Hotovoltaic Solar Fire Protection Quick Switch Protection Rapid Shutdown

With the implementation of the county-wide promotion process, photovoltaic power stations increased significantly. Due to the complexity of the installation environment, the risk of fire is high. More than 80% of power stations catch fire because of faults on the DC side. If the DC high voltage cannot be turned off, there will be hidden dangers of electric shock on the spot.

Therefore, before the fire response, the power station operation and maintenance personnel need to shut off the photovoltaic system and cut off the power supply to ensure the safety of firefighters and the stability of the power grid. The quick Turn-off (RSD) function was created.

01 What is Rapid Shutdown (RSD)?

Rapid Shutdown (RSD) is the concept of photovoltaic power station safety protection proposed by the National Electrical Code (NEC) of the United States.

In some countries, including Australia, Germany and the United States, with the increase in photovoltaic systems, more and more firefighters are requiring the installation of "fire switches" to reduce the risk of electric shock when operating in photovoltaic systems.

As early as 2014, the United States published the NEC2014 690.12 "component-level self-shutdown solutions" standard, which requires rapid shutdown of photovoltaic systems.

Photovoltaic systems must be capable of quick shut-off in accordance with the NEC690.12-2017 regulation. With the distance to the photovoltaic matrix 305mm as the limit, within 30 seconds after the quick turn-off device starts, the voltage outside the limit range is reduced to below 30V, and the voltage within the limit range is reduced to below 80V, which requires the realization of "component-level turn-off".

02

Why is rapid Turn-off (RSD) important?

Due to the photovoltaic system is electrically charged equipment, power voltage is higher, and the equipment and circuit current always exist, the photovoltaic system in the fire accident in the past, even shut down the grid power supply, and the inverter automatically closed, from components to the inverter wire still charged or controller, dc high voltage to the personal safety is a huge hidden trouble.

In case of emergency, the quick shutdown (RSD) function reduces the component voltage to the safe voltage, realizing the quick shutdown of the component level, providing higher personal safety protection for the owner, installation operation and maintenance personnel, and firefighters.