Protection functions

Safety for plant, building and grid

REFUsol inverters continuously monitor strings, earth faults, residual current and the grid, and shut down safely in the event of a fault. Arc fault detection is integrated in the utility inverters and optional in the C&I series.

Request a projectSuitable products

What matters in protection functions

A PV plant operates with high DC voltages for decades, often on roofs with people and goods underneath. Faults such as arcs, earth faults or overvoltages must be detected early.

At the same time, grid operators require inverters to shut down safely in the event of a grid failure and not to keep feeding in unintentionally.

Challenges

Arc fault detection

AFCI detects dangerous arcs on the DC side and shuts down, tested to IEC 63027 for the 250K-5T and 360K-6T.

Surge protection

Type II surge protection on the DC and AC side on all inverters, with Type I + II optional on the DC side in the C&I series.

Grid protection

Anti-islanding to IEC 62116: if the grid fails, the inverter disconnects safely.

Earth fault and residual current

Earth fault monitoring and residual current monitoring (RCMU) in every unit, plus string monitoring in the utility inverters.

How REFU delivers protection

The protection functions are integrated in the inverter and work without additional devices. With REFUview, operators keep track of the status of every inverter.

REFUsol 360K-6TREFUsol 250K-5TREFUsol 125K-10TREFUlinkREFUviewGrid operator / control room

IEC 63027

AFCI tested (250K-5T, 360K-6T)

Type I + II

DC surge protection (optional, C&I series)

IP66

Protection rating of utility inverters

C5-M

Corrosion protection (250K-5T, 360K-6T)

Suitable products

Utility inverters

REFUsol 360K-6T

Rugged for large solar parks in harsh conditions

AC power
363 kW
MPPTs
6
max. efficiency
99.01 %

REFUsol 250K-5T

For solar parks with full power even in hot conditions

AC power
250 kW
MPPTs
5
max. efficiency
99.01 %

C&I inverters

REFUsol 125K-10T

More power for large commercial and smaller ground-mounted systems

AC power
110 kW
MPPTs
10
max. efficiency
98.6 %

REFUsol 110K-10T

For complex system layouts with many module arrays

AC power
100 kW
MPPTs
10
max. efficiency
98.6 %

REFUsol 50K-4T

Powerful for large commercial and industrial rooftops

AC power
50 kW
MPPTs
4
max. efficiency
98.8 %

REFUsol 33K-3T

More power for mid-size commercial systems and repowering

AC power
33 kW
MPPTs
3
max. efficiency
98.6 %

REFUsol 25K-3T

For replacement in existing commercial systems

AC power
25 kW
MPPTs
3
max. efficiency
98.6 %

REFUsol 20K-2T

Compact entry model for smaller commercial rooftops

AC power
20 kW
MPPTs
2
max. efficiency
98.6 %

REFUsol 20K-3T

Flexible for commercial rooftops with several roof areas

AC power
20 kW
MPPTs
3
max. efficiency
98.6 %

Your benefit as …

EPCs & general contractors

  • Datasheets, certificates and manuals in the download centre

    Datasheets, unit certificates, declarations of conformity and manuals are all in one place in the download centre, always in the current version.

  • Personal contacts in sales and engineering

    For system design, quotations and detailed technical questions, you talk directly to our sales team and our engineers, including for large solar parks.

  • Scalable with REFUlink and REFUview

    REFUlink connects up to 60 inverters to the control room and the grid operator, while REFUview brings all operating data together. The system grows with your plant.

Installers & electrical contractors

  • Easy commissioning

    Many models can be set up via app over Bluetooth directly at the inverter. This saves time when commissioning on commercial rooftops.

  • Technical support from Germany

    For questions about installation, settings or error messages, you can reach our technical support in Germany, personally and without detours.

  • Fits new and existing systems

    REFUsol inverters can be integrated into new and existing PV plants, and via REFUlink also together with older generations of REFU inverters.

Operators & investors

  • Real-time monitoring with REFUview

    REFUview shows the status, output and yield of your PV plant in real time, on your computer and on your smartphone. Spot deviations early and protect your yield.

  • Data hosting in Germany

    Your plant data is hosted and processed in Germany. This makes data protection and data sovereignty easier, especially for operators of critical infrastructure.

  • Technical support from Germany

    For questions about operation, faults or firmware updates, you can reach our technical support in Germany, personally and without detours.

Planners & engineers

  • Unit certificates and declarations of conformity in the download centre

    Download the evidence you need for plant design, such as unit certificates to VDE-AR-N 4105 and 4110 or EN 50549, directly and without a request.

  • Complete technical data for comparison

    Every product page shows all values from the datasheet, from the MPPT voltage range to the overvoltage category, clearly arranged by group.

  • Direct contact with engineering

    For detailed questions on grid protection, reactive power or plant control, talk directly to our engineers, without detours.

Project developers

  • Grid-compliant operation to European grid codes

    REFUsol inverters are certified to EN 50549 and the German VDE application rules. This gives you planning certainty for the grid connection of your PV project.

  • Monitoring with data hosting in Germany

    With REFUview, you keep track of the output and availability of your plants. The data is hosted and processed in Germany.

  • Complete documents for permits and grid connection

    Unit certificates, declarations of conformity and datasheets are ready in the download centre, so the plant certificate and grid connection procedure move ahead quickly.

Utilities & grid operators

  • Power control via Modbus TCP/IP and DRM

    With REFUlink, you apply active and reactive power setpoints via Modbus TCP/IP or the DRM levels 0, 30, 60 and 100 % on all connected inverters.

  • Grid-compliant operation to grid codes

    The inverters meet the requirements of EN 50549 and the German VDE application rules for connection to low- and medium-voltage grids, certified and documented.

  • Data hosting in Germany

    Operating data is hosted and processed in Germany. This supports operators of critical infrastructure with data protection and information security.

Related solutions

Utility-scale solar projects

Inverters for large plants on medium-voltage grids.

Learn more

Grid integration

Grid codes, reactive power and power control for grid connection.

Learn more

Discuss your project

Questions about protection functions? We advise you personally, directly with our engineers.

Or directly+49 7121 145 1888info@refu.com

Request a project