REFU 801 Series User manual

Version 4 (No. 982065) 801 Series June 2019
Operating Instructions
REFUone 3K-2T ... 7K-2T

REFUone 3K-2T, 5K-2T, 7K-2T
2
Notice
This manual contains important safety instructions that must be followed during installation
and maintenance of the equipment.
Save these instructions!
This manual must be considered as an integral part of the equipment, and must be available
at all times to everyone who interacts with the equipment. The manual must always
accompany the equipment, even when it is transferred to another user or field.
Copyright Declaration
The copyright of this manual belongs to REFU Elektronik GmbH. Any corporation or individual
should not plagiarize, partially copy or fully copy it (including software, etc.), and no
reproduction or distribution of it in any form or by any means. All rights reserved.
REFU reserves the right of final interpretation. This manual is subject to change according to
user’s or customer’s feedback. Please check our website at http://www.refu.com for latest
version.
REFU Elektronik GmbH
Marktstraße 185
D-72793 Pfullingen
Tel.: [phone]
Fax: [phone]
Mail: [email protected]

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Preface
Outline
Please read the product manual carefully before installation, operation or maintenance.This
manual contains important safety instructions and installation instructions that must be
followed during installation and maintenance of the equipment.
Scope
This product manual describes the installation, electrical connections, commissioning,
maintenance and troubleshooting of REFUone 3K-2T …7K-2T inverters.
Keep this manual where it will be accessible at all times.
Target Group
This manual is intended for qualified electrical technical personnel who are responsible for
inverter installation and commissioning in the PV power system and the PV plant operator.
Symbols Used
This manual provides safety operation information and uses the symbol in order to ensure
personal and property security and use the inverter efficiently when operating the inverter.
You must understand these emphasized information to avoid the personal injury and property
loss. Please read the following symbols used in this manual carefully.
Danger indicates a hazardous situation which, if not avoided, will result in death or
serious injury.
Danger
Warning indicates a hazardous situation which, if not avoided, could result in death or
serious injury.
Warning
Caution indicates a hazardous situation which, if not avoided, could result in minor or
moderate injury.
Caution
Attention indicated potential risks which, if not avoided, may lead to equipment fault
or property damage.
Attention
Note provides tips that are valuable for the optimal operation of the product.
Note

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Table of Contents
1Basic safety information ................................................................................... 5
1.1 Safety instructions............................................................................................................................5
1.2 Symbols and signs ............................................................................................................................8
2Product characteristics...................................................................................... 9
2.1 Product dimensions .........................................................................................................................9
2.2 Function description ......................................................................................................................12
2.3 Efficiency curve ..............................................................................................................................13
3Installation ..................................................................................................... 15
3.1 Installation Process ........................................................................................................................15
3.2 Checking Before Installation ..........................................................................................................15
3.3 Tools ...............................................................................................................................................17
3.4 Determining the Installation Position............................................................................................18
3.5 Moving the REFUone inverter ........................................................................................................20
3.6 Installing REFUone inverter............................................................................................................20
4Electrical Connections..................................................................................... 22
4.1 Electrical connection......................................................................................................................22
4.2 Connecting PGND Cables ...............................................................................................................22
4.3 Connecting DC Input Power Cables ...............................................................................................24
4.4 Connecting AC Output Power Cables.............................................................................................26
4.5 Connecting Communications Cables..............................................................................................30
4.6 WiFi/GPRS module installation procedure ............................................................................34
4.7 WiFi Communication......................................................................................................................35
4.8 Monitoring Portal REFUlog ............................................................................................................36
4.9 RS485 Communication...................................................................................................................37
5Commissioning of inverter .............................................................................. 38
5.1 Safety inspection before commissioning.......................................................................................38
5.2 Start Inverter ..................................................................................................................................38
6Operation interface ........................................................................................ 39
6.1 Operation and Display Panel..........................................................................................................39
6.2 Standard Interface..........................................................................................................................40
6.3 Main Interface................................................................................................................................41
6.4 Update Software online .................................................................................................................47
7Trouble shooting and maintenance ................................................................. 50
7.1 Trouble shooting.............................................................................................................................50
7.2 Maintenance ..................................................................................................................................55
8Technical data ................................................................................................. 56
8.1 DC Data...........................................................................................................................................56
8.2 AC Data...........................................................................................................................................56
8.3 Efficiency, Protection and Communication ...................................................................................56
8.4 General Data ..................................................................................................................................57
9Quality Assurance ........................................................................................... 58
10 Technical Support ........................................................................................... 59

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1 Basic safety information
If you have any question or problem when you read the following information,
please contact REFU Elektronik GmbH.
Note
Outlines of this chapter
Safety instruction
It mainly introduce the safety instruction when install and operate the equipment.
Symbols and signs
It mainly introduce the safety symbols on the inverter.
1.1 Safety instructions
Read and understand the instructions of this manual, and be familiar with relevant safety
symbols in this chapter, then start to install and troubleshoot the equipment.
According to the national and state requirements, before connecting to the electrical grid, you
must get permission from the local electrical grid operator, and the operation can only be
performed by qualified electrical engineer.
Please contact the nearest authorized service center if any maintenance or repair is needed.
Contact your distributor for the information of the nearest authorized service center. Do NOT
repair it by yourself, it may cause injury or property damage.
Before installing and maintaining the equipment, you should turn the DC switch OFF to cut off
the high voltage DC of the PV array. You can also turn the switch in the PV combiner box OFF to
cut off the high voltage DC. Otherwise, serious injury may be caused.
1.1.1 Qualified persons
The customer must make sure the operator has the necessary skill and training to do his/her
job. Staff in charge of using and maintaining the equipment must be skilled, aware and mature
for the described tasks and must have the reliability to correctly interpret what is described in
the manual. For safety reason only a qualified electrician, who has received training and / or
has demonstrated skills and knowledge in construction and in operation of this unit, can install
this inverter. REFU Elektronik GmbH does not take any responsibility for the property
destruction and personal injury because of any incorrect use.
1.1.2 Installation requirements
Please install inverter according to the following section. Fix the inverter on an appropriate
objects with enough load bearing capacity (such as walls, PV racks etc.), and ensure that
inverter is vertical placed. Choose a place suitable for installing electrical devices. Assure there
is enough fire exit space, convenient for maintenance. Maintain proper ventilation to ensure
enough air cycle to cool the inverter.

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REFUone 3K-2T / 5K-2T REFUone 7K-2T
1.1.3 Transport requirements
If you find packing problems that may cause the damage of the inverter, or find any visible
damage, please immediately notice the responsible transportation company. You can ask solar
equipment installation contractor or REFU Elektronik GmbH for help if necessary. Transport of
the equipment, especially by road, must be carried out by suitable ways and means for
protecting the components (in particular, the electronic components) from violent shocks,
humidity, vibration, etc.
1.1.4 Electric connection
Please comply with all the current electrical regulations about accident prevention in dealing
with the solar inverter.
Before the electrical connection, make sure to use opaque material to cover
the PV modules or to disconnect PV array DC switch. Exposure to the sun,
PV array will produce a dangerous voltage!
Danger
All installation accomplished only by professional electrical engineer!
must be trained;
Completely read the manual operation and understand relevant
matters.
Warning
Get permission from the local electrical gird operator, complete all electrical
connections by professional electrical engineer, then connect inverter to
electrical grid.
Attention
It’s forbidden to remove the tamper evident label, or open the inverter.
Otherwise REFU will not provide warranty or maintenance!
Note

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1.1.5 Operation
Touching the electrical grid or the terminal of the equipment may lead to
electrocution or fire!
Don’t touch the terminal or conductor connected to the electrical grid.
Pay attention to any instructions or safety documents related to grid
connection.
Danger
Some internal components will be very hot when inverter is working.
Please wear protective gloves!
Attention
1.1.6 Maintenance and repair
Before any repair work, turn OFF the AC circuit breaker between the
inverter and electrical grid first, then turn OFF the DC switch.
After turning OFF the AC circuit breaker and DC switch, wait for 5
minutes at least before carrying out any maintenance or repair work.
Danger
Inverter should work again after removing any faults. If you need any
repair work, please contact with the local authorized service center;
Can’t open the internal components of inverter without authorized.
REFU Elektronik GmbH does not take any responsibility for the losses
from that.
Attention
1.1.7 EMC / noise level of inverter
Electromagnetic compatibility (EMC) refers to that one electrical equipment functions in a
given electromagnetic environment without any trouble or error, and impose no unacceptable
effect upon the environment. Therefore, EMC represents the quality characters of an electrical
equipment.
The inherent noise-immune character: immunity to internal electrical noise.
External noise immunity: immunity to electromagnetic noise of external system
Noise emission level: influence of electromagnetic emission upon environment.
Electromagnetic radiation from inverter may be harmful to health!
Please do not continue to stay around the inverter in less than 20 cm when
inverter is working.
Danger

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1.2 Symbols and signs
1.2.1 Safety symbols
Caution of burn injuries due to hot enclosure!
You can only touch the screen and pressing key of the inverter while it’s
working.
Caution
PV array should be grounded in accordance to the requirements of the local
electrical grid operator!
We suggest that all PV module frames and inverter are reliably grounded to
protect the PV system and personnel security.
Attention
Ensure input DC voltage < Max. DC voltage .Over voltage may cause
permanent damage to inverter or other losses, which will not be included in
warranty!
Warning
1.2.2 Signs on the inverter
There are some symbols, which are related to security on the inverter. Please read and
understand the content of the symbols, and then start the installation.
There is a residual voltage in the inverter! Before opening the
equipment, operator should wait for five minutes to ensure the
capacitor is discharged completely.
Caution, risk of electric shock.
Caution, hot surface.
Comply with the Conformite Europeenne (CE) certification.
Grounding point.
Please read this manual before install REFUone inverters.
IP65
This indicates the degree of protection of the equipment according to
IEC standard 70-1 (EN 60529 June 1997).
Positive pole and negative pole of the input voltage (DC).

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2 Product characteristics
Outlines of this chapter
Product dimensions
It introduces the field of use, and the overall dimensions of the REFUone inverters.
Function description
It introduces how REFUone inverters work and the function modules inside.
Efficiency curves
It introduces the efficiency curves of in the inverter.
2.1 Product dimensions
2.1.1 Field of use
REFUone inverters are Dual MPPT grid-tied PV inverters which converts the DC power
generated by PV arrays into sine wave single-phase AC power and feeds it to the public
electrical grid, AC circuit breaker (refer to Section 4.4) and DC switch used as disconnect
device, and the disconnect device shall be easily accessible.
PV Grid-tied System
REFUone inverters can only be used with photovoltaic modules that do not require one of the
poles to be grounded. The operating current during normal operation must not exceed the
limits specified in the technical specifications. Only the photovoltaicmodules can be connected
to the input of the inverter (do not connect batteries or other sources of power supply).
The choice of optional parts of inverter should be made by a qualified technician who knows
the installation conditions clearly.
Overall dimensions REFUone 3K-2T and 5K-2T (L×W×H): 437 mm×324 mm×130 mm.
Overall dimensions REFUone 7K-2T (L×W×H): 467 mm×352 mm×157 mm.

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352.0 mm
467.0 mm
157.0 mm
Front view and left view dimensions of REFUone 3K-2T and 5K-2T
Front view and left view dimensions of REFUone 7K-2T
324.0 mm
437.0 mm
130.0 mm
4 6 7 . 0 m m

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Back view and Bracket dimensions REFUone 3K-2T and 5K-2T
Back view and Bracket dimensions REFUone 7K-2T
291.0 mm
110.0 mm 110.0 mm
130.5 mm
170.3 mm
160.0 mm
28.5 mm
9.0 mm
314.0 mm
258.7 mm
87.5 mm 87.5 mm
90.0 mm
265.0 mm
177.0 mm
6.5 mm 85.0 mm
85.0 mm
86.0 mm
87.5 mm

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2.1.2 Labels on the equipment
The labels must NOT be hidden with
objects and extraneous parts (rags,
boxes, equipment, etc.); they must
be cleaned regularly and kept
visible at all times.
2.2 Function description
DC power generated by PV array is filtered through Input Board before entering into Power
Board. Input Board also offer functions such as insulation impedance detection and input DC
voltage / current detection. DC power is converted to AC power by Power Board. AC power is
filtered through Output Board then AC power is fed into the grid. Output Board also offer
functions such as grid voltage / output current detection, GFCI and output isolation relay.
Control Board provides the auxiliary power, controls the operation state of inverter and shows
the operation status by Display Board. Display Board displays fault code when inverter is in
abnormal operation conditions. At the same time, Control Board can trigger the relay so as to
protect the internal components.
Function module
1. Energy management unit
This control can be used to switch the inverter on/off through an external (remote) control.
2. Feeding reactive power into the grid
The inverter is able to produce reactive power and can therefore feed it into the grid through
the setting of the phase shift factor. Feed-in management can be controlled directly by the
grid company through a dedicated RS485 serial interface.
3. Limiting the active power fed into the grid
The inverter, if enabled can limit the amount of active power fed into the grid by the inverter
to the desired value (Expressed as a percentage).
4. Self power reduction when grid is over frequency
When the grid frequency is higher than the limited value, inverter will reduce output power
which is necessary for the grid stability.
5. Data transmission
The inverter or a group of inverters may be monitored remotely through an advanced
communication system based on RS-485 serial interface, or remotely via the WiFi.
6. Software update
SD card is used for updating the firmware.
Máx. tensão Entrada CC (Vmax)
Faixa de voltagem do MPPT
Máx. corrente entrada CC (Iop)
Máx. corrente de curto entrada CC (Icc)
Tensão CA nominal da rede
Corrente CA nominal de saída
Potência nominal de saída
Frequência nominal da rede
Fator de potência
Grau de proteção
Faixa de temperatura de operação
Classe de proteção
2x11 A
2x13.2 A
22.8 A
50 Hz
5000 W
90~580 V
220 V
IP65
Inversor Solar
Grid-Tied
Topologia do inversor Não isolado
600 V
1 (ajustável +/-0.8)
-25°C a +65°C
Classe 1
Modelo: REFUone 5K-2T
fabricados na República Popular da China
REFU Elektronik GmbH, Marktstrasse 185
72793 Pfullingen, Alemanha www.refu.com
Tipo: 801P005.200

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Electrical block diagram
Electrical block diagram
2.3 Efficiency curve
Efficiency Curve REFUone 3K-2T
82%
84%
86%
88%
90%
92%
94%
96%
98%
100%
5% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Efficiency [%]
% of Rated Output Power
Vpv=250V
Vpv=365V
Vpv=450V

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Efficiency Curve REFUone 5K-2T
Efficiency Curve REFUone 7K-2T
82%
84%
86%
88%
90%
92%
94%
96%
98%
100%
5% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Efficiency [%]
% of Rated Output Power
Vpv=300V
Vpv=365V
Vpv=450V

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Moving the
Inverter
3 Installation
Outlines of this chapter
This topic describes how to install the REFUone inverters.
Installation notes
Do NOT install the REFUone inverter on flammable material.
Do NOT install the REFUone inverter in an area used to store flammable or
explosive materials.
Danger
The enclosure and heat sink are very hot while the inverter is working, therefore
do NOT install the REFUone inverter in places where you might touch them
inadvertently.
Caution
Consider the weight of the inverter when transporting and moving.
Choose an appropriate mounting position and surface.
Assign at least two persons to install the inverter.
Attention
3.1 Installation Process
Installation flowchart
3.2 Checking Before Installation
3.2.1 Checking Outer Packing Materials
Packing materials and components may be damaged during transportation. Therefore, check
the outer packing materials before installing the inverter. Check the outer packing materials
for damage, such as holes and cracks. If any damage is found, do not unpack the REFUone
inverter and contact the dealer as soon as possible. You are advised to remove the packing
materials within 24 hours before installing the REFUone inverter.
3.2.2 Checking Deliverables
After unpacking the inverter, check whether deliverables are intact and complete. If any
damage is found or any component is missing, contact the dealer.
End
Install the
Inverter
Install the rear panel
Check before
installation
Prepare installation
tools
Determine the
installation position

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Table 1 shows the components and mechanical parts that should be delivered
No.
Pictures
Description
Quantity
REFUone 3K-
2T, 5K-2T
Quantity
REFUone 7K-2T
1
REFUone inverter
1 pcs
1 pcs
2
Rear panel
1 pcs
1 pcs
3
PV+ input terminal
2 pcs
3 pcs
4
PV-input terminal
2 pcs
3 pcs
5
Metal terminals secured
to PV+ input power cables
2 pcs
3 pcs
6
Metal terminals secured
to PV- input power cables
2 pcs
3 pcs
7
M5 Hexagon screws
3 pcs
3 pcs
8
M6 flat washer
7 pcs
10 pcs
9
Expansion bolts
7 pcs
10 pcs
10
Self-tapping screw
5 pcs
8 pcs
11
Manual
(English and Portugese)
1 pcs
1 pcs
12
AC output terminal
1 pcs
-

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13
485 terminal (2pin)
1 pcs
-
14
AC connection housing
-
1 pcs
3.3 Tools
Prepare tools required for installation and electrical connections.
Table 2 shows the tools required for installation and electrical connections.
No.
Tool
Model
Function
1
Hammer drill
Recommend drill dia.
6mm
Used to drill holes on the wall
2
Screwdriver
wiring
3
Removal tool
Remove PV terminal
4
Wire stripper
Strip wire
5
4mm Allen Wrench
Turn the screw to connect rear panel
with inverter
6
Crimping tools
Used to crimp power cables
7
Multi-meter
Used to check grounding
8
Marker
Used to mark signs
A1
4.0

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9
Measuring tape
Used to measure distances
10
Level
Used to ensure that the rear panel is
properly installed
11
ESD gloves
Operators wear
12
Safety goggles
Operators wear
13
Anti-dust respirator
Operators wear
3.4 Determining the Installation Position
Determine an appropriate position for installing the REFUone inverter. Comply with the
following requirements when determining the installation position:
Installation Requirements
0-180º

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clearance for single REFUone inverter
Installation of multiple REFUone inverters

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3.5 Moving the REFUone inverter
This topic describes how to move the REFUone horizontally to the installation position
Step 1 Open the packaging, insert hands into the slots on both sides of the inverter and hold
the handles, as shown in Figure 14and Figure 15.
Moving the inverter (1)
Moving the REFUone inverter (2)
Step 2 Lift the REFUone from the packing case and move it to the installation position.
To prevent device damage and personal injury, keep balance when moving the
inverter because the inverter is heavy.
Do not put the inverter with its wiring terminals contacting the floor because
the power ports and signal ports are not designed to support the weight of the
inverter. Place the inverter horizontally.
When placing the inverter on the floor, put foam or paper under the inverter to
protect its shell
Attention
3.6 Installing REFUone inverter
Step 1 Determine the positions for drilling holes, ensure the hole positions are level, then mark
the hole positions using a marker pen, use the hammer drill to drill holes on the wall. Keep the
hammer drill perpendicular to the wall, do not shake when drilling, so as not to damage the
wall. If the error of the hole positions is too big, you need to reposition.
Step 2 Insert the expansion bolt vertically into the hole, pay attention to the insertion depth
of the expanding bolt (should be deep enough).
Step 3 Align the rear panel with hole positions, fix the rear panel on the wall by tightening the
expansion bolt with the nuts.