KEHUA TECH SPI-B X2 Series User manual

PV Grid-tied Inverter
SPI-B X2 Series (8K-25K)
User Manual

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Copyright © Xiamen Kehua Digital Energy Tech Co., Ltd. 2022. All rights reserved.
No part of this document may be reproduced or transmitted in any form or by any means without prior
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All other trademarks and trade names mentioned in this document are the property of their respective
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Notice
The purchased products, services and features are stipulated by the contract made between Kehua and
the customer. All or part of the products, services and features described in this document may not be
within the purchase scope or the usage scope. Unless otherwise specification in the contract, all
statements, information, and recommendations in this document are provided “AS IS”without warranties,
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The information in this document is subject to change without notice. Every effort has been made in the
preparation of this document to ensure accuracy of the contents, but all statements, information, and
recommendations in this document do not constitute a warranty of any kind, express or implied.
XIAMEN KEHUA DIGITAL ENERGY TECH CO., LTD.
Address:
No.457,MalongRoad,TorchHigh-TechIndustrialZone,Xiamen,Fujian,China
Website:
www.kehua.com
E-mail:
[email protected]
Customer Service Telephone:
400-808-9986
Tel:
0592-5160516
Fax:
0592-5162166

Foreword
PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
ii
All rights reserved ©Xiamen Kehua Digital Energy Tech Co., Ltd.
Foreword
Summaries
Thank you for choosing the PV grid-tied inverter (hereinafter referred to as inverter)!
This document gives a description of the inverter, including appearance, features, working principles,
installation, electrical connection, operation, maintenance and storage, etc.
Please save the manual after reading, in order to consult in the future.
The figures in this manual are just for reference, for details please see the actual product.
Applicable Model
SPI8K-B X2
SPI10K-B X2
SPI12K-B X2
SPI15K-B X2
SPI17K-B X2
SPI20K-B X2
SPI23K-B X2
SPI25K-B X2
SPI25K-B X2P
Symbol Conventions
The manual quotes the safety symbols, these symbols used to prompt users to comply with safety
matters during installation, operation and maintenance. Safety symbol meaning as follows.

PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
Foreword
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iii
Symbol
Description
Alerts you to a high risk hazard that will, if not avoided, result in
serious injury or death.
Alerts you to a medium low risk hazard that could, if not avoided,
result in moderate or minor injury.
Alerts you to a low risk hazard that could, if not avoided, result in
minor injury.
Anti-static prompting.
Be care electric shock prompting.
Provides a tip that may help you solve a problem or save time.
Provides additional information to emphasize or supplement
important points in the main text.
Product standard: Q/XMHS 003

Contents
PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
iv
All rights reserved ©Xiamen Kehua Digital Energy Tech Co., Ltd.
Contents
1 Safety Description.........................................................................................................................1
1.1 Safety Announcements.....................................................................................................................................1
1.1.1 Use Announcements................................................................................................................................1
1.1.2 PV String Protection ...............................................................................................................................2
1.1.3 ESD Protection........................................................................................................................................3
1.1.4 Grounding Requirements........................................................................................................................3
1.1.5 Moistureproof Protection........................................................................................................................3
1.1.6 Warning Mark Setting.............................................................................................................................4
1.1.7 Electrical Connection..............................................................................................................................4
1.1.8 Measurement Under Operation...............................................................................................................4
1.2 Operator Requirements ....................................................................................................................................5
1.3 Operation Environment Requirements.............................................................................................................5
2 Overview.........................................................................................................................................6
2.1 Product Intro.....................................................................................................................................................6
2.1.1 Model Meaning.......................................................................................................................................7
2.1.2 Features...................................................................................................................................................7
2.2 Apperance and Structure ..................................................................................................................................8
2.2.1 LED Indicator .........................................................................................................................................8
2.2.2 External Terminal Illustration .................................................................................................................9
2.3 Working Principle...........................................................................................................................................10
3 Installation....................................................................................................................................11
3.1 Installation Process......................................................................................................................................... 11
3.2 Installation Preparation .................................................................................................................................. 11
3.2.1 Installation Tools................................................................................................................................... 11

PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
Contents
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3.2.2 Installation Environment.......................................................................................................................12
3.2.3 Installation Clearance............................................................................................................................13
3.2.4 Installation Method...............................................................................................................................14
3.3 Transportation and Unpacking .......................................................................................................................14
3.3.1 Transportation.......................................................................................................................................14
3.3.2 Unpacking and Checking......................................................................................................................14
3.4 Inverter Installation........................................................................................................................................15
3.5 Electrical Connection.....................................................................................................................................19
3.5.1 Wire Requirements................................................................................................................................19
3.5.2 External Grounding Connection ...........................................................................................................19
3.5.3 PV String Input Wiring.........................................................................................................................21
3.5.4 AC Output Wiring.................................................................................................................................24
3.5.5 WIFI/4G Communication Connection..................................................................................................27
3.5.6 COM. Communication Connection (Optional).....................................................................................28
3.6 Check the Installation.....................................................................................................................................31
4 Startup and Shutdown ...............................................................................................................32
4.1 Check Before Startup.....................................................................................................................................32
4.2 Start Inverter...................................................................................................................................................32
4.3 Shut Down Inverter........................................................................................................................................33
5 Maintenance and Troubleshooting .........................................................................................34
5.1 Maintenance...................................................................................................................................................34
5.1.1 Inverter Maintenance ............................................................................................................................34
5.1.2 Fan Maintenance...................................................................................................................................35
5.2 Troubleshooting..............................................................................................................................................36
6 Stop Running, Dismantle, Discard Inverter..........................................................................39
6.1 Stop Running..................................................................................................................................................39
6.2 Dismantle the Inverter....................................................................................................................................40
6.3 Discard the Inverter........................................................................................................................................40
7 Package, Transportation, Storage.............................................................................................41

Contents
PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
vi
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7.1 Package ..........................................................................................................................................................41
7.2 Transportation ................................................................................................................................................41
7.3 Storage ...........................................................................................................................................................41
A Technical Specifications ...........................................................................................................42
B Acronyms and Abbreviations ..................................................................................................48

PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
1 Safety Description
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1
1 Safety Description
This chapter mainly introduces the safety announcements. Prior to performing any work on the
device, please read the user manual carefully, follow the operation and installation instructions and
observe all danger, warning and safety information.
1.1 Safety Announcements
This section mainly describes the safety announcements when operation and maintenance. For details,
please refer to safety description in relevant chapters.
Before operation, please read the announcements and operation instructions in this section carefully
to avoid accident.
The promptings in the user manual, such as "Danger", "Warning", "Caution", etc. don't include all
safety announcements. They are just only the supplement of safety announcements when operation.
Any device damage caused by violating the general safety operation requirements or safety standards
of design, production, and usage will be out of Kehua's guarantee range.
1.1.1 Use Announcements
Don't touch terminals or conductors that connected with grid to avoid lethal risk!

1 Safety Description
PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
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There is no operational part inside the inverter. Please do not open the crust of the inverter by
yourself, or it may cause electric shock. The device damage caused by illegal operation is out of the
guarantee range.
After disconnect the input and output of the inverter, there still has residual energy in the storage
capacitor, which may cause electric shock. Do not perform the maintenance until all power sources
are switched off for 20 minutes and check that there is no voltage and current in the inverter by the
detection equipment.
The surface temperature of the inverter may reach to 75℃. During running, please don't touch the
surface to avoid scald.
No liquid or other objects are allowed to enter the inverter, or, it may cause inverter damage.
In case of fire, please use dry power fire extinguisher. If using liquid fire extinguisher, it may cause
electric shock.
1.1.2 PV String Protection
When install PV string in daytime, it necessary to cover the PV string by light-proof material, or the
PV string will generate high voltage under sunshine. If touching PV string accidently, it may cause
electric shock or human injury!

PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
1 Safety Description
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There exists dangerous voltage between the positive and negative of PV string!
When installing the device, make sure that the connection between inverter and PV string has been
disconnected completely. And set warning mark in the disconnected position to avoid reconnecting.
1.1.3 ESD Protection
To prevent human electrostatic damaging sensitive components(such as circuit board), make sure that
you wear a anti-static wrist strap before touching sensitive components, and the other end is well
grounded.
1.1.4 Grounding Requirements
High leakage risk! The inverter must be grounded before wiring. The grounding terminal must be
connected to ground, or, there will be the risk of electric shock when touching the inverter.
When installing, the inverter must be grounded first. When dismantling, the grounding wire must
be removed at last.
Don't damage the grounding conductor.
The inverter must be connected to protection grounding permanently. Before operation, check the
electrical connection to ensure the inverter is grounded reliably.
1.1.5 Moistureproof Protection
Moisture invasion may cause inverter damage!
Observe the following items to ensure the inverter works normally.

1 Safety Description
PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
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When the air humidity is more than 95%, don't open the door of the inverter.
In the wet or damp weather, don't open the door of the inverter to maintain or repair.
1.1.6 Warning Mark Setting
In order to avoid accident for unwanted person gets close to the inverter or makes improper operation,
observe the following requirements while installing, maintaining or repairing.
Set warning marks where the switches are to avoid switching them on improperly.
Set warning signs or safety warning belt in the operation area, which is to avoid human injury or
device damage.
1.1.7 Electrical Connection
Electrical connection must be performed according to the description in the user manual and the
electrical schematic diagram.
The configuration of PV string, grid level, grid frequency, etc. must meet the technical requirements
of inverter.
Grid-tied generation should be allowed by the local power supply department and the related
operation should be performed by professionals.
All electrical connection must meet the related country and district standard.
1.1.8 Measurement Under Operation
There exists high voltage in the device. If touching device accidently, it may cause electric shock. So,
when perform measurement under operation, it must take protection measure (such as wear insulated
gloves, etc.)
The measuring device must meet the following requirements:
The range and operation requirements of measuring device meets the site requirements.
The connections for measuring device should be correct and standard to avoid arcing.

PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
1 Safety Description
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1.2 Operator Requirements
The operation and wiring for inverter should be performed by qualified person, which is to ensure
that the electrical connection meets the related standards.
The professional technicist must be trained strictly, understand all safety announcements, master
correct operations and meet the following requirements:
Fully familiar with the structure and working principle of the whole PV grid-tied generation
system.
Know well about the related standards of local country and district.
1.3 Operation Environment Requirements
Avoid the inverter suffering directly sunshine, rain or snow to prolong the service life (detail please
see 3.2.2 ). If the installation environment does not meet the requirement, the service life may be
influenced.
The operation environment may influence the life span and reliability of device. So, please avoid to
use device in following environment:
The place where temperature and humidity beyond the technical specifications (temperature:
-35℃～60℃; relative humidity: 0%-95%).
The place with direct sunshine or rain.
The place with vibration or impact.
The place with dust, corrosive material, salt or burnable gas.
The place with poor ventilation or closed situation.
The place where close to resident living quarter.

2 Overview
PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
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2 Overview
This chapter mainly introduces product appearance, structure, working principles and grid form, etc.
2.1 Product Intro
The inverter converts the DC energy from PV string into AC energy and then feedbacks to power grid,
which is suitable for the commercial roof grid-tied system and large power station grid-tied system.
The PV grid-tied generation system consists of PV string, PV grid-tied inverter and grid , as shown in
Figure2-1.
PV grid-tied
inverter GridPV string
Figure2-1 PV grid-tied generation system
The inverter supports four grid forms, that is TN-S, TN-C, TN-C-S and TT, as shown in Figure2-2.
L1
L2
L3
N
PE
Inverter
Transformer
TN-S
L1
L2
L3
PE/N
Inverter
Transformer
TN-C
PE PE
L1
L2
L3
N
Inverter
Transformer
TT
PE
L1
L2
L3
N
PE
Inverter
Transformer
TN-C-S
PE
Figure2-2 Grid form

PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
2 Overview
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For type TT grid, the effective value of neutral and grounding voltage must be less than 20V.
2.1.1 Model Meaning
The model meaning of SPI-B X2 series (8K-25K) is as shown in Figure2-3.
SPI □K-B X2
SPI series PV grid-tied inverter
Rated output power
When it is 20, it means the rated output power is 20kW;
When it is 25, it means the rated output power is 25kW;
And so on.
Isolation type
Second generation
When it is X2P, it means the inverter can be equipped
with large current PV string.
Figure2-3 Model meaning
2.1.2 Features
Efficiently power generation: adopt high-efficiency type-T three-level high-frequency conversion
technology and advanced completely digitized control technology, wide work range of MPPT
and high power generation efficiency.
Safe and reliable: adopt aluminium alloy to diecast the outer case, so that the inverter can work in
a widely temperature range. The degree of protection is IP66 and it adopts whole industrial grade
electron device.
Smart manage: adopt smart cloud platform monitor andAPP real-time monitor. The inverter
supports RS485, WIFI and 4G communication, can connect with DRM and smart meter, and with
anti-backflow function. Besides, it can be updated and set the parameters remotely.
Green and friendly: small size, easy installation and use.
Better adaptability: with better grid adaptability, wide reactive power adjusting range.

2 Overview
PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
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2.2 Apperance and Structure
The appearance of SPI-B X2 series (8K-25K) is as shown in Figure2-4.
Figure2-4 Appearance
2.2.1 LED Indicator
The LED indicator on the front panel of inverter shows the inverter status, as shown in Table2-1.
Table2-1 LED indicator status illustration
Indicator
Status
Meaning
Green indicator is on.
Inverter running.
Green indicator flashes.
Inverter standby.
Green indicator and red
indicator flash alternately.
Inverter fault (not off-grid)
Red indicator is on.
Inverter fault (off-grid)
Red indicator flashes.
DC has no input.
Indicator is off.
AC and DC are powered off.

PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
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2 Overview
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2.2.2 External Terminal Illustration
The external terminals are all located at the bottom of the inverter, including PV input, AC output,
DC switch and communication interface, etc. as shown in Figure2-5.
Figure2-5 Bottom layout
Table2-2 Bottom layout illustration
NO.
Mark
Name
Remarks
○
1
B+/B-
Energy storage interface (reserved)
Connect battery.
○
2
DC SWITCH
DC switch
DC switch connects inverter with
PV string.
○
3
PV+/PV-
PV string terminal
Connect PV string.
○
4
COM.
DRM (optional) /RS485 interface
Connect DRM/RS485 wire.
○
5
WIFI/4G
WIFI (optional) /4G interface
Connect WIFI/4G stick.
○
6
AC OUTPUT
AC output wiring hole
Connect AC output wire.
○
7
External grounding terminal
Connect external grounding wire.
When the communication function is not selected, the corresponding port is blocked with a waterproof
plug.

2 Overview
PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
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DC Switch
The DC switch (as shown in the ○ 2 of Figure2-5) connects inverter with the PV string.
When the inverter works normally, the DC switch must be ON.
When installation and wiring, the DC switch must be OFF.
Before maintenance, the DC switch must be OFF for 20 minutes, and measure the voltage of
inner DC busbar by multimeter, only when the voltage is less than 10V, the maintenance can be
done.
When maintenance or wiring, the DC switch must be disconnected.
2.3 Working Principle
PV strings are connected to inverter, and do the max. power point tracking for PV strings through the
two-groups of MPPT circuits inside inverter, and then convert the DC power into the three-phase AC
power through the inverter circuit. It also provides surge protection in DC and AC side, as shown in
Figure2-6.
-
+
MPPT1
-
+U
V
W
DC/AC
-
+
BUS
Input EMI filter
LCL filter
Output relay
Output EMI filter
AC SPD
N
PE
PV1+
PV1-
DC SPD
DC switch
MPPT2
PV2+
PV2-
Residual current
detection
Figure2-6 Working principle diagram
When the DC input (PV) has 2 groups of PV strings, the larger power one should be prior to connect
with PV1, the other should be connected with PV2.

PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
3 Installation
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3 Installation
This chapter mainly introduces the inverter's installation, including installation process, installation
preparation, transportation and unpacking, installation procedures, electrical connection. check the
installation, etc.
3.1 Installation Process
Start
Electrical
connection
Check the
installation
End
Installation
preparation
Inverter
installation
Figure3-1 Installation process
3.2 Installation Preparation
3.2.1 Installation Tools
Tools

3 Installation
PV Grid-tied Inverter SPI-B X2 Series (8K-25K)
User Manual
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Tools
The installation tools need to be insulated to avoid electric shock.
3.2.2 Installation Environment
Do not install the inverter in the place with poor ventilation.
Ensure that there has sufficient fresh-air supply around the inverter.
The inverter must be installed on the wall or bracket with enough bearing capacity.