The construction site of a solar photovoltaic system, like any other construction site, has many unsafe factors, including many electrically charged and non-electrical hazards. The vast majority of photovoltaic system engineering is in the outdoor, field or roof construction, when the installation of photovoltaic power generation systems and testing operations, be alert to potential physical, electrical and chemical hazards that may occur, such as sun exposure, insect and snake bites, impact, sprains, falls, burns, electrocution, burns, etc., listed below.
1. Common safety hazards
(1) Physical hazards
In the outdoor operation of photovoltaic power generation systems, usually by hand or power tools to operate electrical equipment, in some systems, but also the need for battery-related operations, the operation of a little carelessness, the operator may cause burns, electric shock and other physical hazards. Therefore, it is very important to use the tools correctly and safely and to take the necessary protective measures.
(2) Sunlight radiation
Photovoltaic power generation systems are installed in sunny places with no shadows, so when working under the hot sun for a long time, be sure to wear a sun hat and apply sunscreen to protect yourself from being burned by the hot sun. When the weather is hot, drink plenty of water and rest for a few minutes in the shade every hour of work.
(3) Insects, snakes and other animals
Hornets, spiders and other insects often inhabit junction boxes, the outer frames of PV arrays and other protective enclosures of PV systems, and snakes are often found in certain remote areas of the wild. Likewise, ants can also inhabit the PV array foundation or battery boxes. Therefore, precautions need to be taken when opening junction boxes or other equipment enclosures. Before going to work under or behind the PV array, you need to carefully observe the surrounding environment to avoid unexpected situations.
(4) Cut, impact and sprain
Many PV system components have sharp edges and corners, and injuries may occur if care is not taken. These parts include the aluminum alloy frame of the battery module, junction box shell flange, bolt and nut burrs, bracket edge burrs, etc.. Especially when drilling and sawing metal, make sure to wear protective gloves. In addition, when working under low PV arrays or system equipment, be sure to wear a helmet to prevent inadvertent head injury.
In handling batteries, battery components and other photovoltaic equipment, pay attention to the force evenly, or two people from handling, to prevent excessive force and sprain.
(5) Thermal burns
Under the summer sun, the temperature of the glass surface and aluminum alloy frame of the PV array will reach over 80°C. To ensure safety, prevent skin burns. To ensure safety and prevent skin burns, be sure to wear protective gloves when operating the PV system in summer and try to avoid hot parts.
(6) Electrical injuries
Electric shock can cause burns or shock to personnel, resulting in muscle contraction or trauma, or even death. If the current flowing through the body is greater than 0.02A, it will cause injury to the human body, the higher the voltage, the greater the current flowing through the body. Therefore, whether it is DC or AC, PV or grid electricity, as long as there is a certain voltage, it will cause injury. Although the output voltage of a single battery module is not much higher, but a dozen components in series output voltage is often higher than the inverter output AC voltage. When operating to avoid electric shock injury, one is to ensure that the relevant power supply is cut off; second, try to use a clamp-on ammeter for line current testing; third, wear insulated gloves.
(7) Chemical hazards
Off-grid photovoltaic power generation systems often use batteries as energy storage systems, lead-acid batteries are one of the common batteries. Lead-acid batteries use sulfuric acid as electrolyte, which is very corrosive and may leak during operation or produce spraying during charging. If it comes into contact with exposed areas of the body, the skin will be chemically burned. Also eyes are particularly vulnerable and clothes can be burned with a hole. Although electrolyte leakage from sealed lead-acid batteries is relatively rare, it is important to take precautions.
In addition, the battery will emit a small amount of hydrogen gas during the charging process, which is a flammable gas, and when the hydrogen gas accumulates to a certain concentration, it is very easy to explode or fire when it meets open flame or electric spark. Therefore, the place where the battery is placed should be well ventilated to avoid the accumulation of combustible gas and the injury caused by explosion or fire.
2. Safety protection
Construction site safety protection, not only to protect themselves, but also to protect the construction and operation of the surrounding partners, first of all, each to wear good protective equipment, but also in the work of mutual care, remind, collaboration, and each construction personnel should maintain a certain vigilance, do not be paralyzed. Things that require two people to operate together, or the need for two people to be present at work, do not act alone, do not save time and money to reduce the cost of employing people, safety is the biggest savings.
Commonly used safety protection supplies are helmets, protective glasses, gloves, shoes, safety belts, protective aprons, etc..
Safety helmet to protect the head from bruises or falling objects smashed.
Protective glasses have two roles, one is to protect the eyes from the stimulation of strong sunlight, the second is to carry out the installation and maintenance operations of the battery system, to prevent acid splashing into.
There are many kinds of gloves, different work content to choose different gloves. You can choose wire gloves for installation operation; canvas gloves for moving metal objects with sharp corners or burrs; rubber acid-resistant gloves for battery maintenance operation; high-voltage insulated gloves for electrical testing, etc. Of course, you can also choose high-quality full-function gloves for operation.
The choice of shoes depends on the workplace and environment. If the PV construction site is a new industrial environment, it is best to choose to wear hard-toe labor protection shoes; if it is a ground or mountain environment, it is best to choose standard work shoes or hiking shoes; if it is operating on the roof, it is best to choose rubber-soled work shoes.
Protective apron is required when operating on the battery.
Safety belts are required for working on roofs, ladders, etc.
