Stealth ST-INV-S3.0 User manual

USER MANUAL
ST-INV-S3.0
ST-INV-S3.68
ST-INV-S4.0
ST-INV-S5.0
PV grid-connected energy
storage inverter
VER:1.2
www.stealthenergy.cn

User Manual
I
About this manual
This manual mainly introduces the product information, Installation, operation
and maintenance guidelines of the photovoltaic energy storage and grid-
connected integrated machine. It does not contain all the information of the
photovoltaic system. You can log on to www.stealthenergy.cn or the equipment
manufacturer's website for more information.
Scope of application
This manual is applicable to the following models of low-power string-type
photovoltaic energy storage grid-connected machines:
• ST-INV-S3.0
• ST-INV-S3.68
• ST-INV-S4.0
• ST-INV-S5.0
Unless otherwise speci󶀄ed, hereinafter referred to as inverter.
To the reader
This manual is inte nded for professional technicians who Install, operate and
maintain the inverter, as well as end users who need to view inverter information.
Manual use
Please read the manual carefully before using the product, and keep the manual
in a place where it is easily accessible.
The contents of the manual and the pictures, logos, symbols, etc. used are owned
by Suzhou Stealth Energy Technology Co., Ltd. Persons who are not inside the
company are not allowed to publicly reproduce all or part of the content without
written authorization.
The content of the manual will be continuously updated and revised, the user
please refer to the actual product purchased, and can pass the www.stealthenergy.
cn or sales channels to obtain the latest version of the manual.

User Manual
II
Change History
Changes between document issues are cumulative. The latest document
issuecontains all the changes made in earlier issues.
V1.2 (2023-02-20)
● Updated 9.2 Technical data .
PV Input :Max.input current(Ad.c.) and Max.short circuit current(Ad.c.)
V1.1 (2021-10-20)
This Version is the 󶎁rst o󶎃cial release.

User Manual
III
Symbol usage
In order to ensure the personal and property safety of users when using the
product, and to use the product more efficiently and optimally, the manual
provides relevant safety information, which is highlighted by the following
symbols.
Please carefully understand the meaning of the warning symbols so that you can
use the manual better.
Symbol Description


A highly potentially hazardous situation which, if not
avoided, will result in death or serious injury.
Moderately hazardous, which, if not avoided, could result in
death or serious injury.
！CAUTION
Low potential hazard situation which, if not avoided,could
result in moderate or minor injury to persons
There is a low potential hazard, and if not avoided, may
cause the equipment to fail to operate normally or cause
property damage.
Emphasizes and complements content, or provides tips
using the product that can help you solve a problem or
save time.
DANGER
WARNING
NOTICE

User Manual
IV
About this manual
1Safetyinstruction 1
1.1Generalsalfetyinstruction 1
1.2inverter 2
1.3Skillsrequirementsforprofessionalandtechnicalpersonnel 3
2Productdescription4
2.1Grid-connectedPVenergystoragesystem 4
2.2Poductintroduction 5
2.2.1Modeldescription 5
2.2.2Apperance 5
2.2.3Dimensionsandweight 6
2.2.4LEDindicatorlight 6
2.3Functiondescription 7
2.4Workingmode 8
3Unpackingandstorage11
3.1Unpackinginspection 11
3.2Identicationofinverter 11
3.3Deliverylist 12
3.4Storageofinverter 12
4MechanicalInstallation13
4.1InstalltionPrecautions 13
4.2ChoosetheInstallationsite 13
4.3Installationtoolsandparts 16
4.4Installationofinverter 17
5Electricalconnection19
5.1Terminalintroduction 20
5.2Overviewofelectricalconnection 21
5.3Groundconnection 22
5.4Gridandback-upconnection 23
5.4.1ACsiderequirements 23
5.4.2AssemblingthecabletotheAC&Back-upconnector 24
5.4.3InstallingtheACConnector 25
5.5PVseriesconnection 27
5.5.1PVInputConguration 27

User Manual
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5.5.2AssemblingthecabletothePVconnector 29
5.5.3InstallingthePVConnector 30
5.6Batterycableconnection 31
5.6.1Requirementsonthebatteryside 31
5.6.2AssemblingthecabletotheBatconnector 32
5.6.3InstallingtheBatConnector 33
5.7Type-Ccommunicationconnection 34
5.8MeterConnection 34
5.9DREDConnection 36
5.10BMSConnection 37
6Testoperation38
6.1Inspectionbaforetestrun 38
6.2Testrunsteps 38
7Decommissioning,dismantling,anddiscardingInverter39
7.1Decommissioning 39
7.2Dismantling 40
7.3Discarding 40
8Troubleshootingandmaintanance41
8.1Troubleshooting 41
8.1.1TroubleshootinginAPPdisplay 41
8.2Dailymaintanance 44
9Appendix45
9.1Contact 45
9.2Technicaldata 45
9.3QualityAssurance 48

User Manual
1
1 Safety instruction
Inverter machine is designed and tested in strict accordance with relevant
international safety standards. As electrical and electronic equipment, relevant
safety regulations must be observed during its Installation, commissioning,
operation and maintenance. Unreasonable use or misuse may result in:
• Harm the life and personal safety of the operator or a third party
• Damage the inverter or other property belonging to the operator/third party
In order to avoid personal injury, damage to the inverter or other equipment,
please strictly follow the following safety precautions. The specific precautions
during the operation will be explained in the corresponding chapters.
1.1 General salfety instruction
PV panels
Please follow the various instructions for photovoltaic panels.
Utility grid
Please follow the access of local grid.
All electrical connections must meet local and national electrical codes.
The inverter can only be connected to the grid with permission from the local
power department.
Fatal voltage dangerFatal voltage danger
Exposure of PV strings to sunlight will generate dangerous voltages.Exposure of PV strings to sunlight will generate dangerous voltages.
Since the energy storage battery system may cause the danger of electric shock Since the energy storage battery system may cause the danger of electric shock
and short circuit, in order to avoid possible accidents. All electrical connections and short circuit, in order to avoid possible accidents. All electrical connections
are required and should only be done by professional technicians.are required and should only be done by professional technicians.
DANGER
NOTICE

User Manual
2
1.2 inverter
The warning signs and descriptions on Inverter are shown in the table below:
Pay attention to danger, do not operate with electricity!
After the inverter unit is disconnected from all external power
sources, wait at least 5 minutes before touching live devices.
The surface is hot, be careful of burns! To avoid burns, do not
touch the surface of the machine while it is running.
High voltage danger!
Installation and operation should only be performed by
quali󶎁ed professionals.
Please read the manual before performing any operation on the
interver.
5min
The inverter can not be disposed together with the household
waste. Disposal information can be found in the enclosed
documentation.
CE mark.
The inverter complies with the requirements of the
applicable CE guidelines.
RCM remark.
TUV certi󶎁ed.

User Manual
3
Danger of electric shock!
Only the intact and closed box shell can protect the safety of people and
property. Do not open the cover of the inverter when the inverter is working or
powered on, otherwise Stealth Energy will not be held responsible.
Danger of damage to the inverter unit or personal injury!
When Inverter is working, it is forbidden to plug or unplug the PV connector, AC
connector and Bat connector.
All safety signs, warning labels and nameplates on the Inverter must be clearly
visible and cannot be removed or covered.
DANGER
WARNING
Danger of burns!
When the inverter is running, only touch the LED indicator and the DC switch. It
is strictly forbidden to touch the hot parts of the device (such as radiator, etc.)
during operation.
Country selection and protection parameters must be set by professional
technicians according to local power grid standards. The wrong country setting
may affect the normal operation of the inverter, causing the Inverter to be
inconsistent with the country's certi󶎁cation.
Touching printed circuit boards or other static-sensitive components may cause
damage to the device.
• Avoid unnecessary circuit board contact.
• Comply with electrostatic protection regulations and wear anti-static
wristbands.
！CAUTION
NOTICE
1.3 Skills requirements for professional and technical personnel
All Installation operations must and only be performed by professional
technicians. Professional technicians must:
• After special training;
• Read this manual completely and master the operation-related safety matters;
• Familiar with local standards and relevant safety regulations for electrical
systems.

User Manual
4
Ru n
Co m
R_ P
__
FN
Set
2 Product description
2.1Grid-connected PV energy storage system
ST-INV-S3.0,ST-INV-S3.68,ST-INV-S4.0 and ST-INV-S5.0 are single-phase
transformerless string photovoltaic energy storage inverters, which are an
important part of photovoltaic power generation systems. The inverter converts
the DC power generated by the photovoltaic panels into AC power that meets the
grid requirements to supply the load, and the rest charges the battery and feeds it
into the grid.
The inverter is only suitable for the energy storage grid-connected power
generation system described in this article.
Since the inverter is a transformerless type, it is required that the positive and
negative poles of the PV string cannot be grounded, otherwise the inverter will
not operate normally.
The battery system case needs to be grounded.
WARNING
The typical application scenarios of inverter are shown in the following 󶎁gure.
A
C
E
F
G
DCBreaker
≥ 40A*1
ACBreaker
On-Gridload
CT*2
Back-upload
ToSmartMeter
ToBatteryCable
ACBreaker
PE
1
2
35
4
Model 1 2 3 4 5
ST-INV-S3.0
40A/600V DC
Breaker
50A/230V AC Breaker 32A/230V AC Breaker
Depends on
household
loads
ST-INV-S3.68
ST-INV-S4.0
ST-INV-S5.0 63A/230V AC Breaker
1.For batteries with attached breaker, the external DC breaker is not necessary.
2.Direction of the CT cannot be connected in reverse, please follow House
(K) → Grid (L) direction to do the connection.
B
D

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Fig 2-1 Application of integrated machine in photovoltaic power generation
system
For TT-type grids, the neutral-to-ground voltage must be less than 30V.
Do not connect local loads, such as household appliances, lighting, and motor
loads, between the inverter and the AC circuit breaker.
NOTICE
2.2 Poduct introduction
2.2.1 Model description
For example,ST-INV-S5.0 ）：
ST - INV – S 5.0
5.0: Power class code
S: single phase
INV:Pv grid-connected inverter code
ST: Stealth
2-1 Power description
2.2.2 Apperance
The following illustrations are for reference only, please refer to the actual objects.
No. Item Description
A PV MonocryStealthine silicon, polycryStealthine silicon, thin-
󶎁lm batteries that do not need to be grounded.
B Inverter ST-INV-S5.0
CMetering device Standard metering tool for inverter output energy.
DGrid Grounding type: TT, TN.
EHousehold Loads Household appliances that consume electrical energy.
FImportant Loads Important Loads that cannot be suddenly cut o󶎀.
G Battery system Battery and BMS system components.
Model Nominal ouput Rated grid voltage
ST-INV-S3.0 3000VA
230Va.c.(single phase)
ST-INV-S3.68 3680VA
ST-INV-S4.0 4000VA
ST-INV-S5.0 4991VA

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2.2.3 Dimensions and weight
Figure 2-3 inverter size marking (unit：mm)
2.2.4 LED indicator light
As a human-machine interface, LED indicators are located on the front of the
Inverter. By observing the 󶎂ashing color and speed of the indicator light, the user
can obtain the current working status of the inverter. Please refer to Table 6-1 for
the description of indicator status.
Figure 2-4 LED indicator light
Figure 2-2 Apperance of ST-INV-S5.0
W
H
D
Model Width W (mm) Height H (mm) Depth D (mm) Net weight(kg)
ST-INV-S3.0
411 505 195 18.6
ST-INV-S3.68
ST-INV-S4.0
ST-INV-S5.0

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2.3 Function description
The functions of the fusioncube can be summarized as follows：
• Inverter function
The inverter converts direct current to alternating current consistent with the
requirements of the Installed regional grid and feeds it into the grid.
• Data storage
The Inverter stores system information, such as running information and fault
records.
• Parameter con󶎁guration
Inverter provides a variety of parameter con󶎁gurations to meet various needs or
to adjust its operating performance to the best. Users can view the information
of Inverter through the mobile app. For more professional configuration, please
contact Stealth after-sales.
• Communication interface
It can be connected to the WiFi communication data acquisition module to realize
the communication function and connect the monitoring equipment with the
entire photovoltaic energy storage system
• Protection function
Inverter has protection functions such as short-circuit protection, insulation
resistance grounding monitoring, residual current protection, anti-islanding
protection, and DC overvoltage/overcurrent protection.

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OperationModeIntroduction
NOTICE
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 Cloud 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:
MODE_ Ⅰ SelfUse
Theself-usemodeissuitableforareaswithlowfeed-in
subsidiesandhighelectricityprices.
①WhenthepowerofPVissucient
ActiveChargingorDischargetimeperiod:PVwillpowerthe
loadsrstly,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)
②WhenthepowerofPVisinsucient
ActiveChargingtimeperiod: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)
ActiveDischargetimeperiod: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)
STEALTH ST-INV-S3.0,ST-INV-S3.68,ST-INV-S4.0 and ST-INV-S5.0 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 su󶎃cient to meet the requirements, the battery should
be discharged to support the load consumption. If both photovoltaic power and
battery power are insu󶎃cient, the system will use grid power to support the load.
2.4 Working mode
1
2
3

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MODE_ Ⅱ Feed-in priority
TheFeed-inprioritymodeissuitableforareaswithhigh
feed-insubsidies,buthasfeed-inpowerlimitation.
① WhenthepowerofPVissucient
ActiveChargingtimeperiod:First,PVsupplypowertothe
load,thenchargethebatterytothesetcapacity,and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→Battery →Grid→Battery)
ActiveDischargetimeperiod:PVwillpowertheloadsrstly,
andsurpluspowerwillfeed-intothegrid.
(PV ＞ Load,PV→Load→Grid)
② WhenthepowerofPVisinsucient
ActiveChargingtimeperiod:PVwillpowertheloadsrstly,
theremainingpowerwillbetakenfromthegrid.Thebattery
willnotdischarge.
(PV ＜ Load,PV+Grid→Load)
Dischargetimeperiod: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)
③ WithoutPVpower
ActiveChargingtimeperiod:Thegridwillpowerthehome
loadsandalsochargethebattery;
(PV=0,Grid→Load+Battery)
ActiveDischargetimeperiod: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%
ChargebatterytominSOCcanbeset:10%-100%
1
2
③WithoutPVpower
ActiveChargingtimeperiod:Thegridsuppliestheloads
andalsocanchargethebattery;
(PV=0,Grid→Load+Battery)
ActiveDischargetimeperiod:Thebatterywillpowerthe
homeloadsörstly.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%
ChargebatterytominSOCcanbeset:10%-100%
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MODE_ ⅣEPS(O-grid)
TheEPS(O-grid)isusedwhenthepowergridiso.
SystemwillprovidesemergencypowerthroughPVand
batteriestosupplypowertothehouseholdloads.
(Batterymustbeinstalledforthismode)
① WhenthepowerofPVissucent
PVwillpowertheloadsrstly,andsurpluspowerwillcharge
tothebattery.
(PV ＞ Load,PV→Load→Battery)
② WhenthepowerofPVisinsucient
Theremainingpowerwillbetakenfromthebattery.
(PV ＜ Load,PV→Load)
③Without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(o-grid)SOC-minconditionisadjustablewithin
therangeof10%-25%;
MODE_ Ⅲ Backup mode
Theback-upmodeissuitableforareaswithfrequentpower
outages.
Sameworkinglogicwith“Self-use”mode.Thismodewill
maintainthebatterycapacityatarelativelyhighlevel.(Users'
setting)toensurethattheemergencyloadscanbeusedwhen
thegridiso.Customersnoneedtoworryaboutthebattery
capacity.
BatteryminSOCcanbeset:10%-100%.
ChargebatterytominSOCcanbeset:10%-100%.
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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 󶀄rst charge the
battery SOC15%, and then return to the working mode selected
by the user.

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3 Unpacking and storage
3.1 Unpacking inspection
Inverter has been completely tested and strictly inspected before leaving the
factory, but damage may still occur during transportation. Please conduct a
detailed inspection before signing for the product.
• Check the packing box for damage.
• According to the packing list, check whether the goods are complete and in
accordance with the order.
• Unpack and check whether the internal equipment is in good condition.
If you find any damage, please contact the shipping company or the after-sales
service of Stealth directly, and provide photos of the damage, so as to provide the
fastest and best service.
Do not discard the original packaging of Inverter. It is best to store Inverter in the
original box after it is out of service and removed.
3.2 Identi󶀄cation of inverter
The nameplate of inverter is attached to the side of the body.
Figure 3-2 inverter nameplate
Icon Description
Table 3-1 Description of nameplate
Conform to TÜV certi󶎁cate
Conform to CE certi󶎁cate
Refer to the relevant instructions
Do not dispose of inverter with household
waste
Pay attention to danger, do not
operate with electricity!
After the inverter unit is disconnected
from all external power sources, wait
at least 5 minutes before touching live
devices.
The surface is hot, be careful of burns! To
avoid burns, do not touch the surface of
the machine while it is running.
5min

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3.3 Delivery list
3-3 Delivery list
a)Unless otherwise speci󶎁ed, inverter diagrams in this document use ST-INV-S5.0
as an example.
b)Documentation includes quick user manual, certificate of conformity, packing
list and product test report.
c)The WiFi communication module may be standard or optional, subject to the
actual delivery.
3.4 Storage of inverter
If the inverter is not immediately put into operation, the inverter needs to be
stored in speci󶎁c environmental conditions:
• Repack in the original box, keep the desiccant.
• Storage temperature range -25 ℃ ~60 ℃ , relative humidity range 0~100%, no
condensation.
• The maximum number of stacked layers of multiple inverter machines does not
exceed 8 layers.
• The packing box cannot be tilted or inverted.

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4 Mechanical Installation
4.1 Installtion Precautions
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!
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 a󶎀ect 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.
4.2 Choose the Installation site
The inverter is IP65 rated and can be used for indoor Installation.
Choosing the best Installation location for an integrated machine plays a very
important role in its safe operation, life assurance, and performance assurance.
• 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. The operation of inverter generates
some noise, which may a󶎀ect daily life.
• Do not Install inverter where children can reach it.
• The Installation environment must meet the following conditions:
+60°C -25°C 100%
Max ambient temperature： Min ambient temperature： Max relative humidity:
！CAUTION

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• The Installation wall must have 󶎁re resistance, and there must be no 󶎂ammable
substances or 󶎂ammable gas in the Installation space.
• The installation height should facilitate the observation of LED indicators.
Vertical installation for better heat dissipation
• Do not install tilted, horizontally or upside down.
Wall material 󶎂ammability Flammable materials or gases are
found near the Installation point
Forward lean Backward lean 󶎂at Inverted
NOTICE
Inverter cannot be Installed horizontally, otherwise the equipment will be
damaged.