Sungrow SG250K3 User manual

SG250K3
Grid-Connected Inverter
Operation Manual
SG250K3-3A-E-Ver21-200903
Version: 2.1

Release History
Version
Release Date
2.1
Mar,2009
Author
Approved By
Chen Wei
Zhao Wei

About This Manual
Aim
The aim of this Operation Manual is to give detail explanations and
instructions for operation, maintenance and troubleshooting of the
SG250K3 Grid Connected Inverter.
Target Readers
The Manual is provided to people who need to operate the SG250K3 grid
connected inverter.

Symbols Explanation
The following symbols are used in this manual .
Warning: risk of electric shock.
Caution: risk of danger
Note: Note indicates a feature that is important either for optimal
and efficient system operation
PROTECTIVE CONDUCTOR TERMINAL
Caution: risk of electric shock, Energy storage timed discharge.

Table of Contents
1. Safety Instructions.............................................................................................................1
1.1. Service Safety..........................................................................................................3
1.2. Open the Door of SG250K3........................................................................................3
2. Introduction .....................................................................................................................5
2.1. PV Generation System..............................................................................................5
2.2. Basic Structure ............................................................................................................6
2.3. Status and Control Elements.....................................................................................7
2.3.1. The LED Indicators..........................................................................................7
2.3.2. Functions of the Touch Screen ..........................................................................8
2.3.3. Emer ge ncy Stop Button ........................................................................................8
2.3.4. Start/Stop Switch ................................................................................................8
2.3.5. D C Breaker......................................................................................................8
2.3.6. AC Breaker ......................................................................................................8
3. Commissioning .................................................................................................................10
3.1. Visual Inspection ...................................................................................................10
3.1.1. AC Connection Check ........................................................................................10
3.1.2. DC Connection Check .......................................................................................10
3.1.3. Ground Connection Check ..................................................................................10
3.1.4. Serial Communication Check (Optional) ..................................................................10
3.2. Start the Inverter ........................................................................................................11
3.3. How to Restart after Using the Emergency Stop Button ..............................................11
4. Operation .......................................................................................................................13
4.1. Operation Modes .....................................................................................................13
4.2. Modes Transition ......................................................................................................14
5. Data Interface ..................................................................................................................16
5.1. LED Indicators.......................................................................................................16
5.2. Touch Screen Control Panel ..........................................................................................17
5.2.1. The Background Illumination .........................................................................17
6. Touch screen Control Menu.............................................................................................19
6.1. Default Menu (Main Window) .................................................................................20
6.2. Start the Inverter....................................................................................................21
6.3. Stop the Inverter ....................................................................................................23
6.4. Check Running Data..............................................................................................25
6.5. Check History Data ...............................................................................................28
6.6. Entering the Password ............................................................................................31
6.7. Change Display Language.....................................................................................33
6.8. Change System Time .............................................................................................35
6.9. Parameters Adjustment ..........................................................................................37
6.9.1. Generated Energy Adjustment .......................................................................37
6.9.2. Load Default Setup .......................................................................................39
6.9.3. Set Running Parameters.................................................................................41
6.9.4. Protection Parameter Limit .............................................................................43
6.9.5. Communication Parameter Setup...................................................................45
7. Maintenance ...................................................................................................................48

8. Troubleshooting .............................................................................................................50
8.1. LED Indicated Fault Troubleshooting........................................................................50
8.2. Touch Screen Displayed Fault Troubleshooting ......................................................... 51
9. Appendix A: Technical Data ...................................................................................................54
9.1. Input Parameters ...................................................................................................54
9.2. Output Parameters ................................................................................................54
9.3. Efficiency ..............................................................................................................54
9.4. Mechanical Parameters ..........................................................................................54
9.5. Environmental Parameters......................................................................................55
9.6. Features ...............................................................................................................55
10. Appendix B ..............................................................................................................56
10.1. Exclusion of Liability............................................................................................56
10.2. About us ...............................................................................................................57

List of Figures
Figure 2-1 PV generation system with SG250K3 .................................................................5
Figure 2-2 Simple circuit diagram of SG250K3 ..................................................................6
Figure 2-3 External appearance of SG250K3 .....................................................................7
Figure 4-1 Transition of operation states ..........................................................................14
Figure 5-1 SG250K3 data interface .................................................................................16
Figure 5-2 Touch screen panel ........................................................................................17

List of Tables
Table 2-1 Data and control components ............................................................................7
Table 2-2 Large LED definitions .........................................................................................7
Table 4-1 State explanations of SG250K3 ........................................................................14
Table 5-1 Meaning of LED indicators ...............................................................................16
Table 6-3 Explanations of faults.......................................................................................30
Table 7-1 Maintenance period ........................................................................................48
Table 8-1 LED states during normal working ....................................................................50
Table 8-2 LED fault and simple troubleshooting ................................................................50
Table 8-3 Displayed Fault description and troubleshooting ................................................51

Safety Instructions
Chapter 1 provides some important safety instructions about
SG250K3.

1
1. Safety Instructions
Warning: Shock Hazard
The enclosure of SG250K3 inverter may contain high voltage conductors.
The enclosure doors should be kept locked during operation, except for
maintenance or testing.
To avoid the risk of electric shock, do not perform any action or
operation which is not included in the operating instructions unless you
are qualified to do so
Warning: Shock Hazard
Death resulting from burning and electric shock upon
touching the SG250K3 live components.
•Do not touch the live components of the SG250K3.
•Observe all safety regulations.
Warning: Shock Hazard
The SG250K3 Inverter will immediately shutdown if users want to open the
front door during operation.
Please check the unit is thoroughly shut down and isolated from the public
grid and PV arrays before open the front door,
To avoid the risk of electric shock, a minimum 10 minutes is needed for
any stored potentials that still left in the inverter after shut-down to be
discharged before opening the door
Warning: Lethal V o ltag e
Damage to the SG250K3 may result death by electric shock or fire!
•Only operate SG250K3 when it is safe to do so!
•Only operate SG250K3 when no damage is visibly apparent!
Warning: DC Voltage
The PV array will provide DC voltage to the inverter when exposed to
light, which may cause an electrical shock during installation, wiring or
maintenance if not covered.
Warning: Limitation of Use
The SG250K3 Grid-Connect Photovoltaic Inverter is not intended for use
in connection with life support systems or other medical equipment or
devices.

2
Caution: ESD Precautions
The SG250K3 may be damaged irreversibly by electrostatic discharge
(ESD) at its components.
•During the operation of SG250K3, please observe all the ESD related
safety regulations!
•Discharge any ESD by touching the grounded SG250K3 conductor
before contacting any electronic components!
Caution: Tools Precautions
Thoroughly inspect the equipment prior to energizing. Verify that no
tools or equipment have inadvertently been left behind.
Caution: Service Safety
Never work alone when servicing this equipment. Two persons are
required until the equipment is properly de-energized, locked out and
verified de-energized with a meter.
Note: Keep T his Manual
Please keep this operation manual and other related document in the
handy place of the SG250K3.
These documents must be available to operators and maintenance
personnel at all times.

3
1.1. Service Safety
Never work alone when servicing this equipment. Two persons are
required until the inverter is properly shut down, and verified de-
energized with a meter.
1.2. Open the Door of SG250K3
Use the following procedure to shut down the SG250K3 Inverter before servicing:
1. Stop the inverter from the touch screen control menu.
2. Switch off the DC breaker (turn the switch to the “off” position) and press in
the 2 handles (near the DC breaker) to make it pop out from the lock hole at both
side doors, turn it right. Open the left door.
3. Switch off the AC breaker (turn the switch to the “off” position) and press in
the handle (near the AC breaker) to make it pop out from the lock hole and open
the right door.
Warning: Shock Hazard
The terminals of the SG250K3 PV input may have energy when the PV
arrays a re energized.
After shut down, wait a minimum 5 minutes should be left for all
capacitors of SG250K3 to discharge and left with no potential
10 minutes

4
Introduction
Chapter 2 provides basic information about SG250K3.

5
2. Introduction
Chapter 2 provides basic information about SG250K3.
2.1. PV Generation System
Figure 2-1 PV generation system with SG250K3
As depicted in Figure 2-1, SG250K3 converts the DC power from the PV array to
AC power and then feeds the power into the utility grid (3-phase-400V).

6
2.2. Basic Structure
SG250K3 is an advanced and reliable three-phase grid connected inverter for
solar power generation with a rating of 250kW.The SG250K3 inverter utilizes the
advanced power conversion technology with the latest IPM (Intelligent Power
Module), to convert the DC power from the photovoltaic array to stable three-
phase AC power and then feed the power to the utility grid through Figure
2-2 .
PV Array
+L1
L2
L3
DC EMI
FILTER AC EMI
FILTER
3-phase full bridge(IGBT)
LCL Filter Transformer AC Main Contactor
AC Auxiliaries Contactor
AC Main Breaker
PE
Figure 2-2 Simple circuit diagram of SG250K3

7
2.3. Status and Control Elements
Figure 2-3 shows the locations of basic control and information display elements
that help users perform control and monitoring tasks.
Figure 2-3 External appearance of SG250K3
Table 2-1 Data and control components
Component Name
Comments
LED Indicators
Power, Operation and Fault
touch screen control panel
Display data and perform control functions
DC breaker
DC side circuit breaker switch
AC breaker
AC side circuit breaker switch
Emergency stop button
Shut down the inverter when pressed down
Doorlock
Close or open the case of SG250K3
Start/Stop Switch
The inverter will only start when this switch is in the start position
2.3.1. The LED Indicators
There are 3 large LED indicators in the SG250K3 enclosure, as can be seen in
Figure 2-3; there detail explanations are listed in Table 2-2:
Table 2-2 Large LED definitions
Indicator
Color
Definitions
Power
Green
The power supply of control circuits is OK
Operation
Green
The inverter is running in grid-connected mode
Fault
Red
A fault is occurred and not solved

8
2.3.2. Functions of the Touch Screen
The touch screen panel includes three main parts: the LED indicators, the touch
screen display and the keys.
With this data interface component, users can easily access the running
information of the unit and perform some control functions:
•Control inverter operation
•Display real-time running data
•Display fault data
•Adjusting SG250K3 parameters
•Access recorded history data
2.3.3. Emer ge ncy Stop Button
The Emergency stop button will shutdown the inverter (switch off the AC
contactors and stop the IPM from working) immediately when it is punched
(pressed down). The inverter must be startup manually through touch
screen and keys after the button is punched.
2.3.4. Start/Stop Switch
The inverter can only be started when the start/stop switch is pointed to the
“ start ”position.
When you turn the switch to the “ stop ”position, it will give the inverter a stop
command like the same command of the emergency stop button.
The inverter can not start when the switch is pointed to the “ stop ”position.
2.3.5. D C Breaker
The DC breaker controls the DC main circuit breaker , which is th e primary
disconnect device for the inverter.
When the DC breaker is in the OFF position, all DC power is disconnected (not
live), except the following areas:
• The input side of the AC circuit breaker (connect the utility grid)
• The DC input terminals (if the PV array is connected and energized)
To operate the inverter the DC circuit breaker switch must be in the ON position.
2.3.6. AC Breaker
The AC breaker controls the AC circuit breaker, which is also one of the
primary disconnects for the inverter. When the AC breaker is in the OFF
position, all AC power is disconnected (not live), except the following areas:
• The AC input terminals (connect the utility grid)
• The DC input side (if the PV array is connected and energized)
To operate the inverter the AC circuit breaker switch must be in the ON position.

9
Commissioning
Chapter 3 describes the verification and commissioning of
SG250K3.

10
3. Commissioning
Chapter 3 describes the procedures needed to verify whether your installation of the
SG250K3 is correct and how to start the inverter for the first time.
3.1. Visual Inspection
To perform a visual inspection of theSG250K3:
1. Verify the grid circuit breaker is open.
2. Verify the DC circuit breaker is open.
3. Inspect the polarity of PV input connections are correct.
4. Check all the mechanical connections and make sure there is no damage,
scratch or abnormal parts
5. Check all the electrical connections and secure the wiring terminals.
Make sure the DC and AC side circuit breakers are switched-off.
6. Check all the wiring of AC and DC sides are connected to the correct
thermals with correct rating wires.
7. Make sure all the bolts that fix the wires are tightened and secured.
3.1.1. AC Connection Check
It must be verified that the inverter is connected to the correct grid type and that
a right-hand rotary field exists on L 1 , L 2 , and L3. The value of the AC line to line
voltage should be about 400 V.
3.1.2. DC Connection Check
The DC connections are from the DC combiner boxes to the inverter.
The voltage on the individual DC wires should be almost the same value and
must never exceed the allowable maximum DC voltage.
Besides the voltage values, the polarity of the DC inputs must also be verified. all
DC connections should be checked to ensure that they are
mechanically tight.
3.1.3. Ground Connection Check
Make sure the ground wire goes through the hole of the ground fault detection
device and connected to the ground copper bar securely.
3.1.4. Serial Communication Check (Optional)
For external communication monitoring, the data wires must be connected.
Make sure that the RS485 A and B wires are connected correctly and tightened to
the RS485/232 converter.
Make sure the RS485/232 converter DB9 terminal is correctly connected to the
PC DB9 serial port.

11
3.2. Start the Inverter
Caution:
Before starting the device for the first time , all work performed
on the device should be thoroughly checked.
Caution: Check the voltages in both AC and DC sides meet the
requirements of SG250K3.
If all tests and measurements have been performed, and all measured values lie
within the acceptable range, then the device can be switched on for the first time.
To start the SG250K3:
1. Verify 400 VAC voltage of the transformer primary side line to line voltage.
2. Close the door of the enclosure.
3. Turn the “Start/Stop Switch” to the “start” position.
3. Turn the AC breaker to the “ON” position.
4. Turn the DC breaker to the “ON” position.
5. It will take about 10 seconds for the auto-initialization of the power
conversion circuit and the touch screen panel. The “ POWER ”LED indicator will
burn; the “com” LED indicator will flash every 2 or 3 seconds.
6. If the DC voltage is below the DC voltage start point (Vpv<450V), then the
“state” of the touch screen interface will always show “ Start-up ”;
7. the DC voltage exceeds the DC voltage start point (Vpv >450V) for 1 minute,
the SG250K3 will automatically change to “ Run ” state, the “ OPERATION ” LED
will light, with the state of the touch screen menu will change to “ Run ”.
3.3. How to Restart after Using the Emergency Stop Button
Users must manually restart the inverter according to the following procedure
when the operation of the SG250K3 is stopped by punching the emergency stop
button:
1. Turn the emergency stop button clockwise to release the inverter from the stop
state.
2. Turn the “ Start/Stop Switch ” to the “ Start ” position
3. Perform the stop command in the touch screen menu. (Check section 6.7)
4. Perform the start command in the touch screen menu. (Check section 6.6)
5. Then the inverter will restart.