Compliance of inverters for photovoltaic installations is an important topic in France. The DIN VDE 0126-1-1/A1 standard, and more recently the European standard EN 50549, define the technical requirements to ensure the safety and performance of this equipment. Understanding these standards and knowing how to obtain the certificate of conformity is essential for any solar project, whether for self-consumption or grid injection.

Key Points to Remember

• The DIN VDE 0126-1-1/A1 standard, which governed inverter compliance, is being replaced by the European standard EN 50549, with an effective transition planned for 1st January 2025.
• Compliance with standards ensures the safety of solar installations, the protection of personnel working on the grid, and the energy efficiency of photovoltaic systems.
• Disconnection protection is a vital function integrated into inverters to disconnect the installation from the grid in the event of a power cut, thereby preventing electrical risks.
• Obtaining a certificate of conformity, often via Consuel, is a mandatory step for connecting solar installations to the electricity grid.
• Non-compliance of inverters can lead to safety risks, block grid connection, and compromise the overall performance of solar projects.

Understanding the DIN VDE 0126-1-1/A1 standard

The DIN VDE 0126-1-1/A1 standard is an important technical document for solar installations in France. It establishes the safety and performance rules that inverters must comply with. Initially, this standard was adopted to align with European standards, but it has evolved, notably with the VFR2019 version. These changes show how solar technology and electrical safety requirements are evolving. Compliance with this standard is therefore necessary for solar installations to be safe and function well with the electricity grid.

Definition and role of the DIN VDE 0126-1-1/A1 standard

The DIN VDE 0126-1-1/A1 standard defines the technical criteria for inverters in photovoltaic systems. It focuses on aspects such as disconnection and grid protection functions. These functions are there to ensure that the inverter disconnects from the grid in case of an issue, thereby protecting personnel and the grid itself. This is a key step for self-consumption and the sale of solar electricity. Compliance with this standard is therefore important for the smooth running of solar projects.

Evolution of the DIN VDE standard and its implications

The DIN VDE standard has undergone updates over time, such as the VFR2019 version. These evolutions are important because they reflect technological advancements and new safety requirements. For installers and owners, this means staying informed of the latest versions to ensure compliance. Germany, a pioneer in solar, has long used this standard, and many inverters on the European market were designed according to these standards. It is important to note that this standard is gradually being replaced by the European standard EN 50549.

Importance of compliance for solar installations

Compliance with the DIN VDE 0126-1-1/A1 standard is essential for several reasons. It guarantees the safety of people and property, ensures the proper functioning of the photovoltaic installation, and facilitates its connection to the electricity grid. Without this compliance, an installation may encounter administrative problems, such as blocking of the connection. Furthermore, it is often a condition for benefiting from purchase tariffs or support schemes. It is therefore recommended to ensure that the chosen inverter complies with the standard in force, or the standard that replaces it, as stipulated by UTE C 15-712-1.

Aspect of the standard	Description
Disconnection criteria	Conditions for automatic grid disconnection
Grid protection	Measures to prevent disturbances on the public grid
Installation safety	Ensuring equipment integrity and safety of personnel

Safety and performance requirements for inverters

For a photovoltaic installation to operate correctly and safely, inverters must meet strict criteria. These requirements aim to ensure the protection of the electricity grid and the people working on it, while optimising the energy efficiency of the system.

Tripping and disconnection criteria

The disconnection function is absolutely vital for any grid-connected installation. It ensures that the inverter stops injecting electricity if the public grid is cut off. This prevents any risk of electrocution for technicians working on the lines. Historically, the DIN VDE 0126-1-1 standard served as a reference for these devices, particularly in its VFR2019 version. Inverters for low-voltage installations generally incorporate this protection. It is important to ensure that the chosen inverter complies with these specifications for a secure grid connection.

Grid protection and installation safety

Beyond disconnection protection, inverters must incorporate protection mechanisms against grid overvoltages and undervoltages. They must also be able to maintain a stable connection even when the grid experiences frequency variations. These measures are intended to prevent damage to the inverter itself, but also to avoid disturbing the quality of electricity supplied by the grid. Compliance with standards such as NF C 15-100 is also required for the entire electrical installation, thereby ensuring overall safety. A well-protected installation is less prone to failures and ensures better equipment longevity. It is therefore essential to select inverters that comply with these protection standards for solar installations.

Energy efficiency and grid integration

The efficiency of an inverter is measured by its ability to convert the direct current produced by solar panels into alternating current usable by the grid. Current standards require high efficiencies, often exceeding 95%. Furthermore, inverters must be able to adapt to variations in solar production and grid demands. This includes reactive power management functions to help stabilise grid voltage. The objective is to maximise energy production while contributing to the stability of the electricity grid. The European standard EN 50549, which is gradually replacing DIN VDE, emphasises these aspects of integration and performance for generation equipment.

Compliance with safety and performance standards is not an option, but a necessity for the proper functioning and long-term viability of your photovoltaic installation. It guarantees the protection of all system elements and ensures harmonious integration with the public electricity grid.

Procedure for obtaining the certificate of conformity

For your solar installation to be recognised and connected to the grid, a key step is required: obtaining a certificate of conformity. This is somewhat like a building permit for your house, but for your photovoltaic system. Without this document, there’s no connection to the electricity grid, and therefore no usable or resaleable electricity production.

Selecting a compliant inverter

The first thing to do is to choose the right equipment. You need to ensure that the inverter you are going to install complies with the DIN VDE 0126-1-1/A1 standard. This is not just a matter of brand or price; it’s a guarantee that the equipment has been tested and will function correctly and safely with the grid. Remember to check the technical documentation provided by the manufacturer. It is strongly recommended to choose equipment listed on the C2P green list, which references validated technical opinions, a guarantee of quality and compliance. This greatly simplifies future administrative procedures, including grid connection.

Role of certified bodies and Consuel

Once your equipment is selected and the installation is complete, everything needs to be checked. In France, Consuel is primarily responsible for this. This independent body will inspect your installation to ensure that it complies with all current electrical standards, including those concerning the inverter. This is a mandatory step to connect your system to the grid. Other certified bodies may also intervene, but Consuel is the reference for most photovoltaic installations.

Inspection and validation of the installation

The inspection by Consuel (or a similar body) is quite detailed. They will check several technical points, such as protection against overvoltages, the proper functioning of the inverter’s disconnection (i.e., that it automatically disconnects in the event of a grid outage, for the safety of technicians), and the overall integration of your system. If everything is in order, Consuel then issues the famous certificate of conformity. This document is essential for finalising your connection application with Enedis. It certifies that your installation is safe and compliant with regulations, which is also important for your insurance and for the long-term viability of your solar project. For more details on standards, you can consult the UTE C15-712-1 guide.

Obtaining this certificate is a non-negotiable step to ensure the safety, compliance, and proper functioning of your photovoltaic installation.

Transition to the EN 50549 standard

The regulatory landscape for photovoltaic installations is evolving, marking an important shift from the German DIN VDE standard to the European EN 50549 standard. This transition, initially planned for June 2023, has been postponed to 1st January 2025, following discussions between industry stakeholders and Enedis. The objective is to harmonise connection requirements across Europe, thereby simplifying procedures and strengthening the safety and reliability of solar systems.

Replacement of the DIN VDE standard by the European standard

The DIN VDE 0126-1-1 standard, which has long served as a reference for inverter compliance in France, is gradually being replaced by the EN 50549 standard. The latter falls within the framework of the European network code ‘Requirements for Generators’ (RfG). It establishes precise technical requirements for electricity generation equipment to ensure their proper functioning and secure integration into the electricity grid. Network operators, such as Enedis, now rely on this standard to validate the compliance of installations.

New requirements for generation equipment

The EN 50549 standard, and more specifically EN 50549-1 for low voltage, defines the protection functions and operational capabilities that inverters must possess. This includes parameters such as acceptable voltage and frequency ranges, as well as the equipment’s response to grid variations. Annex C of this standard details these parameters, which can be specified by each network operator to adapt to the characteristics of its own network. Manufacturers must therefore ensure that their inverters are certified according to this new European standard, as evidenced by the certification of certain micro-inverters according to the EN 50549-10 standard.

Impact on the solar industry and installers

This regulatory evolution implies adaptation for the entire solar industry. Installers must now verify that the inverters they offer comply with the EN 50549 standard and obtain the corresponding certificates of conformity. Manufacturers, for their part, must ensure that their products meet these new European requirements. Certificates attesting to compliance with the EN 50549-1:2019 standard are essential for new installations. Until the deadline of 1st January 2025, certificates compliant with the old DIN VDE standards or the new EN 50549-1 standards will be accepted interchangeably. For compliance with the RIG code, a simple declaration on honour will be sufficient during this transitional period.

Enedis Clarifications on Compliance

Enedis, the electricity distribution network operator in France, has provided important clarifications regarding the compliance requirements for electricity generation equipment, particularly photovoltaic inverters. These clarifications aim to support the transition to new standards and ensure the safety and stability of the grid.

Modification of the Technical Reference Document

Enedis has announced a modification to its Technical Reference Document (TRD). Paragraph 4.2.1 of this document will be updated to reflect the new requirements. It is stipulated that after a 24-month transitional period following the adoption of the EN 50549-10 test standard, applicants will need to provide a certificate of conformity to the EN 50549-1 and EN 50549-2 standards. This update aims to harmonise practices and align with European standards, thereby facilitating the integration of renewable energies.

Transitional period and acceptance of standards

A transitional period has been put in place to allow professionals to adapt. Until 1st January 2025, Enedis will accept certificates of conformity to either the DIN VDE 0126 or EN 50549-1 standards interchangeably. This flexibility is a support measure for installers and manufacturers during this adaptation phase. It is important to note that for installations with a power output equal to or less than 36 kVA, the certificate of conformity to the NF EN50549 standard will be accepted even if it is not established according to the NF EN50549-10 test standard. This derogation is valid until 1st January 2026 for complete connection applications.

Declaration on honour for RIG code compliance

Regarding compliance with the RIG code (Requirements for Generators), Enedis has specified that for the time being, a simple declaration on honour will be sufficient. This temporarily eases administrative procedures for installers, while full certification procedures become fully operational and understood by all stakeholders in the sector. It is advisable to stay informed of future developments concerning this requirement.

It is therefore essential for installers to check with manufacturers the compliance of inverters with the new standards. This proactive approach is crucial for the success of solar projects and for compliance with current regulations, thereby contributing to the reliability of the national electricity grid. For more information on connection standards, you can consult ISGAN’s work on smart grid development.

Adapting to new standards is a continuous process. Enedis is committed to supporting professionals for a successful transition to more efficient and secure energy systems.

The role of disconnection protection

Disconnection protection, sometimes called an automatic disconnection device, is an absolutely necessary function for any installation that connects to the public grid. Its primary role is to stop the electricity production of your photovoltaic system if the public grid were to go down. This prevents your installation from continuing to inject current into a grid that no longer has any, which could be very dangerous for technicians working on the lines. This is a paramount safety measure.

For low-voltage (LV) connected installations, this protection is generally integrated directly into the inverter. This is quite practical. However, if your installation is high-voltage (HV), a separate piece of equipment is required, in addition to the inverter, to provide this disconnection function. This is then referred to as external disconnection protection.

Historically, many inverters sold in Europe were designed to comply with German standards, particularly DIN VDE 0126-1-1. This standard was replaced by VDE-AR-N 4105 in 2011, but Enedis’s technical reference document continued to rely on DIN VDE 0126-1-1/A1, including versions such as VFR2014 or VFR2019, until recently. It should be noted that since 1st January 2025, the European standard NF EN 50549 applies. It specifies the requirements for the protection functions and operational capabilities of electrical installations connecting to grids. For installations over 800 W for which the connection request is made after this date, a certificate of conformity to NF EN50549-1 (for LV) or -2 (for HV) will be required. This certificate must attest to the equipment’s compliance with the standard itself, as well as its test method (NF EN50549-10) and its Annex C.

Essential function for grid-connected installations

The automatic disconnection device serves as a safety interface between your solar system and the public grid. It is there to protect people and property in the event of a problem on the electricity grid. In low voltage, this protection must be able to detect several types of faults:

• Polyphase faults.
• Islanded operation (when the public grid is no longer present).
• Loss of upstream grid.

To do this, the system measures parameters such as frequency and voltage. These measurements are compared to limits defined by the network operator (DNO). If these limits are exceeded, the protection trips and disconnects the installation. It’s somewhat like a smart circuit breaker that ensures everyone’s safety.

Risk prevention for intervening personnel

The primary objective of disconnection protection is to ensure the safety of personnel working on the electricity grid. When a power cut occurs on the public grid, it is imperative that all connected generation installations, such as your photovoltaic system, immediately cease injecting electricity. If this were not the case, maintenance personnel could find themselves facing live cables without knowing it, creating a risk of serious, even fatal, electrocution. Disconnection protection acts as a silent guardian, ensuring that the solar system does not become an unintentional source of danger during grid interventions. This is a fundamental requirement for grid connection, and it is also specified in Enedis’s technical reference document, which details the information required for a grid connection request.

Integration into the inverter or external equipment

As mentioned, how this protection is integrated depends on the connection voltage. For low-voltage (LV) installations, the disconnection function is generally included in the inverter itself. This is a practical solution that simplifies installation. However, for high-voltage (HV) installations, stricter regulation applies. In this case, disconnection protection must be provided by a separate piece of equipment from the inverter. This means that an additional device is required to fulfil this critical safety function. The compliance of this equipment is often attested by certifications such as Qualipv 500, which guarantees that the installation complies with current standards.

Compliance with international and French standards

It is important to understand that electrical standards are not universal. Different countries, and even different regions, have their own sets of rules to ensure the safety and performance of installations, including those using photovoltaic inverters. In France, we rely on a specific normative framework that integrates international standards while meeting our own national requirements.

DIN VDE standards and their origin

DIN standards, and more specifically DIN VDE standards, originate from Germany. They are developed by the Deutsches Institut für Normung (DIN), the German Institute for Standardisation. This standardisation process is collaborative, involving manufacturers, industrialists, scientists, consumers, and authorities. Historically, the DIN VDE 0126-1-1 standard was a key reference for inverter compliance in many countries, including France, before the adoption of more recent European standards. These German standards served as a basis for ensuring the safety and interoperability of grid-connected equipment. It should be noted that inverters certified compliant with DIN VDE 0126-1-1 (VFR 2019) were accepted until 1st January 2025 [82c0].

French NF C standards and their application

In France, the electrical regulatory framework is largely defined by NF C standards, issued by the French Electrotechnical Committee (UTE). The best-known standard in the photovoltaic sector is NF C 15-100, which governs low-voltage electrical installations. This standard has been updated to integrate the specificities of solar installations, including requirements relating to inverters. NF C standards ensure that equipment and installations comply with French safety and quality standards. Compliance with these standards is often verified by bodies such as Consuel, which issues an essential certificate for grid connection [7d28].

IEC standards and their relevance

IEC (International Electrotechnical Commission) standards are international standards that aim to harmonise electrical and electronic standards on a global scale. They serve as a reference for many national standards, including DIN and NF C standards. For photovoltaic inverters, IEC standards define general requirements for safety, performance, and electromagnetic compatibility. Although national or regional standards such as the European standard EN 50549 are directly applicable for grid connection, they often rely on the principles established by the IEC. Understanding these international standards provides an overall vision of expectations in solar technology.

It is essential to ensure that the chosen inverter complies not only with German or European standards, but also with the specific requirements of the French network operator. The inverter is a central component of your solar installation, representing a significant part of the total cost, and its proper functioning is paramount for energy production [1a72].

Annex C of the Standard and Operating Parameters

Annex C of the standard details the specific parameters required for generation equipment to operate in parallel with the electricity grid. These parameters cover essential aspects such as acceptable voltage and frequency ranges, as well as the inverter’s response to grid frequency variations. It is important to note that each network operator may define its own values for these parameters, adapted to the characteristics of its network. For installations with a power output equal to or less than 36 kVA, exemption clauses are provided until 1st January 2026. During this period, a certificate of conformity to the NF EN50549 standard will be accepted even if it is not established according to the NF EN50549-10 test standard. Installers must ensure with manufacturers that their equipment complies with these requirements.

Key points of Annex C include:

• Operating voltage ranges: Voltage limits within which the inverter must remain connected and active.
• Operating frequency ranges: Grid frequency limits for which the inverter must maintain its connection.
• Response to grid events: How the inverter must react in case of under-frequency or over-frequency.
• Power parameters: Requirements related to active and reactive power management.

It should be noted that compliance with Annex C is a requirement for installations for which the connection request is made after 1st January 2025, for systems over 800 W. The certificate of conformity can be provided at the latest during commissioning, which does not block the completeness of the connection request. Network operators may specify parameters specific to their infrastructure, making the inverter’s technical documentation particularly important. For a compliant installation, it is necessary to consult the technical reference document of your network operator.

Consequences of Non-Compliance of Inverters

Installing a photovoltaic inverter that does not comply with current standards can lead to serious problems, both in terms of safety and regulatory compliance and connection. It is therefore imperative to understand the concrete repercussions linked to non-compliance with normative requirements.

Safety Risks and Electrical Malfunctions

Non-compliance of an inverter can cause:

• Grid protection faults in the event of an anomaly, which exposes to the risk of electric shock or fire;
• Endangering maintenance personnel during grid interventions;
• Repeated system failures or unpredictable behaviour of the inverter.

Ensuring inverter compliance limits risks to people and property and avoids premature shutdowns of solar production.

Certain control points, such as disconnection protection, are mandatory to guarantee the safety of the entire installation, as specified in the requirement of the VDE 0126-1-1 standard.

Blocking of Electricity Grid Connection

Connection to the public grid cannot take place if the inverter has not received an official certificate of conformity. The absence of this document blocks:

• The signing of the injection or self-consumption contract with the network operator (e.g., Enedis)
• The final project validation by Consuel
• Any legal commissioning of the installation

A summary table of the consequences:

Non-compliance observed	Immediate effect
Missing certification	Refusal of connection
Proven safety defects	Prohibition of operation
Consuel inspection not validated	Commissioning blocked

These blockages imply delays and additional costs for the regularisation of the situation.

Compromise on the Efficiency of Solar Projects

A non-compliant system does not guarantee the expected performance. This results in:

• Reduced or fluctuating energy production;
• Unforeseen interruptions, impacting the overall profitability of the project;
• Limited, or even impossible, access to public aid and subsidies.

In summary, inverter compliance is not just an administrative formality: it is a pillar of the long-term success and efficiency of any solar installation. To ensure compliance with requirements, it is advisable to check compliance upstream and obtain the adequate certificate, essential particularly during the final declaration to Consuel.

When your inverters do not function correctly, this can cause problems. Imagine your solar system not producing the expected electricity, or worse, breaking down. This can lead to financial losses and technical issues. It is therefore crucial to ensure everything is in order. To learn more about how to avoid these inconveniences and guarantee the proper functioning of your installation, visit our website today!

In summary: what to remember for the compliance of your installation

So, we’ve covered the topic of standards for photovoltaic inverters. It’s true that it might seem a bit technical at first, with all these standards like DIN VDE 0126-1-1 and now the new EN 50549. The important thing is to know that all of this exists to ensure your solar installation works well and, above all, safely. Whether you are setting up your project or already have panels, you need to keep an eye on these developments. The good news is that many installers and manufacturers are already up to date with these new rules, such as the EN 50549 standard which is coming soon. Don’t hesitate to ask for certificates of conformity, that’s your guarantee. Ultimately, it’s a necessary step for reliable and sustainable solar energy.

Frequently Asked Questions

What is the purpose of the DIN VDE 0126-1-1/A1 standard for inverters?

This standard is somewhat like a safety regulation for devices that convert the current from your solar panels. It dictates how the inverter must behave to ensure everything is safe, especially when it’s connected to the electricity grid. It checks that it disconnects properly if the grid has an issue, to prevent accidents.

Why is it important for my inverter to comply with this standard?

It’s very important for several reasons! Firstly, it ensures that your solar installation is safe for you and for the technicians working on the grid. Secondly, it ensures that your inverter functions well and is compatible with the electricity grid. Without this compliance, your installation might not be accepted or might not function correctly.

Where can I find the certificate of conformity for my inverter?

To get this proof that your inverter is compliant, you generally need to go through official bodies like Consuel in France. They check that everything is properly installed and complies with the rules. The manufacturer of your inverter can also provide you with a certificate of conformity.

What is Consuel and what is its role?

Consuel is somewhat like the electrical safety body in France. When you install a solar system, they come to check that everything is properly done and that it complies with safety standards. If they approve, they give you a document, the certificate of conformity, which states that your installation complies with standards.

What happens if my inverter is not compliant?

If your inverter is not compliant, it’s problematic. It can create safety problems, such as short circuits. The biggest concern is that the electricity network operator, like Enedis, might refuse to connect your installation. Consequently, your solar project might not function as planned.

Will the DIN VDE 0126 standard be replaced? By what?

Yes, it is! The DIN VDE 0126 standard is being replaced by a new European standard, EN 50549. This is partly to harmonise the rules across Europe. Installations must now comply with this new standard, but there are transitional periods.

What is disconnection protection and why is it important?

Disconnection protection is a very important safety function. Basically, it ensures your inverter stops producing electricity if the electricity grid goes down. This prevents the inverter from sending current where it shouldn’t, which could be dangerous for people repairing the grid.

What is Annex C of the standard and what is its purpose?

Annex C is a list of settings that the inverter must comply with to function properly with the grid. For example, it specifies the voltage or frequency limits within which the inverter must operate. These settings are important for the inverter and the grid to communicate well together and for everything to run smoothly.