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Brazils National Institute of Metrology, Quality and Technology (Inmetro) says it has introduced a requirement for inverters to have arc-fault circuit breakers, starting in December 2024, to prevent fires and improve PV system safety.
Solar inverters in Brazil must include arc fault circuit interrupters (AFCI) starting December 1, according to new Inmetro rules.
According to sources who informed pv magazine , several distributors have started selling non-compliant inverters at low prices. This creates unfair competition with companies that have already updated their products and could lead to losses for customers who are unaware of mandatory protective devices and upcoming fire inspections after the deadline.
Leandro Michels, coordinator of the photovoltaic inverter testing laboratory of the Intelligent Grids Institute (INRI) of the Federal University of Santa María (UFSM), said that manufacturers should not rely solely on Inmetro requirements.
“The Inmetro ordinance sets a period for non-AFCI products to continue to be marketed, but this does not mean that the Fire Department will accept new buildings without protection,” he said. “Evaluating the product is one thing, implementing it is another, and the fire department has the prerogative to decide whether a product can be used or not, from an electrical safety point of view. Therefore, they can create stricter rules, even for products that can be sold.”
Northern Electric and Power (NEP) has prepared for the new regulations. NEP sales director Marcus Serrano explained that unlike other major distributors in the market, the company did not have to sell the stock of inverters without the AFCI device.
"At the beginning of next year these devices will not even be available for sale, and the installers who bought them for stock will have a lot of work to do to adapt, unfortunately," said Serrano.
The standard requiring the inclusion of AFCI in photovoltaic systems has moved from regionalization to national standardization. Initially, several states, including Mato Grosso, Minas Gerais and Goiás, implemented their own regulations focused on fire safety, particularly in commercial and industrial buildings.
The Brazilian National Council of Military Firefighters (Ligabom) played a key role in unifying these regional initiatives. In 2022, discussions began to make this protection mandatory nationwide, leading Inmetro to adopt the technical standard through Ordinance 140/2022 to improve safety in photovoltaic installations across the country.
Consequences of non-compliance
Failure to comply with the new rules can have serious consequences. For facilities that require fire department permits, such as large plants, businesses, and industries, the absence of AFCI can result in failed inspections, preventing the renewal of licenses such as the Fire Department Inspection Report (AVCB) or Certificate of Conformity (CERCON).
Consumers who purchase equipment without AFCI protection may incur additional costs for future modifications if their systems require adjustments during inspections.
The results of the AFCI inverter certification tests indicate that there is still much work to be done. According to INRI technical consultant Ricardo JF Bortolini, a laboratory in Brazil found that only 18% of the products passed the initial test, while 64% did so after adjustments. Bortolini stressed the importance of equipment certification, laboratory accreditation by Inmetro and the need for local inspections.
Elgin Solar director Glauco Santos highlighted the growing demand for equipment that complies with the new standard.
“Our network of installers is always attentive to changes and market demands. As a result, we have noticed a significant increase in demand for inverters with AFCI protection mechanisms,” he said. “Our R&D department has already been working on adapting our inverters to meet the requirements of Inmetro and the fire department.”
Levi Santos Cidral Junior, GD solar engineering coordinator at Brazilian inverter manufacturer WEG, said the company had anticipated this market need.
“We have had options for photovoltaic inverter lines with AFCI included as standard for some years now, as we know that even though it is not mandatory, it is still very important to provide access to the technology,” he said. “This old inclusion was already part of a movement to include it in the entire line. The obligation by Inmetro is finally coming and we now have 100% of inverters with AFCI.”
Harry Neto, director of Solar and Buildings at WEG, said safety concerns should be a priority for manufacturers, as they already are in other sectors.
“Even our smallest microinverters were tested under the ordinance to ensure that no arcing occurs,” he said. “Buying equipment that does not meet the standard will be the equivalent of buying a car without a seatbelt.”
Equipment risks
Beyond bureaucratic and financial issues, AFCI plays a critical role in detecting and interrupting arc flashes, which are one of the leading causes of fires in PV installations. As Brazil experiences exponential growth in solar energy adoption, incidents of fires involving PV systems have also increased, highlighting the need for more robust protection mechanisms. AFCI can detect an arc flash in the system and interrupt it before it develops into a more dangerous situation, such as a fire.
“In a traditional system, if maintenance is required, the inverter is turned off. However, the voltage level between the inverter and the modules remains high and it is not possible to turn it off,” says Juliano Pereira, country manager for Brazil at Israel-based inverter manufacturer SolarEdge. “This voltage level creates a risky environment for people. In the event of a fire, the level is so dangerous that even the Fire Department has difficulty responding. In the case of the SolarEdge solution, we always offer a safe voltage level. So even if there is a change in legislation, our system is prepared for it.”
To solve this problem, the manufacturer offers its energy optimization technology, which allows modules to operate independently. This technology ensures higher generation and better visibility for asset management, thus reducing losses and costs.
Quick shutdown?
Another relevant standard is rapid shutdown (RSD), which many Brazilian states are considering as an additional safety solution.
One problem with photovoltaic systems is that they generate electrical voltage as long as light shines on the panels, even if the inverter or the power grid is switched off. This poses risks for maintenance and firefighting.
RSD can reduce the electrical voltage generated by panels in emergency situations, effectively “shutting down” the panels and decreasing the risk of electric shock for firefighters and rescue teams. Currently, RSD is not mandatory nationwide and its implementation depends on regional regulations. States such as Goiás already require RSD in commercial and industrial systems to obtain AVCB/CERCON, while others are evaluating its adoption.
Ligabom has not yet commented on the standardisation of rapid shutdown throughout the country. “Safety systems are complementary to each other. In other words, both AFCI and rapid shutdown are necessary to issue AVCB in companies, industries and large plants,” said Captain da Costa.
Compliance with these standards is a necessary step for the Brazilian photovoltaic market, ensuring the safety of installations and protecting all those involved in the operation and maintenance of solar systems.
Recommendations for consumers
Isabelle Sene, technical and regulatory specialist at the Brazilian Association of Photovoltaic Solar Energy (Absolar), said that consumers should look for reliable companies with a good reputation and that meet safety and quality standards.
These companies must be accredited by the Regional Council of Engineering and Agronomy (Crea) and, if possible, associated and certified by the entity. The equipment must display the Inmetro seal and include information about the safety devices in the data sheet.
“Under no circumstances should consumers modify the electrical installation or the configuration of the equipment themselves. All procedures must be carried out by specialised technicians, preferably authorised by the companies supplying the equipment,” says Sene. “Consumers who need to make modifications to their project can check in advance whether their equipment already has such devices and look for companies qualified to make modifications and adaptations to the project, bearing in mind that adaptations are essential for life safety.” |
