Many households pay little attention to PV plants after they have been installed. In most cases, when PV systems are operating properly, they can provide us with a constant supply of electric energy without human intervention. But this is, after all, a set of power production equipment, containing numerous materials, if not pay attention to the daily maintenance, may make the power plant power generation reduced, or even cause fire and other dangers. Therefore, the daily maintenance of photovoltaic power plants should not be ignored, especially the following 6 things.

Cleaning of contaminants
The general life of PV modules is about 25 years. Regularly cleaning the module panels of bird droppings, leaves and other shading materials can ensure that the PV panels maximize exposure to sunlight. If you usually love cleanliness and have high requirements for power generation effect, you can also clean the modules by yourself, but you need to pay attention to the following points.
1. Generally choose to clean the modules in the morning or late afternoon. Do not stand less than 1 meter from the edge of the roof when cleaning.
2. Before cleaning the modules, you should check whether there is any abnormal power output in the monitoring records, analyze whether it may cause leakage, and check whether the connecting wires and related components of the modules are damaged or stuck.
3. Personnel cleaning components should wear appropriate work clothes and a hat to avoid scraping and injury. Hooks, straps, threads and other parts that can easily cause traction should be prohibited on clothes or tools.
4. It is strictly forbidden to clean PV modules under the weather conditions of high wind, heavy rain, thunderstorm or heavy snow. Winter cleaning should avoid flushing, and do not flush with cold water when the panel is very hot.
5. It is strictly forbidden to use hard and sharp tools or corrosive solvents and alkaline organic solvents to wipe the PV module, and forbid to spray the cleaning water to the module junction box, cable bridge, sink box and other equipment.

Maintenance of modules and brackets
1. PV module surface should be kept clean, should use dry or damp soft clean cloth to wipe the PV module, strictly forbid the use of corrosive solvents or hard objects to wipe the PV module. Should be in the irradiance lower than 200W/m2 clean photovoltaic modules, should not use and components with a large temperature difference of liquid cleaning components.
2. The charged warning mark on the PV module should not be lost.
3. PV modules should be inspected regularly, and PV modules should be adjusted or replaced immediately if the following problems are found.
-- PV modules with crushed glass, scorched backsheet, obvious color changes.
-- PV modules with the presence of bubbles forming a connecting channel between the edge of the module or any circuit.
-- PV module junction box is deformed, twisted, cracked or burnt, and the terminals cannot make good contact.
4. Using metal frame photovoltaic module, the frame and the bracket should be well combined, the contact resistance between them is not more than 4Ω, the frame must be firmly grounded.
5. Use DC clamp-on ammeter to measure the input current of each PV module string connected to the same DC current sink under the condition that the solar radiation intensity is basically the same, and the deviation should not exceed 5%.
