LogoFronius Backup Controller 3P-35A
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    • Contact
    • Legal Notice
    • General Terms & Conditions
    • Data Privacy Statement
    • 003-02062025
    • General information
      • Safety information
        • Explanation of warnings and safety instructions
        • Safety instructions and important information
        • Environmental conditions
        • Electromagnetic fields
        • EMC measures
      • General
        • Information on the device
        • How information is presented in the document
        • Target group
        • Data security
        • Copyright
      • Fronius Backup Controller
        • Intended use
        • Foreseeable misuse
        • Scope of supply
        • Explanation of symbols
        • Positioning
        • Recommended Fronius Smart Meter
      • Operating controls and connections
        • Connection area
        • Description of digital inputs/outputs (I/Os)
        • LED status indicator
    • Installation and Startup
      • Prerequisites for connecting
        • Requirements
        • Different cable types
        • Permitted cables for the electrical connection
        • Permitted cables for digital inputs/outputs (I/Os)
      • Installation
        • Safety
        • De-energizing all sides of the PV system
        • Installation
        • Connecting to the public grid
        • Connecting loads in the backup power circuit
        • Connecting the inverter in the backup power circuit
        • Connecting the neutral conductor for the Fronius Smart Meter (optional)
        • Connecting the data communication cable (Fronius GEN24)
        • Connecting the data communication cable (Fronius Symo Hybrid)
      • Commissioning
        • Putting the PV system into operation
        • General
        • Backup power - Configuring Full Backup
        • Testing backup power mode
      • Commissioning (Fronius Symo Hybrid)
        • Configuring backup power mode
        • CONFIG menu settings
        • Alternatives (Notstrom)-Setup wählen
        • Testing backup power mode
    • Appendix
      • Care, maintenance, and disposal
        • Cleaning
        • Maintenance
        • Disposal
      • Warranty provisions
        • Fronius manufacturer's warranty
      • Technical data
        • Fronius Backup Controller
          3P-35A
    • Circuit Diagrams
      • Appendix: Fronius Backup Controller 3-pin separation, e.g., Austria
      • Appendix: Fronius Backup Controller 3-pin separation, e.g., Austria (Fronius Symo Hybrid)
      • Appendix: Fronius Backup Controller 1-pin separation
    • Dimensions
      • Appendix: Fronius Backup Controller 3P-35A

    Fronius Backup Controller 3P-35A Operating instructions

    Operating controls and connections
    Installation
    Commissioning
    Technical data

    General information

    Safety information

    Explanation of warnings and safety instructions

    The warnings and safety instructions in these instructions are intended to protect people from possible injury and the product from damage.

    DANGER!

    Indicates an immediately dangerous situation

    Serious injury or death will result if appropriate precautions are not taken.

    Action step to escape the situation

    WARNING!

    Indicates a potentially dangerous situation

    Death or serious injury may result if appropriate precautions are not taken.

    Action step to escape the situation

    CAUTION!

    Indicates a potentially dangerous situation

    Minor or moderate injury may result if appropriate precautions are not taken.

    Action step to escape the situation

    NOTE!

    Indicates impaired work results and/or damage to the device and components

    The warnings and safety instructions are an integral part of these instructions and must always be observed to ensure the safe and proper use of the product.

    1. General information

    Safety information

    Explanation of warnings and safety instructions

    The warnings and safety instructions in these instructions are intended to protect people from possible injury and the product from damage.

    DANGER!

    Indicates an immediately dangerous situation

    Serious injury or death will result if appropriate precautions are not taken.

    Action step to escape the situation

    WARNING!

    Indicates a potentially dangerous situation

    Death or serious injury may result if appropriate precautions are not taken.

    Action step to escape the situation

    CAUTION!

    Indicates a potentially dangerous situation

    Minor or moderate injury may result if appropriate precautions are not taken.

    Action step to escape the situation

    NOTE!

    Indicates impaired work results and/or damage to the device and components

    The warnings and safety instructions are an integral part of these instructions and must always be observed to ensure the safe and proper use of the product.

    1. General information
    2. Safety information

    Explanation of warnings and safety instructions

    The warnings and safety instructions in these instructions are intended to protect people from possible injury and the product from damage.

    DANGER!

    Indicates an immediately dangerous situation

    Serious injury or death will result if appropriate precautions are not taken.

    Action step to escape the situation

    WARNING!

    Indicates a potentially dangerous situation

    Death or serious injury may result if appropriate precautions are not taken.

    Action step to escape the situation

    CAUTION!

    Indicates a potentially dangerous situation

    Minor or moderate injury may result if appropriate precautions are not taken.

    Action step to escape the situation

    NOTE!

    Indicates impaired work results and/or damage to the device and components

    The warnings and safety instructions are an integral part of these instructions and must always be observed to ensure the safe and proper use of the product.

    1. General information
    2. Safety information

    Safety instructions and important information

    The device has been manufactured in line with the state of the art and according to recognized safety standards.

    WARNING!

    Incorrect operation or misuse

    Serious to fatal injuries to the operator or third parties as well as damage to the device and other property of the operator may result.

    All persons involved in the commissioning, maintenance, and servicing of the device must be appropriately qualified and have knowledge of working with electrical installations.

    Read these operating instructions in full and follow them carefully and precisely.

    The operating instructions must always be kept to hand wherever the device is being used.

    IMPORTANT!
    In addition to the operating instructions, all applicable local rules and regulations regarding accident prevention and environmental protection must also be followed.

    IMPORTANT!
    Labels, warning notices, and safety symbols are located on the device. A description can be found in these operating instructions.

    IMPORTANT!

    All safety and danger notices on the device:
    • Must be kept in a legible state
    • Must not be damaged/marked
    • Must not be removed
    • Must not be covered, have anything stuck on them, or painted over

    WARNING!

    Tampered-with and non-functioning protection devices

    Serious to fatal injuries as well as damage to the device and other property of the operator may result.

    Never bypass or disable protection devices.

    Any protection devices that are not fully functional must be repaired by an authorized specialist before the device is switched on.

    WARNING!

    Loose, damaged, or under-dimensioned cables

    An electric shock can be fatal.

    Use undamaged, insulated, and adequately dimensioned cables.

    Fasten the cables according to the specifications in the operating instructions.

    Loose, damaged, or under-dimensioned cables must be repaired or replaced immediately by an authorized specialist.

    NOTE!

    Installations or modifications to the device

    The device may be damaged

    Do not carry out any alterations, installations, or modifications to the device without first obtaining the manufacturer's permission.

    Damaged components must be replaced.

    Only use original spare parts.

    1. General information
    2. Safety information

    Environmental conditions

    Operation or storage of the device outside the stipulated area will be deemed as not in accordance with the intended purpose.

    1. General information
    2. Safety information

    Electromagnetic fields

    During operation, due to the high electrical voltages and currents, local electromagnetic fields (EMF) occur in the environment around the inverter and the Fronius system components as well as in the area of the PV modules including the supply lines.

    In the case of exposure to humans, the required limit values are observed when the products are used in line with the intended use and the recommended distance of at least 20 cm is observed.

    If these limit values are complied with, according to current scientific knowledge, no health-endangering effects from EMF exposure are to be expected. If wearers of prostheses (implants, metal parts in and on the body) as well as active physical aids (pacemakers, insulin pumps, hearing aids, etc.) are in the vicinity of components of the PV system, they must consult with the responsible doctor regarding possible health risks.

    1. General information
    2. Safety information

    EMC measures

    In certain cases, even though a device complies with the standard limit values for emissions, it may affect the application area for which it was designed (e.g., when there is equipment that is susceptible to interference at the same location or if the site where the device is installed is close to either radio or television receivers). If this is the case, the operator is obliged to take action to rectify the situation.

    1. General information

    General

    Information on the device

    Technical data and markings are located on the Fronius Backup Controller. This information must be kept in a legible condition and must not be removed, covered, pasted or painted over. These must not be removed or painted over.

    The information is located on the right side of the Backup Controller.

    Labelling

    CE label – confirms compliance with applicable EU directives and regulations.

    WEEE marking – waste electrical and electronic equipment must be collected separately and recycled in an environmentally sound manner in accordance with the European Directive and national law.

    RCM marking – tested according to the requirements of Australia and New Zealand.

    1. General information
    2. General

    Information on the device

    Technical data and markings are located on the Fronius Backup Controller. This information must be kept in a legible condition and must not be removed, covered, pasted or painted over. These must not be removed or painted over.

    The information is located on the right side of the Backup Controller.

    Labelling

    CE label – confirms compliance with applicable EU directives and regulations.

    WEEE marking – waste electrical and electronic equipment must be collected separately and recycled in an environmentally sound manner in accordance with the European Directive and national law.

    RCM marking – tested according to the requirements of Australia and New Zealand.

    1. General information
    2. General

    How information is presented in the document

    The conventions regarding how information is presented in the document, which are set out below, have been defined in order to increase the readability and comprehensibility of the document.

    Application notes

    IMPORTANT! Indicates application notes and other useful information. It does not indicate a harmful or dangerous situation.

    Software

    Software functions and elements of a graphical user interface (e.g., buttons, menu items) are highlighted in the text with this mark up.

    Example: Click Save.

    Instructions for action

    1Action steps are displayed with consecutive numbering.
    ✓This symbol indicates the result of the action step or the entire instruction.
    1. General information
    2. General

    Target group

    This document provides detailed information and instructions to ensure that all users can use the device safely and efficiently.

    • The information is intended for the following groups of people:
      • Technical specialists: People with appropriate qualifications and fundamental electronic and mechanical knowledge, who are responsible for the installation, operation, and maintenance of the device.
      • End users: People that use the device in daily operation and want to understand its basic functions.
    • Regardless of any qualifications, only perform the activities listed in this document.
    • All persons involved in the commissioning, maintenance, and servicing of the device must be appropriately qualified and have knowledge of working with electrical installations.
    • The definition of professional qualifications and their applicability are subject to national law.
    1. General information
    2. General

    Data security

    With regard to data security, the user is responsible for:
    • Backing up any changes made to the factory settings
    • Saving and storing personal settings

    NOTE!

    Observe the following points for safe operation:

    Operate inverters and system components on a private, secure network.

    Keep the network devices (e.g., WiFi routers) up to date with the latest technology.

    Keep the software and/or firmware updated.

    Use a wired network to ensure a stable data connection.

    The optional communication protocol Modbus TCP/IP1) is an unsecured interface. Only use Modbus TCP/IP if no other secured data communication protocol (MQTT2)) is possible (e.g., compatibility with older Smart Meters).

    1) TCP/IP - Transmission Control Protocol/Internet Protocol
    2) MQTT - Message Queueing Telemetry Protocol

    1. General information
    2. General

    Copyright

    Copyright of these operating instructions remains with the manufacturer.

    Text and illustrations were accurate at the time of printing, subject to change.
    We are grateful for suggestions for improvement and information on any discrepancies in the operating instructions.

    1. General information

    Fronius Backup Controller

    Intended use

    The Fronius Backup Controller is a fixed piece of equipment designed for use in public grids with TN-C-S/TN-S systems. Its main function is to automatically and securely disconnect all connected loads and generators from the public grid in the event of a grid failure or grid malfunction in accordance with the specifications of the grid operator. As soon as grid stability has been restored, the loads and generators are automatically reconnected to the public grid.

    1. Application: The Fronius Backup Controller is required for systems with storage batteries to enable automatic backup power switching.
    2. Installation: The Fronius Backup Controller is installed either on an indoor DIN rail or in special enclosures with corresponding IP protection, depending on the environmental conditions.
    3. Safety precautions: In conjunction with a Fronius Smart Meter, corresponding back-up fuses must be selected to suit the cable cross-sections of the copper conductors and the maximum current of the Fronius Backup Controller (see Fronius Backup Controller3P-35A on page (→)).
    4. Intended use: The Fronius Backup Controller must only be operated in accordance with the specifications in the enclosed documentation and in accordance with local laws, regulations, provisions, standards, and within the limits of technical possibilities. Any use of the product other than as described under intended use shall be deemed to be not in accordance with intended use.
    5. Documentation: The available documentation forms part of the product and must be read, observed, and kept in good condition. It must also be accessible at all times at the place of installation. The available documents do not replace regional, state, provincial, or national laws, or regulations or standards that apply to the installation, electrical safety, and use of the product. Fronius International GmbH assumes no responsibility for compliance with or non-compliance with these laws or regulations in connection with the installation of the product.
    6. Interventions and modifications: Interventions in the Fronius Backup Controller, e.g., modifications and alterations, are not permitted. Unauthorized interventions will void the warranty and warranty claims and, as a rule, void the user's authority to operate the equipment.
    1. General information
    2. Fronius Backup Controller

    Intended use

    The Fronius Backup Controller is a fixed piece of equipment designed for use in public grids with TN-C-S/TN-S systems. Its main function is to automatically and securely disconnect all connected loads and generators from the public grid in the event of a grid failure or grid malfunction in accordance with the specifications of the grid operator. As soon as grid stability has been restored, the loads and generators are automatically reconnected to the public grid.

    1. Application: The Fronius Backup Controller is required for systems with storage batteries to enable automatic backup power switching.
    2. Installation: The Fronius Backup Controller is installed either on an indoor DIN rail or in special enclosures with corresponding IP protection, depending on the environmental conditions.
    3. Safety precautions: In conjunction with a Fronius Smart Meter, corresponding back-up fuses must be selected to suit the cable cross-sections of the copper conductors and the maximum current of the Fronius Backup Controller (see Fronius Backup Controller3P-35A on page (→)).
    4. Intended use: The Fronius Backup Controller must only be operated in accordance with the specifications in the enclosed documentation and in accordance with local laws, regulations, provisions, standards, and within the limits of technical possibilities. Any use of the product other than as described under intended use shall be deemed to be not in accordance with intended use.
    5. Documentation: The available documentation forms part of the product and must be read, observed, and kept in good condition. It must also be accessible at all times at the place of installation. The available documents do not replace regional, state, provincial, or national laws, or regulations or standards that apply to the installation, electrical safety, and use of the product. Fronius International GmbH assumes no responsibility for compliance with or non-compliance with these laws or regulations in connection with the installation of the product.
    6. Interventions and modifications: Interventions in the Fronius Backup Controller, e.g., modifications and alterations, are not permitted. Unauthorized interventions will void the warranty and warranty claims and, as a rule, void the user's authority to operate the equipment.
    1. General information
    2. Fronius Backup Controller

    Foreseeable misuse

    The backup power switching is not suitable to supply loads that require an uninterruptible supply (e.g., IT networks, life-sustaining medical devices).

    1. General information
    2. Fronius Backup Controller

    Scope of supply

    Pack contents
    (1)
    Fronius Backup Controller
    (2)
    Quick Start Guide
    (3)
    Backup power warning notice
    1. General information
    2. Fronius Backup Controller

    Explanation of symbols

     

    PV module
    Generates direct current

     

    Fronius GEN24 inverter
    Converts direct current into alternating current and charges the battery (battery charging is only possible with Fronius GEN24 Plus inverters). The integrated system monitoring enables the inverter to be integrated into a network by means of WiFi.

     

    Fronius Symo Hybrid inverter
    Converts the direct current into alternating current and charges the battery. The integrated system monitoring enables the inverter to be integrated into a network by means of WiFi.

     

    Fronius Backup Controller
    Automatically and securely disconnects all connected loads and generators from the public grid in the event of a grid failure or grid malfunction in accordance with the specifications of the grid operator. As soon as grid stability has been restored, the loads and generators are automatically reconnected to the public grid.

     

    Inverter in the system
    e.g., Fronius Primo, Fronius Symo

     

    Primary meter
    Records the system's load curve and provides measurement data for energy profiling in Fronius Solar.web. The primary meter also controls the dynamic power of feeding in.

     

    Utility meter
    Measures the measurement data relevant for billing amounts of energy (in particular kilowatt hours of energy sourced from the grid and energy fed into the grid). Based on the relevant billing data, the electricity retailer will invoice for the energy sourced from the grid and the purchaser of the surplus energy will reimburse the energy fed into the grid.

     

    Grid
    Supplies the loads in the system if insufficient power is being generated by the PV modules or supplied by the battery.

     

    Battery
    Is coupled to the inverter on the direct current side, and stores electrical energy.

     

    Loads in the system
    e.g., washing machine, lamps, TV

    1. General information
    2. Fronius Backup Controller

    Positioning

    The Fronius Backup Controller must be installed in the backup power circuit of the photovoltaic system.

    NOTE!

    Other inverters/generators in the house

    Only 1 hybrid inverter may be installed in the backup power circuit of the PV system. Failure to follow this specification may result in damage to the PV system.

    Install other inverters/generators outside the backup power circuit.

    Alternatively, install a dedicated backup power circuit for these devices.

    Fronius GEN24 Inverter

    The Backup Controller is installed in the backup power circuit.

    Fronius Symo Hybrid inverter

    The Backup Controller is installed in the backup power circuit.
    1. General information
    2. Fronius Backup Controller

    Recommended Fronius Smart Meter

    Device name

    Item number

    Fronius Smart Meter IP

    42,0411,0347

    Fronius Smart Meter 63A-3

    43,0001,1473

    Fronius Smart Meter TS 65A-3

    43,0001,0044

    1. General information

    Operating controls and connections

    Connection area

    Overview of the connection area.
    (1)
    1-pin push-in terminal for the neutral conductor connection to the Fronius Smart Meter (max. 1 A).
    (2)
    Push-in terminal for digital inputs/outputs (I/Os).
    (3)
    3-pin push-in terminal for the supply from the public grid.
    (4)
    8-pin push-in terminal for loads/generators in the backup power circuit.
    1. General information
    2. Operating controls and connections

    Connection area

    Overview of the connection area.
    (1)
    1-pin push-in terminal for the neutral conductor connection to the Fronius Smart Meter (max. 1 A).
    (2)
    Push-in terminal for digital inputs/outputs (I/Os).
    (3)
    3-pin push-in terminal for the supply from the public grid.
    (4)
    8-pin push-in terminal for loads/generators in the backup power circuit.
    1. General information
    2. Operating controls and connections

    Description of digital inputs/outputs (I/Os)

    I/O pin

    Parameter

    Description

    IO 0

    Enable backup power locking

    Before the inverter switches to backup power mode, the pin IO 0 must be active (value = 1).

    IN 6

    Grid relay open feedback

    If the mains voltage is too low or the relay K3 is closed and therefore the relays K1, K2, and K4 are open, the auxiliary contacts of the mains isolation relays are closed and the pin IN 6 is active (value = 1).

    IN 7

    Locking feedback

    When relay K3 is activated, the auxiliary contact of relay K3 closes and pin IN 7 is active (value = 1). The inverter receives feedback that relay K3 is closed.

    1. General information
    2. Operating controls and connections

    LED status indicator

    The LED status indicator shows the operating status.

    Symbol

    LED status

    Description

    Grid
    LED

    Lights up green

    The "Grid" LED indicates that all connected loads and generators in the backup power circuit are being supplied by or are connected to the public grid.

    Full Backup
    LED

    Lights up blue

    The "Full Backup" LED indicates that all connected loads and generators in the backup power circuit are safely disconnected from the public grid and that the Full Backup power supply is active.

    Installation and Startup

    Prerequisites for connecting

    Requirements

    The following components must be installed in the switch cabinet to permit the safe operation of the Fronius Backup Controller:
    • Upstream overcurrent protection as specified in chapter Fronius Backup Controller3P-35A on page (→).
    • A surge protection device (SPD) as specified in chapter Fronius Backup Controller3P-35A on page (→).
    1. Installation and Startup

    Prerequisites for connecting

    Requirements

    The following components must be installed in the switch cabinet to permit the safe operation of the Fronius Backup Controller:
    • Upstream overcurrent protection as specified in chapter Fronius Backup Controller3P-35A on page (→).
    • A surge protection device (SPD) as specified in chapter Fronius Backup Controller3P-35A on page (→).
    1. Installation and Startup
    2. Prerequisites for connecting

    Requirements

    The following components must be installed in the switch cabinet to permit the safe operation of the Fronius Backup Controller:
    • Upstream overcurrent protection as specified in chapter Fronius Backup Controller3P-35A on page (→).
    • A surge protection device (SPD) as specified in chapter Fronius Backup Controller3P-35A on page (→).
    1. Installation and Startup
    2. Prerequisites for connecting

    Different cable types

    Single-core

    Multi-stranded

    Fine-stranded

    Fine-stranded with ferrule and collar

    Fine-stranded with ferrule without collar

    Single-core cable type
    Multi-stranded cable type
    Fine-stranded cable type
    Fine-stranded with ferrule and collar cable type
    Fine-stranded with ferrule without collar cable type
    1. Installation and Startup
    2. Prerequisites for connecting

    Permitted cables for the electrical connection

    Round copper conductors can be connected to the terminals as described below.

    Push-in terminals for the supply from the public grid.*
    Select a sufficiently large cable cross-section based on the actual connected output.

    Single-core cable type
    Multi-stranded cable type
    Fine-stranded cable type
    Fine-stranded cable type with ferrule and collar
    Fine-stranded cable type with ferrule without collar

    2.5 - 10 mm2

    2.5 - 10 mm2

    2.5 - 10 mm2

    2.5 - 6 mm2

    2.5 - 6 mm2

    Push-in terminals for the loads/generators in the backup power circuit.*
    Select a sufficiently large cable cross-section based on the actual connected output.

    Single-core cable type
    Multi-stranded cable type
    Fine-stranded cable type
    Fine-stranded cable type with ferrule and collar
    Fine-stranded cable type with ferrule without collar

    2.5 - 10 mm2

    2.5 - 10 mm2

    2.5 - 10 mm2

    2.5 - 6 mm2

    2.5 - 6 mm2

    Push-in terminal for the neutral conductor connection to the Fronius Smart Meter (max. 1 A)

    Single-core cable type
    Multi-stranded cable type
    Fine-stranded cable type
    Fine-stranded cable type with ferrule and collar
    Fine-stranded cable type with ferrule without collar

    1 - 4 mm2

    1 - 4 mm2

    1 - 4 mm2

    1 - 2.5 mm2

    1 - 2.5 mm2

    1. Installation and Startup
    2. Prerequisites for connecting

    Permitted cables for digital inputs/outputs (I/Os)

    Round copper conductors can be connected to the push-in terminals for digital inputs/outputs (I/Os) as described below.

    IO connections with push-in terminal

    Max.
    distance

    Stripping length

    Single-core cable type
    Multi-stranded cable type
    Fine-stranded cable type with ferrule and collar
    Fine-stranded cable type with ferrule without collar

    Cable recommendation

    30 m *
    32 yd *

    10 mm 
    0.39 inch

    0.14 - 1.5 mm2
    AWG 26 - 16

    0.14 - 1.5 mm2
    AWG 26 - 16

    0.14 - 1 mm2
    AWG 26 - 18

    0.14 - 1.5 mm2
    AWG 26 - 16

    Single conductors possible

    *
    The maximum cable length between the inverter and the Backup Controller must not exceed 30 m (32 yd). Fronius recommends using at least CAT 5 STP (shielded twisted pair) cables.
    1. Installation and Startup

    Installation

    Safety

    WARNING!

    Danger from short circuits due to foreign bodies in the housing.

    An electric shock can lead to serious injury or death.

    Cover vents during installation.

    WARNING!

    Danger due to incorrect operation and incorrectly performed work.

    This can result in serious injury and damage to property.

    Only trained service technicians who have received training from the respective inverter or battery manufacturer are authorized to perform commissioning, maintenance, and service activities for inverters and batteries, and only within the scope of the technical regulations.

    Read the installation instructions and operating instructions from the respective manufacturer before installing and commissioning the equipment.

    WARNING!

    Danger from mains voltage and DC voltage from PV modules that are exposed to light, as well as batteries.

    This can result in serious injury and damage to property.

    All connection, maintenance, and service work should only be carried out when the AC and DC sides have been disconnected from the inverter and battery, and are de-energized.

    Only an authorized electrical engineer is permitted to connect this equipment to the public grid.

    WARNING!

    Danger from damaged and/or contaminated terminals.

    This can result in serious injury and damage to property.

    Prior to connection work, check the terminals for damage and contamination.

    Remove any contamination while the equipment is de-energized.

    Have defective terminals repaired by an authorized specialist.

    1. Installation and Startup
    2. Installation

    Safety

    WARNING!

    Danger from short circuits due to foreign bodies in the housing.

    An electric shock can lead to serious injury or death.

    Cover vents during installation.

    WARNING!

    Danger due to incorrect operation and incorrectly performed work.

    This can result in serious injury and damage to property.

    Only trained service technicians who have received training from the respective inverter or battery manufacturer are authorized to perform commissioning, maintenance, and service activities for inverters and batteries, and only within the scope of the technical regulations.

    Read the installation instructions and operating instructions from the respective manufacturer before installing and commissioning the equipment.

    WARNING!

    Danger from mains voltage and DC voltage from PV modules that are exposed to light, as well as batteries.

    This can result in serious injury and damage to property.

    All connection, maintenance, and service work should only be carried out when the AC and DC sides have been disconnected from the inverter and battery, and are de-energized.

    Only an authorized electrical engineer is permitted to connect this equipment to the public grid.

    WARNING!

    Danger from damaged and/or contaminated terminals.

    This can result in serious injury and damage to property.

    Prior to connection work, check the terminals for damage and contamination.

    Remove any contamination while the equipment is de-energized.

    Have defective terminals repaired by an authorized specialist.

    1. Installation and Startup
    2. Installation

    De-energizing all sides of the PV system

    1

    Switch off the house connection fuse and the automatic circuit breaker. Set the DC disconnector to the "off" switch position.

    2

    Switch off the battery connected to the inverter.

    Wait for the capacitors of the inverter to discharge (2 minutes).

    1. Installation and Startup
    2. Installation

    Installation

    Mount the device on a 35 mm DIN rail.

    The Fronius Backup Controller can be mounted on a 35 mm DIN rail. The housing comprises 8 modules according to DIN 43880 and conforms to unit size 2.

    1. Installation and Startup
    2. Installation

    Connecting to the public grid

    WARNING!

    Danger from loose and/or incorrectly clamped single conductors in the terminal.

    This can result in serious injury and damage to property.

    Only connect one single conductor in the slot provided for each terminal.

    Check that the single conductors are secure in the terminal.

    Make sure that the single conductor has been fully inserted into the terminal and that no single wires are protruding out of the terminal.

    1

    Strip the insulation of the single conductors by 12 mm.
    Select the cable cross-section in accordance with the instructions in Permitted cables for the electrical connection from page (→).

    2

    Lift the operating levers of the terminals to open. Insert the stripped single conductors into the slot provided in the terminal, in each case as far as it will go.

    3

    Close the terminal operating levers until they engage.

    1. Installation and Startup
    2. Installation

    Connecting loads in the backup power circuit

    WARNING!

    Danger from loose and/or incorrectly clamped single conductors in the terminal.

    This can result in serious injury and damage to property.

    Only connect one single conductor in the slot provided for each terminal.

    Check that the single conductors are secure in the terminal.

    Make sure that the single conductor has been fully inserted into the terminal and that no single wires are protruding out of the terminal.

    1

    Strip the insulation of the single conductors by 12 mm.
    Select the cable cross-section in accordance with the instructions in Permitted cables for the electrical connection from page (→).

    2

    Lift the operating levers of the terminals to open. Insert the stripped single conductors into the slot provided in the terminal, in each case as far as it will go.

    IMPORTANT!
    The neutral conductor must be connected to the public grid.

    3

    Close the terminal operating levers until they engage.

    1. Installation and Startup
    2. Installation

    Connecting the inverter in the backup power circuit

    WARNING!

    Danger from loose and/or incorrectly clamped single conductors in the terminal.

    This can result in serious injury and damage to property.

    Only connect one single conductor in the slot provided for each terminal.

    Check that the single conductors are secure in the terminal.

    Make sure that the single conductor has been fully inserted into the terminal and that no single wires are protruding out of the terminal.

    1

    Strip the insulation of the single conductors by 12 mm.
    Select the cable cross-section in accordance with the instructions in Permitted cables for the electrical connection from page (→).

    2

    Lift the operating levers of the terminals to open. Insert the stripped single conductors into the slot provided in the terminal, in each case as far as it will go.

    IMPORTANT!
    The neutral conductor must be connected to the public grid.

    3

    Close the terminal operating levers until they engage.

    1. Installation and Startup
    2. Installation

    Connecting the neutral conductor for the Fronius Smart Meter (optional)

    WARNING!

    Danger from loose and/or incorrectly clamped single conductors in the terminal.

    This can result in serious injury and damage to property.

    Only connect one single conductor in the slot provided for each terminal.

    Check that the single conductors are secure in the terminal.

    Make sure that the single conductor has been fully inserted into the terminal and that no single wires are protruding out of the terminal.

    1

    Strip the insulation of the single conductors by 10 mm.
    Select the cable cross-section in accordance with the instructions in Permitted cables for the electrical connection from page (→).

    2

    Lift the operating levers of the terminals to open. Insert the stripped single conductor into the slot provided in the terminal as far as it will go.

    3

    Close the operating lever of the terminal until it engages.

    1. Installation and Startup
    2. Installation

    Connecting the data communication cable (Fronius GEN24)

    WARNING!

    Danger due to a short circuit between the single conductor of the shielding and live components.

    This can result in serious injury and damage to property.

    Insulate unused single conductors of the shielding with a shrink sleeve.

    NOTE!

    Danger from external power supply

    If the data communication area is connected to a powerful external power supply, the Backup Controller may be damaged.

    The external supply must not exceed a voltage of 12 V (+/- 10%).

    Observe the following points when connecting the data communication cable.
    • Use network cables of type CAT5 STP or higher.
    • Use a twisted cable pair for corresponding data cables.
    • Use double insulated or sheathed data cables when near bare conductors.
    • Use shielded twisted pair cables to avoid interference.
    Connection overview of the data communication cables between the Fronius Smart Meter, Fronius Backup Controller, and Fronius GEN24 inverter.
    1. Installation and Startup
    2. Installation

    Connecting the data communication cable (Fronius Symo Hybrid)

    WARNING!

    Danger due to a short circuit between the single conductor of the shielding and live components.

    This can result in serious injury and damage to property.

    Insulate unused single conductors of the shielding with a shrink sleeve.

    Observe the following points when connecting the data communication cable.
    • Use network cables of type CAT5 STP or higher.
    • Use a twisted cable pair for corresponding data cables.
    • Use double insulated or sheathed data cables when near bare conductors.
    • Use shielded twisted pair cables to avoid interference.
    Connection overview of the data communication cables between the Fronius Smart Meter, Fronius Backup Controller, and Fronius Symo Hybrid inverter.
    1. Installation and Startup

    Commissioning

    Putting the PV system into operation

    1

    Switch on the battery connected to the inverter.

    2

    Set the DC disconnector to the "on" switch position. Turn on the automatic circuit breaker.

    1. Installation and Startup
    2. Commissioning

    Putting the PV system into operation

    1

    Switch on the battery connected to the inverter.

    2

    Set the DC disconnector to the "on" switch position. Turn on the automatic circuit breaker.

    1. Installation and Startup
    2. Commissioning

    General

    IMPORTANT!
    Settings in the Device configuration > Functions and I/Os menu item may only be implemented by staff trained to do so! The service password must be entered for the Device configuration menu item.

    1. Installation and Startup
    2. Commissioning

    Backup power - Configuring Full Backup

    1Call up the user interface of the inverter.
    - Open web browser.
    - In the address bar of the browser, enter the IP address
    (WiFi: 192.168.250.181, LAN: 169.254.0.180) or enter and confirm the host and domain name of the inverter.
    ✓The user interface of the inverter is displayed.
    2Log in to the login area with user Technician and the technician password.
    3Activate the Backup Power function in the Device Configuration > Functions and I/Os menu area.
    4Select Full Backup mode in the Backup power mode drop-down list.
    5Click the Save button to save the settings.
    ✓The Full Backup power mode has been configured.
    1. Installation and Startup
    2. Commissioning

    Testing backup power mode

    Testing backup power mode is recommended:
    • During the initial installation and configuration
    • After working on the switch cabinet
    • During ongoing operation (recommendation: at least once a year)

    For test mode, a battery charge of min. 30% is recommended.

    A description on how to run test mode can be found in the backup power checklist (https://www.fronius.com/en/search-page, item number: 42,0426,0365).

    1. Installation and Startup

    Commissioning (Fronius Symo Hybrid)

    Configuring backup power mode

    WARNING!

    Danger due to residual current in the backup power circuit

    An electric shock can cause serious injury or death. In addition, damage to the device and the connected components of the PV system can occur.

    Install a residual current circuit breaker in the backup power circuit in accordance with local regulations and/or national guidelines.

    1Open the Fronius Datamanager 2.0 user interface.
    - Open web browser.
    - In the address bar of the browser, enter the IP address
    or the host and domain name of the Fronius Datamanager 2.0 and confirm.
    ✓The Fronius Datamanager 2.0 user interface is displayed.
    2Log in to the login area with the Service user and the service password.
    3In the IO Control menu area for the Backup Power function, set the pin assignment as follows:

    Function

    Description

    Default pin

    Enable backup power locking

    Output, triggers disconnection from the mains (contactor)

    0

    Feedback locking (optional)

    Input, gives feedback on whether locking is active

    5

    Backup power request

    Input, triggers backup power mode

    4

    4Click the Save button to save the settings.
    ✓Backup power mode is activated and configured.
    1. Installation and Startup
    2. Commissioning (Fronius Symo Hybrid)

    Configuring backup power mode

    WARNING!

    Danger due to residual current in the backup power circuit

    An electric shock can cause serious injury or death. In addition, damage to the device and the connected components of the PV system can occur.

    Install a residual current circuit breaker in the backup power circuit in accordance with local regulations and/or national guidelines.

    1Open the Fronius Datamanager 2.0 user interface.
    - Open web browser.
    - In the address bar of the browser, enter the IP address
    or the host and domain name of the Fronius Datamanager 2.0 and confirm.
    ✓The Fronius Datamanager 2.0 user interface is displayed.
    2Log in to the login area with the Service user and the service password.
    3In the IO Control menu area for the Backup Power function, set the pin assignment as follows:

    Function

    Description

    Default pin

    Enable backup power locking

    Output, triggers disconnection from the mains (contactor)

    0

    Feedback locking (optional)

    Input, gives feedback on whether locking is active

    5

    Backup power request

    Input, triggers backup power mode

    4

    4Click the Save button to save the settings.
    ✓Backup power mode is activated and configured.
    1. Installation and Startup
    2. Commissioning (Fronius Symo Hybrid)

    CONFIG menu settings

    1Press the "Menu" key on the inverter

     

    The menu level is displayed.

    2Press the unassigned "Menu / Esc"
    key 5 times  

    Access Code is displayed in the CODE menu; the first digit starts flashing.
    The access code for the CONFIG menu is: 39872

    3Select the value for the first digit of the code with the keys
    4Press the "Enter" key

    The second digit flashes.

    5Repeat steps 3 and 4 until the entire access code (39872) flashes.
    6Press the "Enter" key

     

    The first parameter of the CONFIG menu is displayed.

    1. Installation and Startup
    2. Commissioning (Fronius Symo Hybrid)

    Alternatives (Notstrom)-Setup wählen

    The setups with the designation "EmergencyPower" are available as "Alternative (emergency power) setups":
    • EmergencyPower 50Hz: for all countries with a nominal frequency of 50 Hz
    • EmergencyPower 60Hz: for all countries with a nominal frequency of 60 Hz
    1Use the 'Up' and 'Down' keys to select the Alternative (emergency power) setup
    2Press the ‘Enter’ key.
    1. Installation and Startup
    2. Commissioning (Fronius Symo Hybrid)

    Testing backup power mode

    Testing backup power mode is recommended:
    • During the initial installation and configuration
    • After working on the switch cabinet
    • During ongoing operation (recommendation: at least once a year)

    For test mode, a battery charge of min. 30% is recommended.

    A description on how to run test mode can be found in the backup power checklist (https://www.fronius.com/en/search-page, item number: 42,0426,0365).

    Appendix

    Care, maintenance, and disposal

    Cleaning

    Clean the Backup Controller as required with a damp cloth.
    Do not use cleaning agents, abrasives, solvents or similar to clean the Backup Controller.

    1. Appendix

    Care, maintenance, and disposal

    Cleaning

    Clean the Backup Controller as required with a damp cloth.
    Do not use cleaning agents, abrasives, solvents or similar to clean the Backup Controller.

    1. Appendix
    2. Care, maintenance, and disposal

    Cleaning

    Clean the Backup Controller as required with a damp cloth.
    Do not use cleaning agents, abrasives, solvents or similar to clean the Backup Controller.

    1. Appendix
    2. Care, maintenance, and disposal

    Maintenance

    Maintenance and service work may only be carried out by qualified technical personnel.

    1. Appendix
    2. Care, maintenance, and disposal

    Disposal

    Waste electrical and electronic equipment must be collected separately and recycled in an environmentally sound manner in accordance with the European Directive and national law. Used equipment must be returned to the distributor or through a local authorized collection and disposal system. Proper disposal of the used device promotes sustainable recycling of resources and prevents negative effects on health and the environment.

    Packaging materials
    • Collect separately
    • Observe local regulations
    • Crush cardboard boxes
    1. Appendix

    Warranty provisions

    Fronius manufacturer's warranty

    Detailed, country-specific warranty conditions are available at www.fronius.com/solar/warranty.

    To obtain the full warranty period for your newly installed Fronius product, please register at www.solarweb.com.

    1. Appendix
    2. Warranty provisions

    Fronius manufacturer's warranty

    Detailed, country-specific warranty conditions are available at www.fronius.com/solar/warranty.

    To obtain the full warranty period for your newly installed Fronius product, please register at www.solarweb.com.

    1. Appendix

    Technical data

    Fronius Backup Controller
    3P-35A

    General data

    Grid configuration

    TN-S/TN-C-S

    Housing

    8 modules according to DIN 43880

    Mounting

    35 mm DIN rail

    Weight

     625 g

    Protection class

    IP20

    Fault Ride Through (FRT)

    According to EN 50549-10

    Short-circuit breaking capacity

    Class PC

    Self-consumption

    <5 W

    Environmental conditions

    Permitted ambient temperature

    -20 to +60 °C

    Permissible humidity

    50% relative humidity at 40 °C

    Max. altitude

    2000 m

    Vibrations

    Not permitted

    Rated values

    Nominal voltage

    230/400 V 3-pole or 3-pole + N

    Nominal current

    35 A

    Max. permissible fuses

    35 A gG fuse
    35 A automatic circuit breaker

    Duty cycle

    100% at AC-32

    Rated power

    24 kVA

    Grid frequency

    50 Hz

    Power loss (at nominal current)

    15 W

    Overvoltage category

    III

    Electromagnetic compatibility

    Interference immunity

    According to EN 61000-6-2 2019-12-01

    Emissions

    According to EN 61000-6-3 2020-07

    1. Appendix
    2. Technical data

    Fronius Backup Controller
    3P-35A

    General data

    Grid configuration

    TN-S/TN-C-S

    Housing

    8 modules according to DIN 43880

    Mounting

    35 mm DIN rail

    Weight

     625 g

    Protection class

    IP20

    Fault Ride Through (FRT)

    According to EN 50549-10

    Short-circuit breaking capacity

    Class PC

    Self-consumption

    <5 W

    Environmental conditions

    Permitted ambient temperature

    -20 to +60 °C

    Permissible humidity

    50% relative humidity at 40 °C

    Max. altitude

    2000 m

    Vibrations

    Not permitted

    Rated values

    Nominal voltage

    230/400 V 3-pole or 3-pole + N

    Nominal current

    35 A

    Max. permissible fuses

    35 A gG fuse
    35 A automatic circuit breaker

    Duty cycle

    100% at AC-32

    Rated power

    24 kVA

    Grid frequency

    50 Hz

    Power loss (at nominal current)

    15 W

    Overvoltage category

    III

    Electromagnetic compatibility

    Interference immunity

    According to EN 61000-6-2 2019-12-01

    Emissions

    According to EN 61000-6-3 2020-07

    Circuit Diagrams

    Appendix: Fronius Backup Controller 3-pin separation, e.g., Austria

    1. Circuit Diagrams

    Appendix: Fronius Backup Controller 3-pin separation, e.g., Austria

    1. Circuit Diagrams

    Appendix: Fronius Backup Controller 3-pin separation, e.g., Austria (Fronius Symo Hybrid)

    1. Circuit Diagrams

    Appendix: Fronius Backup Controller 1-pin separation

    Dimensions

    Appendix: Fronius Backup Controller 3P-35A

    1. Dimensions

    Appendix: Fronius Backup Controller 3P-35A