Waterproof junction box
The figure below shows the waterproof junction box. Its structure is compared with the splash-proof junction box. The structure of the other parts is the same except that the cover 2 and the junction box body 1 are connected differently.
The structural feature of the waterproof junction box is that the cover 2 of the junction box and the junction box body 1 are connected by threads. Relying on the tightening force of the cover and the junction box body, the sealing ring made of heat-resistant black rubber is evenly pressed on the entire circumference, so that even if there is serious water vapor or harmful gas, it will be sealed well. Block it so as not to penetrate into the junction box.
The waterproof performance of the waterproof junction box should withstand a distance of 5 meters. Use a faucet with a nozzle diameter of about 25 mm to spray water in any direction. The water pressure before the nozzle outlet is not less than 2 kg/cm. The test lasts for 5 minutes. Open the junction box after the test Observe the cover, and no water should penetrate into the junction box.
The thermocouple and thermal resistance of the junction box with waterproof performance are suitable for the scene where water is often sprayed. For example, the equipment installed in moldy weather or indoor equipment needs to be cleaned frequently. In addition, the waterproof junction box is easy to assemble and disassemble. After the cover of the junction box is opened, it is bolted to the junction box body with a chain, so it will not be lost. These are more suitable for high-altitude equipment. [1] 
Waterproof junction box
Generally, the junction box is composed of a box cover, a box body, a terminal, a diode, a connecting wire, and a connector.
The use requirements are as follows:
1) The shell must have strong anti-aging and ultraviolet resistance;
2) Meet the requirements for use under harsh outdoor environmental conditions;
3) The self-locking function makes the connection method more convenient and firm;
4) There must be a waterproof seal design, scientific insulation protection against electric shock, and better safety performance;
5) The wiring terminals should be installed firmly and have good weldability with the bus;
6) The main function of the diode is the one-way conduction function;
7) Connectors and connecting wires: with good insulation performance, male and female plugs with self-locking function make the solar panel and electrical connection more convenient and reliable.