In 2025, YRO, a Chinese photovoltaic enterprise, announced that its self developed module level rapid shutdown device has passed the UL 3741 certification. This breakthrough not only indicates that YRO has joined the international first tier safety technology camp but also elevates its product competitiveness from a “cost advantage” to a new height of “safety innovation”.
What exactly is the UL 3741 certification? This article will delve into what the UL 3741 certification is and why it is crucial for solar products.
What is the UL 3741 Certification?
1. Definition and Core Requirements
UL 3741 is a special certification standard for the rapid shutdown of photovoltaic modules formulated by Underwriters Laboratories (UL), an internationally authoritative safety organization. Its core objective is to reduce the voltage within 1 meter of the photovoltaic module to below 30V within 30 seconds, after the system triggers the shutdown command, thus eliminating the fatal threat of high voltage direct current to personnel (especially firefighters).
This certification encompasses three major technical thresholds:
Module level independent shutdown: Each photovoltaic module must be integrated with an independent control unit, rather than relying on an inverter or a centralized shutdown device.
Multiple triggering mechanisms: It supports dual triggering modes of automatic (such as temperature sensors, arc detection) and manual (remote switch, physical button).
Fail safe design: In case of communication interruption, power failure, or equipment failure, the system must automatically enter the shutdown state.
2. The Essential Difference from UL 1741
UL 1741 is a general safety standard for photovoltaic inverters, focusing on grid connected electrical performance (such as over voltage protection, islanding effect). In contrast, UL 3741 is the first “scenario based safety standard” for rapid shutdown at the module end, and the two complement each other. A product that has passed the UL 3741 certification, means that its safety design has covered all risk points in the entire link from the module to the grid.
Why is the UL 3741 Certification Crucial for Solar Products?
1. Addressing Safety Challenges Brought by the Popularization of Solar Energy Systems
With the popularization of the solar energy industry, more and more residential and commercial buildings choose to install solar photovoltaic systems. Although solar energy brings clean and renewable energy, a series of safety issues need to be addressed during installation and maintenance. Especially when solar energy systems are installed in high rise buildings or remote areas, in case of a fire, traditional electrical equipment may not be able to cut off the power in time, posing serious safety hazards.
As an effective means to solve this problem, the RSD can quickly cut off the current in case of emergencies such as fires. The UL 3741 certification ensures that these devices can operate reliably under extreme conditions, thus guaranteeing the safety and reliability of the system. This is of great significance for the popularization and promotion of solar energy systems, as it can alleviate the safety concerns of consumers and installers and boost market development.
2. Providing Better Protection for Firefighters
In the event of a fire, the safety of firefighters is of utmost importance. Uncertified solar energy systems may still be energized, increasing the risk of electric shock during fire fighting. However, the rapid shutdown device with UL 3741 certification can quickly cut off the power supply, ensuring that there is no continuous current flow at the fire site, thus providing better protection for firefighters.
3. Complying with Global Safety Standards and Enhancing Product Credibility
3. Complying with Global Safety Standards and Enhancing Product CredibilityThe UL 3741 certification is a globally recognized safety standard, and many countries and regions require solar products to meet this certification requirement. Especially in the United States, the UL 3741 certification is crucial for the installation and operation of solar photovoltaic systems. If a module level rapid shutdown device does not obtain the UL 3741 certification, it may not meet the safety regulatory requirements of some regions, thus affecting the market access of the product.
Conclusion
YRO’s acquisition of the UL 3741 certification, is not only a technological breakthrough, but also marks the strategic upgrade of YRO’s photovoltaic industry from “manufacturing export” to “standard export”. As the global energy transition enters a deep water zone, safety will become a more important core competitiveness than efficiency.