Riello RS Series User manual

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INTRODUCTION
Thank you so much for choosing RS 1.5-6.0, the latest generation of grid-tied PV string inverters (hereinafter referred to as the
“inverter”) designed and developed by Riello Solartech.
Our company is specialised in the development and production of photovoltaic inverters. The solar inverters in this series are high-
quality products, carefully designed and constructed with the aim of ensuring high performance.
This equipment can be used by any person, provided they READ THIS MANUAL CAREFULLY AND THOROUGHLY.
This user manual introduces the inverter in terms of its installation, electrical connections, operation, commissioning, maintenance
and troubleshooting.
For information regarding use and to obtain maximum performance from your equipment, this manual should be stored
carefully near the inverter and CONSULTED BEFORE OPERATION.
NOTE: some images contained in this document are for information purposes only and may not faithfully reproduce the parts of the
product represented.
Application Model
Grid-tied PV string inverter
•RS 1.5/2.0/3.0 PV inverter with single MPPT input
•RS 4.0/5.0/6.0 PV inverter with double MPPT input
Intended Recipients
This user manual is intended for photovoltaic (PV) inverter operating personnel and qualified electrical technicians.
Note:
this user manual is subject to change (specific please in kind prevail) without prior notice. The latest version of the user manual and
additional information on the product are available on http://www.riello-solartech.com, and/or by consulting your dealer.
Symbol Conventions
The safety symbols used in this manual, which highlight potential safety risks and important safety information, are listed below:
Symbol
Description
DANGER
Indicates an imminently hazardous situation which, if not correctly followed, will result in serious injury or
death.
WARNING
Indicates apotentially hazardous situation which, if not correctly followed, could result in serious injury or
death.
CAUTION
Indicates apotentially hazardous situation which, if not correctly followed, could result in moderate or minor
injury.
NOTICE
Indicates apotentially hazardous situation which, if not correctly followed, could result in equipment failure
or property damage.
NOTE
Calls attention to important information, best practices and tips:
supplements the safety instructions to optimise your use of the PV inverter and reduce wastage of
resources.
Refer
Refer to documentation (Remind operators to refer to the documentation shipped with the inverter).

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SAFETY PRECAUTIONS
Before using the product, please read these safety precautions in the User Manual carefully.
Personnel Safety
•The PV inverter must be installed, electrically connected, operated and maintained by a specially trained technician.
•The qualified technician must be familiar with the safety regulations concerning the electrical system, the working process
of the PV power generation system and the standards of the local power grid.
•The technician must read through this User Manual carefully and master it before any operation.
PV Inverter Protection
NOTICE
Upon receiving the PV inverter, please check whether it was damaged during transport. If it was, please contact
your dealer immediately
•Do not tamper with any warning signs on the inverter’s enclosure, because these signs contain important information on
safe operation.
•Do not remove or damage the nameplate on the inverter’s enclosure, because it contains important product information.
Installation Safety
NOTICE
Please read the User Manual carefully before installing the PV inverter; warranty or liability will be voided if
damage is caused by installation faults.
•Ensure that there are no electrical connections around the PV inverter ports prior to installation.
•Adequate ventilation must be provided in the inverter’s installation location. Mount the inverter in the vertical direction and
ensure that no object is placed on the heat sink, as this may affect the cooling efficiency (for details, refer to Chapter 4 -
Installation).
Electrical Connections
DANGER
Before installing the inverter, check all electrical ports to ensure that there are no
damages or short-circuits. Otherwise, personal injury and/or fire will occur.
•Input terminals of the PV inverter apply only to input terminals of the PV string; do not connect any other DC source to the
input terminals.
•Before connecting PV modules, ensure that their voltage is within the safe range; when exposed to any sunlight, PV modules
can generate high voltage.
•All electrical connections must meet the electrical standards of the relevant country or region.
•Cables used for electrical connections must be properly secured, well-insulated and made to the appropriate specification.
Operation and Commissioning
DANGER
While the inverter operates, high voltage can lead to an electrical shock hazard and even cause personal injury.
Therefore, operate the PV inverter strictly according to the safety precautions in this User Manual.
•Unless permission has been obtained from the power company of the country/region, the grid-tied PV inverter cannot start
generating power.
•Follow the procedures for commissioning described in the User Manual when commissioning the PV inverter.
•When the PV inverter is operating, do not touch the surface of any other parts except for the DC switch; its constituent parts
will be extremely hot and can cause burns.
Maintenance
DANGER
Power OFF all electrical terminals before performing inverter maintenance; strictly comply with the safety
precautions stated in this document when operating the inverter.
•For personal safety, maintenance personnel must wear appropriate personal protective equipment (such as insulation gloves
and protective shoes) for inverter maintenance operations.
•Place temporary warning signs or erect fences to prevent unauthorised access to the maintenance site.
•Strictly follow the maintenance procedures specified in the User Manual.
•Check the relevant safety and performance of the inverter; rectify any faults which may compromise the safe operation of
the inverter before restarting the latter.
Additional Information
NOTICE
To avoid any other unforeseeable risk, contact Riello immediately if any safety issue emerges during operation.
.

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PROTECTING THE ENVIRONMENT
Our company has devoted extensive resources to the analysis of environmental aspects in the development of our products. All our
products pursue the objectives set out in the environmental management system policy, developed by our company in accordance
with current legislation.
This product does not contain hazardous materials such as CFCs, HCFCs or asbestos.
Product packaging is made from RECYCLED MATERIALS. The disposal of individual components must be performed in accordance
with current legislation in the country where the product is used. Refer to the following table for material identification:
DESCRIPTION
MATERIAL
Packaging box
Corrugated cardboard (PAP)
Protective bag
High-density polyethylene (HDPE)
Foam
Low-density polyethylene (LDPE)
Bubble wrap
LIMITED GUARANTEE
The equipment you have purchased has been constructed according to the most modern techniques and was rigorously tested before
leaving the factory.
During the guarantee period, the manufacturer shall repair or replace parts that prove defective, provided that such defects have not
been caused by incompetence or negligence of the buyer, fortuitous events or force majeure (lightning, fire, flood, etc.), incorrect or
inadequate installation other than as stated in the manual, unsuitable transport or delivery, opening of the unit by unqualified personnel
or breaking of the closure seal, modification, testing or unauthorised repair, use or application beyond the limits defined by the manual,
or application beyond those defined by safety standards (VDE, UL, etc.).
It is the responsibility of the person applying for technical assistance from Customer Service to provide detailed information about the
detected failure or malfunction.
The repair and/or replacement of parts or the device shall be implemented at the discretion of the supplier.
Any repair under guarantee will be performed by the manufacturer or an authorised service centre. Equipment must arrive at the risk
and expense of the customer in its original packaging so as not to cause further damage.
If repairs must be performed directly at the customer’s premises, the customer shall be charged for expenses and hours of travel,
while the costs for labour and parts shall be borne by the manufacturer. This guarantee does not in any case cover the replacement
of equipment or compensation for any direct or indirect costs or claims for damage caused by device malfunction.
© No part of this manual may be reproduced without prior permission from the manufacturer.
For the purpose of improvement, the manufacturer reserves the right to change the product described at any time and without notice.

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CONTENTS
PRESENTATION _________________________________________________________________________ 5
Product presentation _________________________________________________________________________ 5
INSTALLATION _________________________________________________________________________ 9
Preliminary checks ___________________________________________________________________________ 9
Electrical installation _________________________________________________________________________ 17
USE _________________________________________________________________________________ 23
System Operation ___________________________________________________________________________ 23
User Interface ______________________________________________________________________________ 23
Maintenance _______________________________________________________________________________ 25
Troubleshooting ____________________________________________________________________________ 26
Storage____________________________________________________________________________________ 28
Disposal of the inverter_______________________________________________________________________ 28
CONFIGURATION & MONITORING ________________________________________________________ 29
Introduction________________________________________________________________________________ 29
“RS Connect” app ___________________________________________________________________________ 29
“RS MONITORING” CLOUD PORTAL _____________________________________________________________ 34
APPENDIX ____________________________________________________________________________ 42
Technical Specifications ______________________________________________________________________ 42

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PRESENTATION
PRODUCT PRESENTATION
This chapter introduces the inverter and describes its functional model, network application, appearance, dimensions and working
process, etc.
Functional Model
Function
This series consists of a single-phase grid-tied PV string inverter (transformerless) which converts the DC power generated by PV
strings into AC power and feeds the power into the power grid.
WARNING
The inverter is transformerless. Add an isolation transformer before grounding the positive/negative terminal
of the PV modules (such as a thin-film module) for operation.
WARNING
Do not connect PV modules in parallel to several PV inverters for operation.
Model Description
The number in the model name indicates the power class of the inverter, for example, model RS 3.0 is a 3 kW inverter.
Network Application
Grid-tied PV Power Systems
The series included grid-tied PV power systems for outdoor power stations. Typically, a grid-tied PV power system consists of PV
modules, grid-tied inverters, AC distribution units and a low-voltage power grid, as shown in the figure below.
PV string
Inverter
Low-voltage power grid
RS 3.0
Power class 3 kW

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Outline and Dimensions
RS 1.5-2.0 3.0 PV inverter with single MPPT input (UoM: mm)
RS 4.0/5.0/6.0 PV inverter with double MPPT input (UoM: mm)
Bottom view RS 1.5/2.0/3.0
Bottom view RS 4.0/5.0/6.0

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Connections Area
(1) Vent valve
(2) DC isolation breaker
(3) PV string terminal
(4) AC output connector
(5) Communications interface
(6) External protection ground interface
Indicator Panel View LED and LCD Area
(1) PV indicator
(2) Grid indicator
(3) COM indicator
(4) Warning indicator
(5) LCD

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Working Process
Basic principle description
The RS 1.5/2.0/3.0 PV inverters with single MPPT input receives inputs from only one string of PV panels. The RS 4.0/5.0/6.0 PV
inverters with double MPPT input receive inputs from two strings of PV panels. Then the inputs are grouped into one or two
independent MPPT routes inside the inverter to track the maximum power point of the PV panels. The MPPT power is then converted
into DC bus and the DC power is converted to AC power through an inverter circuit. Lastly, the AC power is fed into the power grid.
An EMI filter is used on both the DC and AC sides to reduce electromagnetic inference; surge protection is supported on the AC side.
Circuit Diagrams
The diagram below shows the circuit blocks of the 1.5 kW-3 kW PV inverters with single MPPT input:
The diagram below shows the circuit blocks of the 4kW-6 kW inverters with double MPPT input:
Operating Modes
The following three operating modes of the inverter are described below: stand-by, operating, and shutdown.
The table below shows the conditions for the inverter to switch between operating modes.
Mode
Description
Stand-by
The PV inverter enters the stand-by mode when:
•The input voltage of the PV string can enable the auxiliary power supply to run but cannot meet the inverter
operation requirements.
•The input voltage of the PV string can meet the inverter start-up requirements but cannot meet its minimum
power requirements.
Operating
When the PV inverter is grid-tied and generates electricity, it tracks the maximum power point to maximise the PV
string output. It converts DC power from PV strings into AC power and feeds the power into the power grid.
The PV inverter will enter the shutdown mode if a fault is detected or a shutdown command is given.
Shutdown
The PV inverter switches from stand-by or operating mode to shutdown mode if a fault is detected or a shutdown
command is given.
The inverter switches from shutdown mode to stand-by mode if a start-up command is given or when it detects that
a fault has been rectified.
DC
EMI
Filter
1
MPPT
Route
Relay
L
N
PE
PV DC
Switch
DC
EMI
Filter
1
MPPT
Route1
PV DC
Switch
Relay
L
N
PE
MPPT
Route2
DC
EMI
Filter
2

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INSTALLATION
PRELIMINARY CHECKS
DANGER
Do not install the inverter on flammable building materials or in an area where flammable or explosive
materials are stored.
CAUTION
Do not install the inverter in a place where personnel are likely to come into contact with its enclosure and
heat sinks, to avoid electrical shock or burns.
Checking the packaging contents
•Upon receiving the inverter, check that the packaging materials are intact.
•After unpacking, check that the deliverables are complete, intact and consistent with your order list.
•Examine the PV inverter and its fittings for any damage such as scraps and cracks.
ITEM
DESCRIPTION
A
PV Inverter
B
Rear panel
C
Manuals
D
AC output connector
E
DC terminal connector group
F
Screws
G
Expansion plugs kit
(for tightening the rear panel)
H
Wi-Fi antenna
I
Removal tool for DC connectors
NOTICE
If any of the damage mentioned above is found, contact the dealer immediately.
HG I

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Moving the inverter
After checking the outer packaging, move the PV inverter to the designated installation position horizontally. Grip the handles on both
sides of the inverter, as shown in the figure below.
CAUTION
Do not place the PV inverter with its wiring terminals in contact with the floor, because the power ports and signal
ports at the bottom of the device are not designed to bear the weight of the inverter.
When placing the inverter on the floor horizontally, place foam or paper under it to protect its enclosure.
Identifying the PV Inverter
Nameplate
After removing the PV inverter from its packaging box, identify it by reading its nameplate affixed to the side of the inverter. The
nameplate contains important product information: model, communication/technical specifications and compliance symbols.
Risk of electric shock
The device contains high voltages, both alternating and direct current, and high leakage currents may be generated
during operation. To avoid the risk of electric shock during maintenance or installation, make sure that all DC and AC
connection terminals are disconnected. First connect the grounding wire to ground and disconnect it last during
maintenance. Check for the proper phase and neutral connection. If the unit is used without following the
specifications of the manufacturer, the protection provided by the equipment may be impaired.
Disconnect the inverter from the grid and from the photovoltaic generator before cleaning the photovoltaic modules:
an unexpected capacitive current from the surface of the modules may surprise operators, causing them to fall off
the roof.
Handling the photovoltaic inverter
The photovoltaic inverter must only be handled by qualified service personnel. When the photovoltaic generator is
exposed to sufficiently intense light, it generates DC voltage, and when connected to the device, it charges the bulk
capacitor. After having disconnected the photovoltaic inverter from the grid and the photovoltaic generator, an electric
charge may remain in the bulk capacitor. Please wait at least 10 minutes after disconnecting the device from the grid
before handling it.
Exclusively for the grid
The PV inverter is designed for the sole purpose of converting energy from PV modules and injecting it into the grid.
This inverter is not designed to be powered by sources of primary energy other than PV modules or to be connected
to different loads other than the public grid.
Hot surfaces
Although it has been designed in accordance with international safety standards, the photovoltaic inverter may
become hot during operation.
Disposal
If the inverter service life has expired, dispose of the device in accordance with local rules for disposal of electrical
equipment waste. Do not dispose of PV inverter with household waste.
10 m i ns

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Installation Requirements
These apply to wall-mounted installation, as described below in detail.
Determining the Installation Position
Basic Requirements
•The inverter is protected to IP65 and can be installed indoors or outdoors.
•The installation method and position must be appropriate for the weight and dimensions of the inverter.
•Do not install the inverter in a place where personnel are likely to come into contact with its enclosure and heat sinks,
because these parts are extremely hot during operation.
•Do not install the inverter in an area where flammable or explosive materials are stored.
Installation Environment Requirements
•The ambient temperature must be below 50℃, which ensures the inverter’s optimal operation and extends its service life.
•The inverter must be installed in a well-ventilated environment to ensure good heat dissipation.
•The inverter must not be directly exposed to sunlight, rain and snow to avoid shortening its service life. It is recommended
that the inverter be installed in a sheltered place. If no shelter is available, build an awning, as shown in the figure below.
Carrier Requirements
•The carrier where the inverter is installed must be fireproof. Do not install the inverter on flammable building materials.
•The wall must be solid enough to bear the weight of the inverter.
•Do not install the inverter on a wall made of gypsum boards or similar materials.

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Installation Space Requirements
•It is recommended that the inverter be installed at eye level to facilitate operation and maintenance.
•Reserve enough clearance around the inverter to ensure sufficient space for installation and heat dissipation, as shown in
the figure below.
Front view
Side view
When installing multiple inverters, install them along the same line if sufficient space is available, or in a triangle pattern or stacked if
there is insufficient space. The installation modes ensure sufficient space for installation and heat dissipation (see following figures
for more details).
Installation along the same line (UoM: mm)

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NOTICE
The clearance between multiple inverters must be increased to ensure proper heat dissipation when they are
installed in a hot area.
Installation in triangle pattern (UoM: mm)
Installation in stacked mode (UoM: mm)
200
1000

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Installation Mode Requirements
Install the inverter upright or with a maximum backward tilt angle of 15 degrees to facilitate heat dissipation.
Below are some correct/wrong installation modes.
Upright
Backward tilt
Upside-down
Horizontal
NOTICE
Incorrect installation will lead to failure of the inverter operation.
Installing a Rear Panel
Before installing the inverter, secure the shipped rear panel to a wall.
Step 1 Remove the rear panel from the packaging box.
Step 2 Determine the positions for drilling holes using the rear panel.
RS 1.5/2.0/3.0 PV inverter with single MPPT input
RS 4.0/5.0/6.0 PV inverter with double MPPT input
The correct installation mode
The wrong installation mode

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Step 3 Level the hole positions using a level and mark the hole positions using a marker.
Step 4 Drill holes using a hammer drill and install expansion bolts, as shown in the figure below.
DANGER
Before drilling the hole in the wall, ensure that no electrical wiring and/or water piping inside the wall will be
damaged.
•Drill a hole in a marked position to a depth of 60 mm using a hammer drill with a Ф10 mm bit.
•Partially tighten an expansion bolt, insert it vertically into the hole and knock it completely into the hole using a rubber mallet.
Punch holes
Install expansion plugs
Step 5 Align the rear panel with the holes, insert the expansion bolts into the holes through the real panel and tighten them to a torque
of 2-2.5 Nm using a torque wrench.
level
Ø1 0 drillin g depth 60mm,：
torque 2-2.5N.m：

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Installing the Inverter
Follow the procedures described below:
Step 1 The installer must hold the handle at both sides of the inverter and then lift the inverter and place it standing.
Step 2 Mount the inverter on the rear panel and keep the two parts aligned with one another.
Step 3 Tighten the two hexagon screws at both sides of the inverter to a torque of 1.2 Nm and 3 Nm respectively. Screw specs for
1K-3.6K and 3K-6K are M4 and M6 respectively.
Mount on the rear panel
Tighten the screws at both sides

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ELECTRICAL INSTALLATION
Preliminary operations
•It is advisable to install a circuit breaker on the AC side (see “Recommended circuit breaker” in the technical specifications
table).
•Turn the DC switch to off.
•Open the AC switch downstream of the inverter.
DANGER
Before performing any electrical connections, ensure that both the DC and AC switches are OFF.
Otherwise, fatal injury can occur due to the high voltage generated by the AC and DC cables.
CAUTION
Grounding of the PV strings must obey the following prerequisites:
If an isolation transformer must be installed on the AC side of each inverter, ensure that the neutral wire of the isolation
transformer is disconnected from the PGND cable.
One isolation transformer goes with one PV inverter: do not install a single isolation transformer for multiple inverters; otherwise,
circulating current generated by the inverters will lead to operation failure.
Connecting Protection Ground (PGND) Cables
Preparation
The ground cable and OT terminals have to be prepared.
Ground cable: outdoor copper-core cables with 4 mm2cross-sectional area or more are recommended.
OT terminal: OT6~4 M4
NOTE
Proper grounding for the inverter helps to counter the impact of surge voltage and improve EMI performance.
Connect the PGND cable before connecting the AC and DC power cables and the communication cables.
NOTE
It is recommended that the ground cable be connected to a nearby ground position. For a system with multiple
inverters connected in parallel, connect the ground points of all inverters to ensure equipotential connections.
Wiring Procedures
Step 1 Remove an appropriate length of the insulation layer from the PGND cable using a wire stripper; this length must be longer
than that of the OT terminal’s crimping end by 2 mm–3 mm.
Step 2 Insert the exposed core wires into the crimping areas of the OT terminal and crimp them using hydraulic pliers.

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Step 3 Remove the ground screws from the ground points.
Step 4 Secure the PGND cable (done with steps 1 and 2) using the ground screw and tighten the screw to a torque of 1.2 Nm using
a socket wrench.
Connecting the AC Output Cables
Preparation
The AC power cable and AC terminals have been prepared.
AC power cable: outdoor copper-core cables are recommended. The following table describes the specifications.
Inverter model
Cable type
Cross-sectional area (mm2)
Cable outer diameter (mm)
Range
Recommended value
Range
Recommended value
1K–3.6K
outdoor cable
4–6
4
10–14
14
3K–6K
outdoor cable
6
WARNING
An independent circuit breaker must be installed on the AC side of each
inverter to ensure that the inverter can be safely disconnected from the power grid.
WARNING
Do not connect loads between the AC output terminals of the inverter and circuit breaker.