Sungrow SG33CX User manual

SG33_40_50CX-UEN-Ver11-201907 Version: 1.1
User Manual
SG33CX
SG40CX
SG50CX
PV Grid-Connected Inverter

I
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.
Trademarks
and other Sungrow trademarks used in this manual are
owned by Sungrow Power Supply Co., Ltd.
All other trademarks or registered trademarks mentioned in this document 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.
Sungrow Power Supply Co., Ltd.
Address: No.1699 Xiyou Rd., New & High Tech Zone, Hefei, 230088, China.
Email: [e-mail]
Tel: [phone]
Website: www.sungrowpower.com

II
About This Manual
The manual mainly describes the product information, guidelines for installation,
operation and maintenance. The manual cannot include complete information
about the photovoltaic (PV) system. You can get additional information about
other devices at www.sungrowpower.com or on the webpage of the respective
component manufacturer.
Validity
This manual is valid for the following inverter types:
SG33CX
SG40CX
SG50CX
They will be referred to as “inverter” hereinafter unless otherwise specified.
Target Group
Plant owner
Installation engineer
Maintenance engineer
How to Use This Manual
Read the manual and other related documents before performing any work on
the inverter is carried out. Documents must be stored carefully and be available
at all times.
The contents of the manual will be periodically updated or revised due to the
product development. It is probably that there are changes of manual in the
subsequent inverter edition. The latest manual can be acquired via visiting the
website at www.sungrowpower.com.
Symbols
Important instructions contained in this manual should be followed during
installation, operation and maintenance of the inverter. They will be highlighted
by the following symbols.

III
Symbol
Explanation
Indicates a hazard with a high level of risk that, if not
avoided, will result in death or serious injury.
Indicates a hazard with a medium level of risk that, if not
avoided, could result in death or serious injury.
Indicates a hazard with a low level of risk that, if not
avoided, could result in minor or moderate injury.
Indicates a situation that, if not avoided, could result in
equipment or property damage.
Indicates additional information, emphasized contents or
tips that may be helpful, e.g. to help you solve problems or
save time.

IV
Contents
About This Manual....................................................................II
1Safety....................................................................................1
1.1 PV modules...............................................................................1
1.2 Utility Grid..................................................................................1
1.3 Inverter......................................................................................2
1.4 Skills of Qualified Personnel......................................................3
2Product Introduction...........................................................4
2.1 Intended Usage.........................................................................4
2.2 Product Introduction..................................................................5
2.2.1 Type Description........................................................................ 5
2.2.2 Appearance............................................................................... 6
2.2.3 Dimensions ...............................................................................7
2.2.4 LED Indicator Panel ..................................................................7
2.2.5 DC Switch .................................................................................8
2.3 Circuit Diagram..........................................................................8
2.4 Function Description..................................................................9
3Unpacking and Storage ....................................................11
3.1 Unpacking and Inspection....................................................... 11
3.2 Identifying the Inverter............................................................. 11
3.3 Scope of Delivery....................................................................13
3.4 Inverter Storage.......................................................................13
4Mechanical Mounting........................................................15
4.1 Safety during Mounting ...........................................................15
4.2 Location Selection...................................................................15
4.2.1 Installation Environment Requirements ................................... 16
4.2.2 Carrier Requirements .............................................................. 16
4.2.3 Installation Angle Requirements ..............................................16
4.2.4 Installation Clearance Requirements.......................................17

V
4.3 Installation Tools......................................................................18
4.4 Moving the Inverter..................................................................20
4.4.1 Manual Transport ....................................................................20
4.4.2 Hoisting Transport................................................................... 21
4.5 PV Bracket-Mounted Installation.............................................22
4.5.1 Preparation before Mounting................................................... 22
4.5.2 Mounting Steps........................................................................ 22
4.6 Wall-Mounted Installation........................................................24
4.6.1 Preparation before Mounting................................................... 24
4.6.2 Mounting Steps........................................................................25
5Electrical Connection .......................................................28
5.1 Safety Instructions...................................................................28
5.2 Terminal Description................................................................28
5.3 Electrical Connection Overview...............................................29
5.4 Additional Grounding Connection............................................31
5.4.1 Additional Grounding Requirements........................................31
5.4.2 Connection Procedure............................................................. 31
5.5 AC Cable Connection..............................................................32
5.5.1 AC Side Requirements............................................................32
5.5.2 Requirement for OT/DT Terminal.............................................34
5.5.3 Aluminium Cable Requirements ..............................................35
5.5.4 Connection Procedure............................................................. 35
5.6 PV String Connection..............................................................38
5.6.1 PV Input Configuration ............................................................38
5.6.2 Connection Procedure............................................................. 40
5.6.3 Installing the PV Connectors ................................................... 41
5.7 Communication Junction Box.................................................. 42
5.7.1 Remove the Junction Box........................................................42
5.7.2 Install the Junction Box............................................................ 42
5.8 Communication Wiring Board..................................................43
5.9 RS485 Communication ...........................................................43
5.9.1 Interface Description ...............................................................43
5.9.2 RS485 Communication System...............................................44

VI
5.9.3 Connection Procedure............................................................. 46
5.10 Dry Contact Connection ..........................................................50
5.10.1 Dry Contact Function.............................................................50
5.10.2 Wiring Procedure................................................................... 53
5.11 Communication Module Connection (optional)........................ 53
6Commission.......................................................................54
6.1 Inspection before Commissioning ...........................................54
6.2 Commissioning Procedure ......................................................54
7iSolarCloud APP................................................................55
7.1 Brief Introduction.....................................................................55
7.2 Download and Install...............................................................55
7.3 Menu.......................................................................................56
7.4 Login .......................................................................................56
7.4.1 Requirements..........................................................................56
7.4.2 Login Steps .............................................................................57
7.5 Home page.............................................................................. 58
7.6 Running Information................................................................60
7.7 History Record.........................................................................62
7.7.1 Fault Alarm Records................................................................ 62
7.7.2 Power Yields Records ............................................................. 63
7.7.3 Event Records......................................................................... 64
7.8 More........................................................................................64
7.8.1 Parameter Setting ................................................................... 65
7.8.2 Password Changing ................................................................65
8System Decommissioning ...............................................66
8.1 Disconnecting the Inverter.......................................................66
8.2 Dismantling the Inverter ..........................................................66
8.3 Disposal of the Inverter ...........................................................67
9Troubleshooting and Maintenance..................................68
9.1 Troubleshooting.......................................................................68
9.2 Maintenance............................................................................77
9.2.1 Routine Maintenance ..............................................................78

VII
9.2.2 Maintenance Instruction ..........................................................78
10 Appendix............................................................................81
10.1 Technical Data.........................................................................81
10.2 Quality Assurance ...................................................................83
10.3 Contact Information.................................................................84

1
1 Safety
The inverter has been designed and tested strictly according to international
safety regulations. Read all safety instructions carefully prior to any work and
observe them at all times when working on or with the inverter.
Incorrect operation or work may cause:
injury or death to the operator or a third party; or
damage to the inverter and other property safety of the operator or a third
party.
All detailed work-related safety warnings and notes will be specified at critical
points in this manual.
The safety instructions in this manual cannot cover all the precautions
that should be followed. Perform operations considering actual onsite
conditions.
SUNGROW shall not be held liable for any damage caused by
violation of the safety instructions in this manual.
1.1 PV modules
PV strings will produce electrical power when exposed to sunlight and can
cause a lethal voltage and an electric shock.
Always keep in mind that the inverter is dual power supplied. Electrical
operators must wear proper personal protective equipment: helmet,
insulated footwear, glove, etc.
Before touching the DC cables, operator must use a measuring device to
ensure that the cable is voltage-free.
Must follow all warnings on the PV strings and in its manual.
1.2 Utility Grid
Please follow the regulations related to the utility grid.

1 Safety User Manual
2
All electrical connections must be in accordance with local and national
standards.
Only with the permission of the utility grid, the inverter can be connected
to the utility grid.
1.3 Inverter
Danger to life from electric shocks due to live voltage
Do not open the enclosure at any time. Unauthorized opening will
void guarantee and warranty claims and in most cases terminate the
operating license.
Risk of inverter damage or personal injury
Do not pull out the PV connectors when the inverter is running.
Wait 5 minutes for the internal capacitors to discharge. Ensure that
there is no voltage or current before pulling any connector.
All safety instructions, warning labels, and nameplate on the inverter:
Must be clearly legible.
Should not be removed or covered.
Risk of burns due to hot components!
Do not touch any hot parts (such as heat sink) during operation. Only the
DC switch can safely be touched at any time.

User Manual 1 Safety
3
Only qualified personnel can perform the country setting.
Unauthorized alteration of the country setting may cause a breach of the
type-certificate marking.
Risk of inverter damage due to electrostatic discharge (ESD).
By touching the electronic components, you may damage the inverter. For
inverter handling, be sure to:
Avoid any unnecessary touching;
Wear a grounding wristband before touching any connectors.
Warning Label
Label
Description
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 service!
5 min
Do not touch live parts until 5minutes after disconnection
from the power sources.
There is a danger from a hot surface that may exceed
60°C.
Check the user manual before service!
1.4 Skills of Qualified Personnel
All installations should be performed by technical personnel. They should have:
Training in the installation and commissioning of the electrical system, as
well as the dealing with hazards
Knowledge of the manual and other related documents
Knowledge of the local regulations and directives

4
2 Product Introduction
2.1 Intended Usage
SG33CX, SG40CX, SG50CX, 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.
A B C D
E
Fig. 2-1 Inverter application in PV power system
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.
Item
Description
Note
A
PV strings
Monocrystalline silicon, polycrystalline silicon and
thin-film without grounding.
B
Inverter
SG33CX, SG40CX, SG50CX.
C
Grid
connection
cabinet
Includes devices such as AC circuit breaker, SPD,
metering device.
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

User Manual 2 Product Introduction
5
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 N PE
Inverter
L1 L2 L3 N PE
Inverter
L1 L2 L3 N PE
Inverter
L1 L2 L3 N PE
Inverter
L1 L2 L3 N PE
2.2 Product Introduction
2.2.1 Type Description
The device type description is as follows (Take SG33CX as an example):
SG 33 CX
Code of Product Series
Code Of power level
Photovoltaic grid-connected inverter
Tab. 2-1 Power Level Description
Type
Nominal Output Power
Nominal Grid Voltage
SG33CX
33000W
3 / N / PE，230 / 400V
SG40CX
40000W
SG50CX
50000W
The device type can be found on the nameplate attached to the side of the
inverter. For details, refer to Fig. 3-1Nameplate.

2 Product Introduction User Manual
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2.2.2 Appearance
1
2
4
6
7
8
3
5
*The image shown here is for reference only. The actual product you receive
may differ.
No.
Name
Description
1
LED indicator panel
HMI interface to indicate the present working state
of the inverter.
2
Mounting ears
4, used to hang the inverter onto the
mounting-bracket.
3
Side handles
2, used to move the inverter.
4
Labels
Warning symbols, nameplate, and QR code.
5
Additional
grounding terminals
2, use at least one of them to ground the inverter.
6
Bottom handles
2, used to move the inverter.
7
DC switches
To disconnect the DC current safely.
8
Wiring area
DC switches, AC terminals, DC terminals, and
communication terminals.
For details, refer to 5.2 Terminal Description

User Manual 2 Product Introduction
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2.2.3 Dimensions
Depth
Height
Width
Fig. 2-2 Dimensions of the Inverter
Type
Dimensions (W*H*D)
Weight
SG33CX
702×595×310mm
50 kg
SG40CX
782×645×310mm
58 kg
SG50CX
62kg
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.
Tab. 2-2 LED indicator description
LED indicator
LED state
Definition
Steady Blue
The device is connected to the grid and
operating normally.
Periodical flashing
blue (Period: 0.2s)
The Bluetooth communication is
connected and there is data
communication. No inverter fault occurs.
Periodical flashing
blue (Period: 2s)
The DC or AC side is powered on and the
device is in standby or startup state (not
feeding power into the gird).
Steady Red
A fault occurs and the device cannot
connect to the gird
Flashing Red
The Bluetooth communication is
connected and there is data
communication.Fault occurs.
OFF
Both the AC and DC sides are powered
down.

2 Product Introduction User Manual
8
2.2.5 DC Switch
The DC switch is used to disconnect the DC current safely whenever
necessary.
The SG33CX is equipped with one DC switch to control the connection and
disconnection of all DC terminals.
The SG40CX and SG50CX are equipped with two DC switches separately
controlling a group of DC inputs. The correspondence is as follows:
(SG40CX)(SG50CX)
2.3 Circuit Diagram
The MPPT is utilized for DC input to ensure the maximum power from the PV
array at different PV input conditions. The inversion circuit converts the DC
power intoAC power and feeds the AC power into the utility grid through the AC
terminal. The protection circuit is equipped to ensure the safe operation of the
device and personal safety.
Fig. 2-3 shows the main circuit of the inverter.
L1
PE
L2
L3
AC SPD
DC1
DC switch DC Bus Inverter Circuit
(DC/AC)
AC
Relays
DCn
Current
Monitoring
MPPT
(Boost 1)
DC EMI
Filter
DC SPD
N
*SG33/40/50CX: n= 3/4/5
MPPT
(Boost 2 )
AC
Filter
AC EMI
Filter
Fig. 2-3 Circuit diagram

User Manual 2 Product Introduction
9
2.4 Function Description
The inverter is equipped with the following functions:
Inversion function
The inverter converts the DC current into grid-compatible AC current and feeds
the AC current into the grid.
Data storage
The inverter stores the running information, fault records, etc.
Parameter Configuration
The inverter provides various parameter settings. You can set the parameters
via the phone’s APP to change the requirements of the device or optimize the
performance of the device.
Communication Interface
The inverter is designed with standard RS485 communication interfaces and
communication accessory port.
−The standard RS485 communication interfaces are used to establish
communication connection with monitoring devices and upload
monitoring data to background by using communication cables.
−The communication accessory port is used to connect communication
module manufactured by SUNGROW such as Eye and WiFi, and upload
monitoring data to background by means of wireless communication such
as Bluetooth, WiFi or wireless network.
The inverter can be connected to communication devices via either of the two
interfaces. After communication connection is established, users can view
inverter information or set inverter parameters through the iSolarCloud.
It is recommended to use the communication module produced by
SUNGROW, such as Eye, WiFi, or E-Net. A third-party
communication device may cause communication failure or even
unpredictable damage.
The RS485 communication interfaces and the communication
accessory port are not available at the same time. Otherwise,
communication failure or other problems can be caused.
Protection Function
The protective functions are integrated in the inverter, including anti-island
protection, LVRT/ZVRT, DC reversed polarity protection, AC short circuit
protection, leakage current protection, DC overvoltage/overcurrent protection,
etc.

2 Product Introduction User Manual
10
PID function
After the PID function is enabled, the voltage to ground of all PV modules is
greater than 0, that is, the PV module-to-ground voltage is a positive value.
PV moudle
Rise the to-ground electromotive force
at the negative pole of the PV moidle
Inverter Transformer Grid
Before enabling the PID recovery function, make sure the voltage
polarity of the PV modules to ground meets requirement. If there are
any questions, contact the PV module manufacturer or read its
corresponding user manual.
If the voltage scheme for the PID protection/recovery function does not
meet the requirement of corresponding PV modules, the PID function
will not work as expected or even damage the PV modules.
PID recovery function
When the inverter is not running, the PID module will apply inverse voltage to
PV modules, to restore the degraded modules.
If the PID recovery function is enabled, it only works at night.
After the PID recovery function is enabled, the voltage of the PV
string to ground is 500Vdc by default, and the default value can be
modified through the APP.