Sungrow SG250HX-US User manual

SG250HX-USPV
Grid-Connected InverterUser
ManualSG250HX-US-UEN-Ver17-
202202
PV Grid-Connected Inverter
User Manual
SG250HX-US
SG250HX-US-UEN-Ver17-202202

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All Rights Reserved
All Rights Reserved
No part of this document can be reproduced in any form or by any means without the prior
written permission of Sungrow Power Supply Co., Ltd (hereinafter "SUNGROW").
Trademarks
and other Sungrow trademarks used in this manual are owned by
SUNGROW.
All other trademarks or registered trademarks mentioned in this manual are owned by their
respective owners.
Software Licenses
• It is prohibited to use data contained in firmware or software developed by SUNGROW,
in part or in full, for commercial purposes by any means.
• It is prohibited to perform reverse engineering, cracking, or any other operations that
compromise the original program design of the software developed by SUNGROW.

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About This Manual
The manual mainly contains the product information, as well as guidelines for installation,
operation, and maintenance. The manual does not include complete information about the
photovoltaic (PV) system. Readers can get additional information at www.sungrowpower.
com or on the webpage of the respective component manufacturer.
Validity
This manual is valid for the following model of low-power grid-connected PV string inverters:
• SG250HX-US
It will be referred to as "inverter" hereinafter unless otherwise specified.
Target Group
This manual is intended for professional technicians who are responsible for installation, op-
eration, and maintenance of inverters, and users who need to check inverter parameters.
The inverter must only be installed by professional technicians. The professional technician
is required to meet the following requirements:
• Know electronic, electrical wiring and mechanical expertise, and be familiar with electri-
cal and mechanical schematics.
• Have received professional training related to the installation and commissioning of elec-
trical equipment.
• Be able to quickly respond to hazards or emergencies that occur during installation and
commissioning.
• Be familiar with local standards and relevant safety regulations of electrical systems.
• Read this manual thoroughly and understand the safety instructions related to
operations.
How to Use This Manual
Please read this manual carefully before using the product and keep it properly at a place
for easy access.
All contents, pictures, marks, and symbols in this manual are owned by SUNGROW. No part
of this document may be reprinted by the non-internal staff of SUNGROW without written
authorization.
Contents of this manual may be periodically updated or revised, and the actual product pur-
chased shall prevail. Users can obtain the latest manual from support.sungrowpower.com
or sales channels.
Symbols
This manual contains important safety instructions, which are highlighted with the following
symbols, to ensure personal and property safety during usage, or to help optimize the prod-
uct performance in an efficient way.
Please carefully understand the meaning of these warning symbols to better use the manual.

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Indicates high-risk potential hazards that, if not avoided, may lead to death or seri-
ous injury.
Indicates moderate-risk potential hazards that, if not avoided, may lead to death or
serious injury.
Indicates low-risk potential hazards that, if not avoided, may lead to minor or mod-
erate injury.
Indicates potential risks that, if not avoided, may lead to device malfunctions or fi-
nancial losses.
“NOTE” indicates additional information, emphasized contents or tips that may be
helpful, e.g., to help you solve problems or save time.

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Contents
All Rights Reserved .....................................................................................................I
About This Manual......................................................................................................II
1 Safety .................................................................................................................1
1.1 Unpacking and Inspection ...............................................................................1
1.2 Installation Safety ...........................................................................................1
1.3 Electrical Connection Safety............................................................................2
1.4 Operation Safety ............................................................................................3
1.5 Maintenance Safety........................................................................................4
1.6 Disposal Safety ..............................................................................................4
2 Product Description ..........................................................................................5
2.1 System Introduction........................................................................................5
2.2 Product Introduction........................................................................................6
2.3 Symbols on the Product ..................................................................................8
2.4 LED Indicator .................................................................................................8
2.5 Circuit Diagram ..............................................................................................9
2.6 Function Description .....................................................................................10
3 Unpacking and Storage .................................................................................13
3.1 Unpacking and Inspection .............................................................................13
3.2 Inverter Storage ...........................................................................................13
4 Mechanical Mounting .....................................................................................15
4.1 Safety during Mounting .................................................................................15
4.2 Location Requirements .................................................................................15
4.2.1 Environment Requirements..................................................................16
4.2.2 Carrier Requirements ..........................................................................16
4.2.3 Angle Requirements............................................................................17
4.2.4 Clearance Requirements .....................................................................17
4.3 Installation Tools...........................................................................................19
4.4 Moving the Inverter .......................................................................................20
4.4.1 Manual Transport................................................................................21
4.4.2 Hoisting Transport...............................................................................21
4.5 Installing the mounting-bracket ......................................................................22

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4.5.1 PV Bracket-Mounted Installation ..........................................................23
4.5.2 Wall-Mounted Installation.....................................................................24
4.6 Installing the Inverter.....................................................................................25
5 Electrical Connection .....................................................................................27
5.1 Safety Instructions........................................................................................27
5.2 Terminal Description .....................................................................................28
5.3 Electrical Connection Overview .....................................................................29
5.4 Crimp OT / DT terminal .................................................................................31
5.5 External Grounding Connection .....................................................................32
5.5.1 External Grounding Requirements........................................................33
5.5.2 Connection Procedure.........................................................................33
5.6 Opening the Wiring Compartment ..................................................................33
5.7 AC Cable Connection ...................................................................................34
5.7.1 AC-Side Requirements........................................................................34
5.7.2 Requirements for OT/DT Terminal ........................................................37
5.7.3 Connection Procedure.........................................................................37
5.8 DC Cable Connection ...................................................................................40
5.8.1 PV Input Configuration ........................................................................40
5.8.2 Assembling the PV Connectors ............................................................41
5.8.3 Installing the PV Connector..................................................................44
5.9 Wiring of Tracking System Power Cable (Optional) .........................................44
5.10 RS485 Connection......................................................................................47
5.10.1 Interface Description .........................................................................47
5.10.2 RS485 Communication System..........................................................48
5.10.3 Connection Procedure(Terminal Block) ...............................................50
5.11 PLC Communication Connection .................................................................52
5.12 Dry Contact Connection ..............................................................................52
5.12.1 Dry Contact Function.........................................................................52
5.12.2 Wiring Procedure ..............................................................................54
5.13 Closing the Wiring Compartment..................................................................54
6 Commissioning ...............................................................................................55
6.1 Inspection before Commissioning ..................................................................55
6.2 Commissioning Procedure ............................................................................55
7 iSolarCloud App ..............................................................................................57
7.1 Brief Introduction ..........................................................................................57
7.2 Installing the App..........................................................................................57

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7.3 Function Overview........................................................................................58
7.4 Login ...........................................................................................................58
7.4.1 Requirements .....................................................................................58
7.4.2 Login Procedure .................................................................................58
7.5 Home page ..................................................................................................61
7.6 Run Information............................................................................................63
7.7 Records.......................................................................................................65
7.8 More............................................................................................................67
7.8.1 System Parameters.............................................................................67
7.8.2 Operation Parameters .........................................................................68
7.8.3 Power Regulation Parameters..............................................................69
7.8.4 Communication Parameters.................................................................74
7.8.5 Firmware Update ................................................................................75
7.8.6 Password Changing ............................................................................77
8 System Decommissioning ............................................................................78
8.1 Disconnecting the Inverter.............................................................................78
8.2 Dismantling the Inverter ................................................................................78
8.3 Disposal of the Inverter .................................................................................79
9 Troubleshooting and Maintenance ..............................................................80
9.1 Troubleshooting ...........................................................................................80
9.2 Maintenance ................................................................................................88
9.2.1 Maintenance Notices...........................................................................88
9.2.2 Routine Maintenance ..........................................................................89
9.2.3 Cleaning Air Inlet and Outlet.................................................................89
9.2.4 Fan Maintenance ................................................................................89
10 Appendix .......................................................................................................92
10.1 Technical Data............................................................................................92
10.2 Wring Distance of DI Dry Contact.................................................................93
10.3 Quality Assurance ......................................................................................95
10.4 Contact Information ....................................................................................95

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1Safety
When installing, commissioning, operating, and maintaining the product, strictly observe the
labels on the product and the safety requirements in the manual. Incorrect operation or work
may cause:
• Injury or death to the operator or a third party;
• Damage to the product and other properties.
• The safety instructions in this manual are only supplements and cannot cover
all the precautions that should be followed. Perform operations considering ac-
tual onsite conditions.
• SUNGROW shall not be held liable for any damage caused by violation of gen-
eral safety operation requirements, general safety standards, or any safety in-
struction in this manual.
• When installing, operating, and maintaining the product, comply with local laws
and regulations. The safety precautions in this manual are only supplements
to local laws and regulations.
1.1 Unpacking and Inspection
Check all safety signs, warning labels and nameplates on devices.
Ensure that the safety signs, warning labels and nameplates must be clearly visible
and cannot be removed or covered before the device is decommissioned.
After receiving the product, check whether the appearance and structural parts of
the device are damaged, and check whether the packing list is consistent with the
actual ordered product. If there are problems with the above inspection items, do
not install the device and contact SUNGROW in time.
1.2 Installation Safety
Make sure there is no electrical connection before installation.
Before drilling, avoid the water and electricity wiring in the wall.

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Improper installation may cause personal injury!
• If the product supports hoisting transport and is hoisted by hoisting tools, no
one is allowed to stay under the product.
• When moving the product, be aware of the product weight and keep the balance
to prevent it from tilting or falling.
Before operating the product, must check and ensure that tools to be used have
been maintained regularly.
1.3 Electrical Connection Safety
Before electrical connections, please make sure that the inverter is not damaged,
otherwise it may cause danger!
Before electrical connections, please make sure that the inverter switch and all
switches connected to the inverter are set to "OFF", otherwise electric shock may
occur!
The PV string will generate lethal high voltage when exposed to sunlight.
• Operators must wear proper personal protective equipment during electrical
connections.
• Must ensure that cables are voltage-free with a measuring instrument before
touching DC cables.
• Respect all safety instructions listed in relevant documents about PV strings.
• The inverter must not be connected to a PV string that requires positive or neg-
ative grounding.
Danger to life due to a high voltage inside the inverter!
• Be sure to use special insulation tools during cable connections.
• Note and observe the warning labels on the product, and perform operations
strictly following the safety instructions.
• Respect all safety instructions listed in this manual and other pertinent
documents.
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Damage to the product caused by incorrect wiring is not covered by the warranty.
• Electrical connection must be performed by professionals.
• All cables used in the PV generation system must be firmly attached, properly
insulated, and adequately dimensioned.
Check the positive and negative polarity of the PV strings, and connect the PV con-
nectors to corresponding terminals only after ensuring polarity correctness.
During the installation and operation of the inverter, please ensure that the positive
or negative poles of PV strings do not short-circuit to the ground. Otherwise, an
AC or DC short-circuit may occur, resulting in equipment damage. The damage
caused by this is not covered by the warranty.
Comply with the safety instructions related to PV strings and the regulations re-
lated to the local grid.
1.4 Operation Safety
• When the inverter is running, do not touch its enclosure.
• When the inverter is running, it is strictly forbidden to plug and unplug any con-
nector on the inverter.
• When the inverter is running, do not touch any wiring terminal of the inverter.
Otherwise, electric shock may occur.
• When the inverter is running, do not disassemble any parts of the inverter. Oth-
erwise, electric shock may occur.
• When the inverter is running, it is strictly forbidden to touch any hot parts of the
inverter (such as the heat sink). Otherwise, it may cause burns.
• If the inverter is equipped with a DC switch, do not operate it when the inverter
is running. Otherwise, device damage or personal injury may occur.
User Manual 1 Safety

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1.5 Maintenance Safety
Risk of inverter damage or personal injury due to incorrect service!
• Before any service work, first disconnect the grid-side AC circuit breaker and
check the inverter status. If the inverter indicator is off, please wait until night to
disconnect the DC switch. If the inverter indicator is on, directly disconnect the
DC switch.
• After the inverter is powered off for 5 minutes, measure the voltage and current
with professional instrument. Only when there is no voltage nor current can op-
erators who wear protective equipment operate and maintain the inverter.
• Even if the inverter is shut down, it may still be hot and cause burns. Wear pro-
tective gloves before operating the inverter after it cools down.
Touching the power grid or the contact points and terminals on the inverter con-
nected to the power grid may lead to electric shock!
• The power grid side may generate voltage. Always use a standard voltmeter to
ensure that there is no voltage before touching.
To prevent misuse or accidents caused by unrelated personnel: Post prominent
warning signs or demarcate safety warning areas around the inverter to prevent
accidents caused by misuse.
To avoid the risk of electric shock, do not perform any other maintenance opera-
tions beyond this manual. If necessary, contact SUNGROW for maintenance. Oth-
erwise, the losses caused is not covered by the warranty.
1.6 Disposal Safety
Please scrap the inverter in accordance with relevant local regulations and stand-
ards to avoid property losses or casualties.
1 Safety User Manual

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2Product Description
2.1 System Introduction
The inverter is a transformerless 3-phase PV grid-connected inverter. As an integral compo-
nent in the PV power system, the inverter is designed to convert the direct current power
generated from the PV modules into grid-compatible AC current and to feed the AC current
into the utility grid.
The intended usage of the inverter is illustrated in the following figure.
figure 2-1 Inverter Application in PV Power System
The inverter must not be connected to a PV string that requires positive or negative
grounding.
Do not connect any local load between the inverter and the AC circuit breaker ex-
cept for the tracking axis.
The inverter applies only to the scenarios described in this manual.
Item Description Note
APV strings Monocrystalline silicon, polycrystalline silicon and thin-film
without grounding.
B Inverter SG250HX
C Transformer Boost the low voltage from the inverter to grid-compatible me-
dium voltage.
DUtility grid TN-C, TN-S, TN-C-S, TT, IT.
The following figure shows the common grid configurations.

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Make sure the inverter is applied to an IT system before enabling the Anti-PID
function.
2.2 Product Introduction
Model Description
The model description is as follows :
Appearance
The following figure shows the dimensions of the inverter. The image shown here is for refer-
ence only. The actual product received may differ.
2 Product Description User Manual

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figure 2-2 Inverter Appearance
No. Name Description
1 LED indicator To indicate the current working state of the inverter.
2 Labels Warning symbols, nameplate, and QR code.
3External ground-
ing terminals 2, use to ground the inverter.
4Bottom handles 2, used to move the inverter.
5Side handles 2, used to move the inverter.
6Mounting ears 4, used to hang the inverter onto the mounting-bracket.
7 DC Switch To safely disconnect the DC circuit whenever necessary.
8Wiring area DC terminals, and communication terminals.
For details, refer to “Terminal Description”
Dimensions
The following figure shows the dimensions of the inverter.
figure 2-3 Dimensions of the Inverter(in mm)
*The image shown here is for reference only. The actual product you receive may differ.
User Manual 2 Product Description

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2.3 Symbols on the Product
Symbol Explanation
Do not dispose of the inverter together with household waste.
CSA mark of conformity.
CE mark of conformity.
EU/EEA Importer.
Danger to life due to high voltages!
Only qualified personnel can open and service the inverter.
Disconnect the inverter from all the external power sources before
maintenance!
Burn danger due to the hot surface that may exceed 60°C.
Do not touch live parts for 5 minutes after disconnection from the power
sources.
Read the user manual before maintenance!
* The table shown here is for reference only. The actual product received may differ.
2.4 LED Indicator
The LED indicator on the front of the inverter indicates the working state of the inverter.
table 2-1 State description of the LED indicator
LED color State Definition
Blue
On The device is connected to the grid and operating
normally.
Fast blink
(Period: 0.2s)
The Bluetooth communication is connected and there
is data communication.
No system fault occurs.
Slow blink
(Period: 2s) The device is in standby or startup state (not feeding
power into the grid).
2 Product Description User Manual

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LED color State Definition
Slow blink
once, fast
blink three
times
The inverter is performing PID recovery.
Red
On A fault occurs and the device cannot connect to the
grid.
Twinkling The Bluetooth connection is established, data commu-
nication in process, and a system fault occurs.
Gray
OFF Both the AC and DC sides are powered down.
Voltage may still be present in AC side circuits after the indicator is off. Pay atten-
tion to the electricity safety during operating.
2.5 Circuit Diagram
The following figure shows the main circuit of the inverter.
figure 2-4 Circuit Diagram
• DC switches can safely disconnect the PV input when necessary to ensure the safe op-
eration of the inverter and the safety of personnel.
• The DC SPD provides a discharge circuit for the DC side over-voltage power to prevent
it from damaging the internal circuits of the inverter.
• EMI filters can filter out the electromagnetic interference inside the inverter to ensure that
the inverter meets the requirements of electromagnetic compatibility standards.
• The MPPT is utilized for DC input to ensure the maximum power from the PV array at dif-
ferent PV input conditions.
User Manual 2 Product Description

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• The inverter circuit converts the DC power into grid-compliant AC power and feeds it into
the grid.
• The AC filter filters the output AC component of high frequency to ensure that the output
current meets the grid requirements.
• The AC relay isolates the AC output of the inverter from the grid, making the inverter safe
from the grid in case of inverter failure or grid failure.
• The AC SPD provides a discharge circuit for the AC side over-voltage power to prevent it
from damaging the internal circuits of the inverter.
2.6 Function Description
The inverter is equipped with the following functions:
Conversion Function
The inverter converts the DC into grid-compatible AC and feeds the AC into the grid.
Data Storage and Display
The inverter logs system information like running information, error records, etc.
Parameter Configuration
The inverter provides various parameter configurations. Users can set parameters via the
App to meet different needs and optimize the inverter performance.
Communication Interface
The inverter is designed with standard RS485 communication interfaces.
The standard RS485 communication interfaces are used to establish communication with
monitoring devices and to upload monitoring data to a monitoring background through com-
munication cables.
When communication is established between the inverter and the communication devices,
users can view inverter information or set inverter parameters, such as running parameter
and protection parameter, through the iSolarCloud.
Protection Function
The inverter is equipped with anti-island protection, LVRT/HVRT, DC reversed polarity pro-
tection, AC short circuit protection, leakage current protection, DC over-voltage/over-current
protection, etc.
Potential Induced Degradation (PID)
The PID effect (Potential Induced Degradation) of PV modules will cause serious damage to
PV yield. Anti-PID function applies to the grid-connected operation of the inverter during the
day or the reactive power generation at night while the PID repair function applies to the off-
grid operation of the inverter at night.
Anti-PID function and PID repair function works differently when applied to P-type and N-
type panels.
• P-type panel
2 Product Description User Manual