Sungrow SG125HV User manual

SG125HV-V1-UEN-Ver14-202002 Version: 1.4
User Manual
SG125HV
SG125HV-20
PV Grid-connected
Inverter

I
About This Manual
Validity
This manual is for the SG125HV/SG125HV-20, a three-phase PV
grid-connected transformerless inverter, (hereinafter referred to as inverter
unless otherwise specified). The inverter is grid-connected, transformer-less,
robust and of high conversion efficiency.
Aim
This manual contains information about the inverter, which will provide
guidelines on connecting the inverter into the PV power system and how to
operate the inverter.
Related Documents
The manual cannot include all information about the PV system. You may get
additional information at www.sungrowpower.com.
Target Group
This manual is for technical personnel who are responsible for inverter
installation, operation and maintenance, and the inverter owner who will
perform daily APP operation.
How to Use This Manual
Read the manual and other related documents before commencing any work
on the inverter. Documents must be stored carefully and available at all times.
All rights reserved including the pictures, markings and symbols used. Any
reproduction or disclosure, even partially, of the contents of this manual is
strictly prohibited without prior written authorization of SUNGROW.
The contents of the manual will be periodically updated or revised due to
product development. There may be changes in the manual due to subsequent
inverter editions. The latest manual can be acquired via visiting the website at
www.sungrowpower.com.
Symbols Explanation
Important instructions contained in this manual should be followed during
installation, operation and maintenance of the inverter. They will be highlighted

II
by the following symbols.
DANGER indicates a hazard with a high level of risk which, if not
avoided, will result in death or serious injury.
WARNING indicates a hazard with a medium level of risk which, if not
avoided, could result in death or serious injury.
CAUTION indicates a hazard with a low level of risk which, if not
avoided, could result in minor or moderate injury.
NOTICE indicates a situation which, if not avoided, could result in
equipment or property damage.
NOTE indicates additional information, emphasized contents or tips
to help you solve problems or save time.

III
Symbols on the Inverter Body
WARNING: ELECTRIC SHOCK HAZARD. THE DC
CONDUCTORS OF THIS PHOTOVOLTAIC SYSTEM ARE
UNGROUNDED AND MAY BE ENERGIZED.
WARNING: Electric Shock Hazard. The DC
conductors of this photovoltaic system are normally
ungrounded but will become intermittently grounded
without indication when the inverter measures the PV
array isolation.
CAUTION: Risk of Electric Shock, Do Not
Remove Cover. No User Serviceable Parts Inside. Refer
Servicing To Qualified Service Personnel.
CAUTION: Risk Of Electric Shock
a) Both ac and dc voltage sources are terminated inside
this equipment. Each circuit must be individually
disconnected before servicing, and
b) When the photovoltaic array is exposed to light, it
supplies a dc voltage to this equipment.
CAUTION: Risk of electric shock
from energy stored in capacitor. Do
not remove cover until 5 minutes after
disconnecting all sources of supply.
5 min
CAUTION: Hot surfaces –To reduce
the risk of burns. Do not touch.
CAUTION: Check user manual before
service!

IV
WARNING: ELECTRIC SHOCK HAZARD. THE DC CONDUCTORS OF THIS
PHOTOVOLTAIC SYSTEM ARE UNGROUNDED AND MAY BE ENERGIZED.
WARNING: Electric Shock Hazard. The DC conductors of this photovoltaic system
are normally ungrounded but will become intermittently grounded without indication
when the inverter measures the PV array isolation.
CAUTION: Risk of Electric Shock,Do Not Remove Cover. No User Serviceable Parts
Inside. Refer Servicing To Qualified Service Personnel.
CAUTION: Risk Of Electric Shock
a) Both AC and DC voltage sources are terminated inside this equipment. Each
circuit must be individually disconnected before servicing.
b) When the photovoltaic array is exposed to light, it supplies a DC voltage to this
equipment.
CAUTION: Risk of electric shock from energy stored in capacitor. Do not remove
cover until 5 minutes after disconnecting all sources of supply.
CAUTION：Hot surfaces –To reduce the risk of burns. Do not touch.
CAUTION: Check user manual before service.

V
Contents
About This Manual.....................................................................I
1Safety Instructions..............................................................1
2Product Description............................................................7
2.1 Intended Usage.........................................................................7
2.2 Product Introduction..................................................................8
2.2.1 Model Description......................................................................8
2.2.2 Appearance...............................................................................9
2.2.3 Dimensions .............................................................................10
2.2.4 LED Indicator Panel ................................................................10
2.2.5 DC Switch ............................................................................... 11
2.2.6 AC Switch................................................................................12
2.3 Technical Description ..............................................................12
2.3.1 Circuit Diagram........................................................................12
2.3.2 Function Description................................................................ 12
2.3.3 Derating...................................................................................13
2.3.4 PID Function ...........................................................................16
3Installation Flow................................................................17
4Unpacking and Storage....................................................19
4.1 Unpacking and Inspection.......................................................19
4.2 Identifying Inverter...................................................................19
4.3 Scope of Delivery....................................................................21
4.4 Inverter Storage.......................................................................21
5Mechanical Installation.....................................................23
5.1 Installation Site Selection........................................................ 23
5.2 Moving Inverter to Installation Site ..........................................27
5.3 Installation Tools...................................................................... 27
5.4 Installing the Inverter............................................................... 28
5.4.1 Installing to Metal Frame......................................................... 29

VI
5.4.2 Installing to Concrete Wall.......................................................30
6Electrical Connection .......................................................33
6.1 Terminal Description................................................................33
6.1.1 Appearance.............................................................................33
6.1.2 Dimensions of Terminal........................................................... 35
6.2 AC Side Cable Connection......................................................36
6.2.1 AC side requirements.............................................................. 36
6.2.2 Grid Connection ...................................................................... 39
6.2.3 Requirements for OT/DT Terminal (AC)................................... 41
6.2.4 Connecting the Inverter to Grid ...............................................41
6.3 Connecting Inverter to PV Arrays............................................44
6.3.1 PV Input Configuration ............................................................44
6.3.2 Requirements for OT/DT Terminal (DC) .................................. 45
6.3.3 PV Input Connection ...............................................................45
6.4 Additional Grounding Connection............................................48
6.4.1 Grounding System Overview...................................................48
6.4.2 Additional Grounding Terminal.................................................49
6.5 RS485 Communication Connection ........................................ 50
6.5.1 Communication Overview........................................................50
6.5.2 RS485 Communication System...............................................51
6.5.3 RS485 Communication Connection......................................... 53
6.6 Configurable Dry Contact........................................................54
7Commissioning .................................................................57
7.1 Inspection before Commissioning ...........................................57
7.2 Commissioning Procedure ......................................................57
8Disconnecting, Dismantling and Disposing the Inverter59
8.1 Disconnecting the Inverter.......................................................59
8.2 Dismantling the Inverter ..........................................................59
8.3 Disposal of the Inverter ...........................................................60
9Troubleshooting and Maintenance..................................61
9.1 Troubleshooting.......................................................................61
9.2 Maintenance............................................................................70

VII
9.2.1 Routine Maintenance ..............................................................70
9.2.2 Maintenance Instruction .......................................................... 71
10 iSolarCloud APP................................................................73
10.1 Brief Introduction.....................................................................73
10.2 Download and Install...............................................................73
10.3 Menu.......................................................................................74
10.4 Login .......................................................................................74
10.4.1 Requirements........................................................................ 74
10.4.2 Login Steps ........................................................................... 75
10.5 Home page.............................................................................. 76
10.6 Running Information................................................................78
10.7 History Record.........................................................................80
10.7.1 Fault Alarm Records..............................................................80
10.7.2 Yields Records ......................................................................81
10.7.3 Event Records.......................................................................82
10.8 More........................................................................................82
10.8.1 Power On/Power Off..............................................................83
10.8.2 System Parameters...............................................................83
10.8.3 Communication Parameters.................................................. 84
10.8.4 Operation Parameters...........................................................85
10.8.5 Protection Parameters...........................................................87
10.8.6 Password Changing .............................................................. 90
11 Appendix............................................................................92
11.1 Technical Data.........................................................................92
11.2Tightening Torques..................................................................93
11.3 Exclusion of Liability................................................................ 94
11.4 Contact Information.................................................................95

1
1 Safety Instructions
The inverter has been designed and tested according to strict international
safety regulations. As electrical and electronic equipment, safety instructions
related to them must be complied with during installation, commissioning,
operation and maintenance. Incorrect operation or work may result in damage
to:
The property safety of the operator or a third party
The inverter and other properties that belong to the operator or a third party
Therefore, the following general safety instructions must be read and always
kept in mind prior to any work. All detailed work-related safety warnings and
notes will be specified at the critical points in corresponding chapters.
All installations should be performed by technical personnel. They
should have:
Received professional training;
Read through this manual and understood all related safety
instructions;
Been familiar with electric system related safety instructions.
Technical personnel mentioned above may perform the following work:
Install the inverter in a proper place;
Connect the inverter to the PV system;
Connect other devices to the PV system;
Commission the inverter;
Operate and maintain the inverter.
Before Installation
The unit is thoroughly tested and strictly inspected before delivery.
Damage may still occur during shipping.
If there is visible damage to the packing case or the inner contents, or if
there is something missing, contact SUNGROW or the forwarding

1 Safety Instructions User Manual
2
company.
There is a risk of injury due to improperly handling the device!
Always follow the instructions in the manual when moving and
positioning the inverter.
Injuries, serious wounds, or bruises may occur if the device is
improperly handled.
During Mechanical Installation
Make sure inverter is not electrically connected before installing the
inverter.
System performance loss due to bad ventilation!
Proper-ventilation should be maintained during device operation. The
fan’s air inlet and outlet should not be covered to ensure the device
interior can sufficiently cool down.
During Electrical Connection
All electrical connections must be in accordance with national and
local standards.
The connection to the grid can be done only after receiving approval
from the local utility grid company.
Lethal voltage exists!
PV arrays will generate electrical energy when exposed to sunlight and thus
can create potential electrical shock hazards.
All cables must be firmly attached, undamaged, properly insulated and

User Manual 1 Safety Instructions
3
adequately dimensioned.
During Inverter Operation
Do not open inverter enclosure when inverter is under load or
operating.
Only an intact and locked inverter cabinet can ensure personal and
property safety.
There is a risk of burn!
Do not touch hot components of the inverter (for example, the
heatsink) during operation. Only the DC/AC switch can be touched
during operation.
Operate the inverter by strictly following the descriptions in this manual to avoid
unnecessary personal injury and property damage. Arc flash, fire or explosion
may occur if done otherwise and SUNGROW will hold no liability for damages.
The following improper operations can cause an arc flash, fire and
explosion inside the device. Keep in mind that these accidents can
only be handled by qualified personnel. Improper handling of these
accidents may lead to a more serious fault or accident.
Plugging in and unplugging the DC side HV fuse when it is alive;
Touching the end of the cables that have no insulation and may still
be alive;
Touching the connection copper bus bar, terminal or other spare
parts inside the device that may be alive;
The power cable connection is loose;
Spare parts, such as bolts, are falling inside the inverter;
Incorrect operation by unqualified persons that have not received
training;
Before any operation of the device, a preliminary arc flash assessment
in the operation area is necessary. If there is a possibility of an arc
flash,

1 Safety Instructions User Manual
4
The operators must receive related safety training;
Use best practices to assess the areas that may be affected by an
arc flash ;
Before any operation in the area that may be affected by an arc flash,
personal protective equipment (PPE) that meets the requirement
must be worn. APPE category 2 is recommended.
Maintenance and Service
There is a risk of inverter damage or personal injury due to incorrect
service work!
Before any operation, you should perform the following steps:
First, disconnect the grid side switch and then disconnect the DC
switch;
Wait at least 10 minutes until the inner capacitors are discharged
completely;
Verify, using proper testing device to make sure there is no voltage or
current.
Keep unqualified persons away!
A temporary warning sign and barrier must be posted to keep
unqualified persons away during electrical connection and
maintenance.
Restart the inverter only when the fault that may impair the inverter
safety functions is removed.
Inverter contains no owner serviceable parts inside. Please contact
local authorized personnel if any service work is required.
Do not replace the inverter internal components without permission.
Damage to the inverter may occur and it may void any or all warranty
rights from SUNGROW.

User Manual 1 Safety Instructions
5
There is a risk of inverter damage due to electrostatic discharge!
The printed circuit boards contain components sensitive to
electrostatic discharge.
Wear a grounding wrist band when handling the boards.
Avoid unnecessary touching of the boards.
Others
Certain parameter settings (country selection, etc.) by the iSolarCloud
APP must only be done by qualified persons.
Incorrect country setting may affect the inverter normal operation and
cause a breach of the type-certificate marking.
All safety instructions, warning labels, and nameplate on the inverter:
Must be clearly visible;
Should not be removed or covered.
Respect the following regulations:
Grid-connection regulations;
Safety instructions related to PV arrays;
Safety instructions related to other electrical devices.
WARNING: ELECTRIC SHOCK HAZARD. THE DC CONDUCTORS OF THIS
PHOTOVOLTAIC SYSTEM ARE UNGROUNDED AND MAY BE ENERGIZED.
WARNING: Electric Shock Hazard. The DC conductors of this photovoltaic system
are normally ungrounded but will become intermittently grounded without indication
when the inverter measures the PV array isolation.
CAUTION: Risk of Electric Shock, Do Not Remove Cover. No User Serviceable
Parts Inside. Refer Servicing To Qualified Service Personnel.
CAUTION: Risk Of Electric Shock

1 Safety Instructions User Manual
6
a) Both AC and DC voltage sources are terminated inside this equipment. Each
circuit must be individually disconnected before servicing, and
b) When the photovoltaic array is exposed to light, it supplies a DC voltage to this
equipment.
CAUTION: Risk of electric shock from energy stored in the capacitor. Do not remove
cover until 5 minutes after disconnecting all sources of supply.
CAUTION：Hot surfaces –To reduce the risk of burns. Do not touch.
CAUTION: Check user manual before service.

7
2 Product Description
2.1 Intended Usage
SG125HV/SG125HV-20; a transformerless three-phase PV grid-connected
inverter, is an integral component 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 feeds the AC current to the
utility grid. The intended usage of the inverter is illustrated in Fig. 2-1.
Inverter cannot connect the PV strings whose positive and negative
terminals need to be grounded.
Do not connect any local load between the inverter and the AC circuit
breaker.
Inverter is applicable only to the grid-connected PV system. Any other
usage is strictly forbidden.
B C D E A
Fig. 2-1 Inverter application in PV power system
Item
Description
Note
A
PV strings
Monocrystalline silicon, polycrystalline silicon, and
thin-film without grounding
B
Combiner Box
Combine the DC current of several PV string inputs
C
Inverter
SG125HV/SG125HV-20
D
Transformer
Boost the low voltage from inverter to grid-compatible
medium voltage.
E
Utility grid
TN-C, TN-S, TN-C-S, TT, IT
The following figure shows the common grid configurations.

2 Product Description User Manual
8
L2
PEN
L1
L3
TN-C
Transformer Transformer
L2
N
PE
L1
L3
TN-C-S
Inverter
L2
N
L1
L3
TT
Transformer
L2
N
PE
L1
L3
TN-S
Transformer
L2
L1
L3
IT
Transformer
L1 L2 L3 PE
Inverter
L1 L2 L3 PE
Inverter
L1 L2 L3 PE
Inverter
L1 L2 L3 PE
Inverter
L1 L2 L3 PE
If the Anti-PID function is to be enabled, ensure that:
The inverter is applied in the IT system.
The downstream transformer meets the requirements described in
6.2.1 Medium-voltage Transformers.
TheAC cables meet the requirements described in 6.2.2 AC Cable
Requirements.
2.2 Product Introduction
2.2.1 Model Description
The model description is as follows:
A CB
SG 125 HV
D
20-
A: Code of PV grid-connected inverter
B: Code of power level
C: High voltage input (1500Vdc)
D: Code of product version

User Manual 2 Product Description
9
Tab. 2-1 Version difference
2.2.2 Appearance
7
8
2
5
4
1
6
3
10
9
Fig. 2-2 Appearance
* Pictures are indicative only. Product in kind prevail.
No.
Name
Description
1
LED indicator panel
HMI interface to indicate the present working
state of the inverter.
2
DC switch
Protective components to safely disconnect DC
side current.
3
Waterproof air valve
-
4
Electrical connection
area
Includes DC terminal, AC terminal and RS485
communication terminal.
5
Air outlet
Controlled forced-air cooling method. Ensures
proper ventilation.
6
Handles
Handles are designed for transporting, installing
and disassembling the inverter
7
Cover plate of the
fan
The fan is located on the back of the cover plate
and used for the forced cooling of the inverter
8
AC switch
Serviced as an automatic overcurrent device
9
PE second terminal
User can connect this terminal as per
requirements.
10
Mounting ear
Hang the inverter on the bracket.
Model
PID function
Night SVG function
SG125HV
Optional
No
SG125HV-20
Yes
Yes

2 Product Description User Manual
10
2.2.3 Dimensions
296mm
(11.7inch)
902mm(35.5inch)
670mm(26.4inch)
832mm(32.8inch)
Fig. 2-3 Dimensions of the inverter
2.2.4 LED Indicator Panel
As an HMI, the LED indicator panel on the inverter front panel indicates the
present working state of the inverter.
Fig. 2-4 LED indicator panel
Tab. 2-2 LED indicator description
LED indicator
LED color
LED state
Definition
Bluetooth
Blue
ON
The Bluetooth communication is