV supply power to the load, then sell the power to the grid. If the local grid company limits
the grid-connected power of the inverter, the excess energy continues to charge the battery.
(PV ＞Load, PV → Load → Grid → Battery)
PV will power the loads firstly, and surplus power will feed-in to the grid.
(PV ＞Load, PV → Load → Grid)
②When the power of PV is insufficient
PV will power the loads firstly; The battery also will power the home loads. If the battery power is
not enough, the remaining power will be taken from the grid.
(PV ＜Load, PV + Grid → Load)
PV + BAT will power the loads together. If the power is still not enough, the remaining power will be
taken from the grid.

Suzhou Stealth Energy Technology Co., Ltd.
14
(PV ＜Load, PV + Battery + Grid → Load)
③Without PV power
The grid will power the home loads and also charge the battery;
(PV=0, Grid → Load +Battery)
The battery will power the home loads firstly. If the battery power is not enough, the remaining
power will be taken from the grid. The inverter will enter into the standby state.
(PV=0, Battery + Grid → Load)
Battery min SOC can be set:10%-100%
3.6.3 Backup mode
The back-up mode is suitable for areas with frequent grid lose.
This mode will maintain the battery capacity at a relatively high level, to ensure that the emergency
loads can be used when the grid is off. Customers no need to worry about the battery capacity.
Battery min SOC can be set: 10%-100%.
3.6.4 EPS mode (off-grid)

Suzhou Stealth Energy Technology Co., Ltd.
15
The EPS mode is used when the power grid is off.
System will provide emergency power through PV and batteries to supply power to the household
loads.
(Battery must be installed for this mode)
①When the power of PV is sufficient
PV will power the loads firstly, and surplus power will charge to the battery.
(PV ＞Load, PV → Load → Battery)
②When the power of PV is insufficient
The remaining power will be taken from the battery.
(PV ＜Load, PV + Battery → Load)
③Without PV power
The battery will power the emergency loads until the battery reached the min SOC, then the inverter
will enter into the idle mode.
(PV=0, Battery → Load)
EPS SOC-min condition is adjustable within the range of 10%-25%;
NOTICE
in the case of grid connection, all working modes work normally when the battery
SOC >10%. When the battery charge rate is below 10%, the PV or Grid will first charge
the battery SOC15%, and then return to the working mode selected by the user.

Suzhou Stealth Energy Technology Co., Ltd.
16
3.7 Features
3.7.1 Basic information
Model
Number
Series
Type
Number of
Phase
Rated AC
Output
(VA)
Integrated
PV
Isolator
Integrated
PV
Isolator
EESS
Registered
Inverter
Grid
Settings
Access
Method
ST-INV-
S3.0 ST 1 3000 NA NO Monitoring
App
ST-INV-
S5.0 ST 1 4991 NA NO Monitoring
App
3.7.2 Systems with direct functional earthing of the PV array
The inverter is not intended for functionally earthed PV arrays
3.7.3 Multiple inverter combinations
The inverter is not to be used in multiple inverter combinations.
3.7.4 Earth Fault Alarm
According to AS/NZS 5033, The alarm system shall continue repeating its operation at least at
hourly intervals until the earth fault is corrected or until the fault is acknowledged.
The earth fault alarm shall be at least one of the following types:
(a) Remote communication (such as email, SMS or similar).
(b) Local indication.
Where local indication is used for the earth fault alarm, it shall be either an audible or visual
signal placed in an area that will be noticed.
The ST Series inverter integrated earth fault alarm system, once an earth fault occurs, the LED
indicator will light up (red),
the inside buzzer will alarm at the same time. And the system will
email the fault information to the customer. Install the inverter in a high traffic area where the
indicators would be noticed.

Suzhou Stealth Energy Technology Co., Ltd.
17
4 Check and Storage
4.1 Check Before Receiving
Check the following items before receiving the product.
1.
Check the outer packing box for damage, such as holes, cracks, deformation, and other signs
of equipment damage. Do not unpack the contents from the box and contact the supplier as
soon as possible if any damage is found.
2.
Check the inverter model. If the inverter model is not what you requested, do not unpack the
product and contact the supplier.
3.
Check the deliverables for correct model, complete contents, and intact appearance. Contact
the supplier as soon as possible if any damage is found.
4.2 Delivery List
Inverter x1
Mounting plate x1
Expansion bolts x N
PV connectors x 2 pair
Battery connectors x 1 pair
AC Cover x 1
Meter x 1
Documents x 1
Screw x N
PE terminal x 1
Wi-Fi module x 1

Suzhou Stealth Energy Technology Co., Ltd.
18
WARNING
Connect the DC cables with the included terminals. The manufacturer shall not be liable for
the damage if other terminals are used.
4.3 Storage
If the equipment is not to be installed or used immediately, please ensure that the storage
environment meets the followingrequirements:
1.
Do not unpack the outer package or throw the desiccant away.
2.
Store the inverter in a dry place where ambient temperatures are -30°C…+70°C.
3.
The height and direction of the stacking inverters should follow the instructions on the
packing box.
4.
The inverters must be stacked with caution to prevent them from falling.
5.
If the inverter has been long term stored, it should be checked by professionals before being
put into use.
5 Installation Requirements
5.1 Installation Precautions
DANGER
Before Installing the inverter, make sure the inverter has no electrical connections. Before
drilling, make sure to avoid the water and electricity wiring in the wall to avoid danger !
CAUTION
Improper handling may result in personal injury! The instructions in the manual must be
followed when handling and placing the equipment. Poor ventilation in the Installation
environment will affect system performance!
• It is necessary to ensure good ventilation during the operation of the equipment.
• The device must be kept upright and the heat sink uncovered to ensure
adequate cooling inside the device.

Suzhou Stealth Energy Technology Co., Ltd.
19
5.2 Installation Location
• The inverter is IP65 rating and can be used for indoor or outdoor environment.
• Do not install the equipment in a place near flammable, explosive, or corrosive materials.
• The Installation wall must have the ability to support at least 4 times the weight of the inverter.
• The Installation location should be easy for electrical connection, operation and maintenance.
• Do not Install inverter in the living area.
• Do not Install inverter where children can reach it.
• The Installation environment must meet the following conditions:
Max. ambient
temperature
Min. ambient
temperature
Max. relative
humidity
Max. operating
altitude
• The Installation wall must have fire resistance, and there must be no flammable substances or
flammable gas in the Installation space.
Wall material flammability Flammable materials or gases are
found near the Installation point

Suzhou Stealth Energy Technology Co., Ltd.
20
• The installation height should facilitate the observation of LED indicators. Vertical installation for better
heat dissipation
• Do not install tilted, horizontally or upside down.
Forward lean Backward lean Flat Inverted
NOTICE
Inverter cannot be Installed horizontally, otherwise the equipment will be damaged.