We need to know fire protection measures of photovoltaic power plants
With the photovoltaic power station, especially the rooftop distributed photovoltaic power generation has been widely popularized. While photovoltaic power generation benefits the people, there are often reports of fire accidents or even accidental personal injury and major property losses due to photovoltaic power plants. Today, let’s discuss the fire safety issues that should be paid attention to during the operation and maintenance of photovoltaic power plants.
The DC side of photovoltaic power generation has high voltage and large current. There are many string connectors, and the installation environment is complicated. Many connectors are exposed to sunlight or exposed to wind and rain, which are prone to poor contact and even fire, burning and other fire hazards. Electrical fires are very dangerous, and once they happen, the losses will be heavy. Therefore, the principle of “prevention first” must be implemented to prevent electrical fires before they occur.
Photovoltaic power plants mainly prevent circuit fires, including:
· The DC side connector sparks the arc and causes a fire;
· Equipment failure causes fire (combiner box, inverter, distribution box, transformer, high and low voltage switchgear, etc.);
· Lightning strikes cause fires, etc.
If a fire is found in the power facilities of the photovoltaic power station, the inverter should be turned off immediately, the AC power supply should be cut off, and then the circuit of the photovoltaic string should be disconnected as soon as possible to completely cut off the arc source of the photovoltaic string, so as to ensure the safety of firefighting personnel and control the fire in the later stage. .
In a critical situation, in order to gain the initiative to put out the fire and gain time to control the fire, you can put out the fire with electricity on the condition of ensuring personal safety, and then cut off the power supply at the appropriate time, but you must pay attention to safety.
In the event of a fire in a photovoltaic power station, the firefighters should be informed and reminded of the electrification of the rooftop photovoltaic equipment as soon as possible. The firefighters had better wear insulating shoes. Do not touch the body or the fire extinguisher in your hands with live wires or electrical equipment to prevent electric shocks during firefighting.
The photovoltaic power station should be equipped with sufficient fire-fighting equipment, including dry powder fire extinguishers, carbon dioxide, 1211, carbon tetrachloride fire extinguishers or dry sand. Water and foam fire extinguishers are strictly prohibited for electrical fires.
For inverters, controllers and other precision instrument circuits or electrical equipment such as motors that track brackets, it is generally not suitable to use dry powder, sand, etc. to extinguish fire. Carbon dioxide, 1211, and carbon tetrachloride fire extinguishers should be used to extinguish the fire. In order to prevent debris from falling into the equipment cause greater losses.
At the same time, it is also necessary to maintain a certain distance when using equipment to extinguish fire: (1) The minimum distance between the nozzle and the charged body should not be less than 0.4 m for the voltage of 10 kV and below, and should not be less than 0.6 m for the voltage of 35 kV and above; (2) ) When a ground fault occurs in the high-voltage electrical equipment or line of the photovoltaic power station, the indoor rescue personnel shall not enter within 4 m from the fault point; the outdoor rescue personnel shall not approach within 8 m from the fault point, and must wear insulating shoes (withstanding voltage level) when entering the above range 10KV or more), wear insulating gloves when touching the equipment shell and frame.