According to reports, the daily operation and maintenance of photovoltaic power plants mainly include:
1. Regularly check whether the connection between the photovoltaic modules is firm; 2. Whether the link in the square array junction box is firm;
3. Check whether the photovoltaic modules are damaged or abnormal; 4. Check whether the connection between the square array supports firm; 5. Whether the relationship between the support and the grounding system is reliable;
6. Whether the connection between the cable metal sheath and the grounding system is reliable, etc.;
Chapter 1: Daily maintenance of photovoltaic power plants
According to reports, photovoltaic power plants' daily operation and maintenance mainly include 1. Regularly check whether the connection between the photovoltaic modules is firm; 2. Whether the connection in the square array junction box is firm; 3. Check whether the photovoltaic modules are damaged or abnormal; 4. Check whether the connection between the phalanx supports is firm; 5. Whether the connection between the support and the grounding system is reliable;
6. Whether the connection between the cable metal sheath and the grounding system is reliable, etc.;
1. Maintenance of photovoltaic modules
Usually, a hot spot detection is carried out once a month, and a bracket test is carried out once every two months (depending on the situation of the power station). Investigate immediately to find the cause and fix it. As we all know, photovoltaic power generation needs to rely on sunlight to generate electricity. Therefore, the efficiency of power generation depends largely on the cleanliness of the panels. If there is too much dust and dirt on the surface of photovoltaic modules, the average photovoltaic power generation efficiency will drop by 15% or more. Therefore, it is necessary to clean the photovoltaic modules regularly. "As for the frequency of cleaning, it depends on the situation of the power station. Once the power generation drops by about 5%, it should be cleaned immediately."
Note: The best cleaning time is morning and evening;
2. Maintenance of the inverter
As a bridge of the photovoltaic system, the cost of the inverter in the entire system has been minimal, but its role cannot be ignored. Therefore, the maintenance of the inverter has also become an essential part of the operation and maintenance of the photovoltaic power station.
1. Regularly clean the dust on the inverter box; 2. Regularly clean the dirt in the inverter vent;
PV Power Plant Maintenance Manual
1.The use and maintenance of solar cell array
(1) The solar cell array should be installed where there are no high buildings, trees, poles, etc., to block the sunlight to obtain sunlight fully. My country is located in the northern hemisphere, the lighting surface of the square array should be placed in the south, and the inclination angle can be appropriately increased by 5°-15° compared with the local latitude. The installed angle between the Shanghai area is 38OC.
(2) During the transportation, installation, and use of the solar cell array, the components should be handled with care, and collision, knocking, and scratching are strictly prohibited not to damage the encapsulating glass, affecting the performance, and shorten the lifespan.
(3) The lighting surface of the solar cell array should always be kept clean. If there is dust or other dirt, it should be rinsed with water first and then wiped off the water with sterile gauze. Do not rinse with complex objects or corrosive solvents. , wipe.
(4) Pay attention to the positive and negative polarities of the output connection of the solar cell array, and do not reverse it. (6) The solar cell phalanx, whose angle can be adjusted manually, should adjust the sunward inclination and azimuth angle of the phalanx bracket according to the changes of seasons to make full use of the solar energy, except when it must be fixed.
(7) The photoelectric parameters of the solar cell array should be detected irregularly by the appropriate methods during use. If problems are found, they should be solved in time to ensure an uninterrupted power supply of the phalanx.
(8) Guardrails or walls should be added around the solar cell array and its supporting equipment to avoid an animal or human damage. In areas with heavy lightning or high mountains, grounding, lightning arresters, and lightning rods should be installed to prevent lightning strikes.
2.Control inverter usage precautions and maintenance
1) During installation, operation, and routine maintenance, do not directly contact high voltage positive and negative electrodes. At the same time, care should be taken not to leave tools and other sundries in the control cabinet to avoid short-circuit failure.
2) The working environment of the equipment should be dry, ventilated, and moisture-proof.
3) The cabinet should be kept clean. If it is found that there is a lot of dust, it should be cleaned in time after the power is turned off to avoid excessive dust and reduce the insulation strength.
4) Pay attention to various status displays in the computer and regularly report the inverter data to relevant experts and professional technicians for analysis to ensure timely detection and prevention of accidents.
5) During transportation, first remove all wiring, and it is strictly forbidden to collide, and do not turn it upside down. Next, the machine should be placed in a well-ventilated place, with the back and sides at least 10 cm away from the wall, so that the incoming and outgoing air can be kept unobstructed. Avoid placing in direct sunlight. It should be kept away from fire sources and high temperatures to prevent the temperature from being too high, and the indoor temperature should not exceed 40 ℃. Finally, avoid placing in a corrosive gas environment.
6) Pay attention to various status displays in the computer and regularly report the inverter data to relevant experts and professional technicians for analysis to ensure timely detection and prevention of accidents.
7) Maintenance and overhaul
a. Regularly check whether the wiring of each part of the inverter is firm, whether there is a looseness and overheating, and especially carefully check the grounding of fans, power modules, input terminals, and output terminals.
b. If there is an alarm and stop, it is not allowed to start the machine immediately. The reason should be found out and repaired before starting the engine. The inspection should be carried out according to the steps specified in the inverter maintenance manual.
c. Operators must be specially trained to be able to judge the causes of general faults promptly and eliminate them, such as being able to replace fuses, components, and damaged circuit boards skillfully. Therefore, untrained personnel is not allowed to operate the equipment.
d. If there is an accident that cannot be easily eliminated or the cause of the accident is unknown, detailed records of the accident shall be made, and the data recorded in the computer shall be backed up in time and submitted to the contractor together to solve the problem as quickly as possible.
Maintenance staff training
Training work is vital to ensure the daily maintenance of the power station, and the training objects are mainly the personnel arranged by the local power management system. Therefore, there are mainly two parts: basic knowledge training and practical operation training.
The main content of the basic knowledge training is the knowledge of solar energy systems, macro aspects such as engineering design, installation and debugging, etc., to guide the relevant personnel of the power station to have a systematic and comprehensive understanding of the power station. In addition, practical operation training is held on-site. Through on-site training and practical operation guidance, operators can better grasp relevant capabilities.
To enable the trainees designated by the developer to master the training knowledge and skills from the combination of theory and practice, the trainees should participate in the installation and commissioning of the project and obey the unified command and dispatch of the project headquarters during the construction process.
To deepen the training effect, the technical supervisors arranged by the contractor should have at least a college degree or above, graduated from mechanical and electrical majors, or other professionals with practical experience in solar system installation. During the actual installation and commissioning process, knowledge lectures can be held for local personnel.
The company is willing to provide extensive and timely technical support for system users during the construction period, including technical consultation and voluntary training.
After the completion and acceptance of the project, the contractor will continue to provide after-sales training services for the power station, whether within the warranty period or outside the warranty period.
After-sales service content
1. Obligation to provide technical advice
2. Supply spare parts and guarantee the delivery within 48 hours after confirmation;
3. During the system's warranty period, the faulty parts will be replaced free of charge, and the accessories fee not exceeding the transaction price of this contract will be charged outside the warranty period. Technical support and maintenance service guarantee
The contractor's commitment to the power station system warranty period: 3 years for the system, five years for the solar cell module, and three years for the controller.
During the warranty period, the warranty content of the power generation system:
Due to improper design, installation, and guidance. The performance parameters of the equipment or spare parts provided by the power supply cannot meet the design index requirements; the system or equipment fails due to lightning.
During the warranty period, the warranty contents of essential equipment: a. Warranty contents of solar cell modules: the power output drops significantly; there is a short circuit or open circuit in a single module;
The glass bursts naturally (except those exceeding the environmental index), and the junction box falls off. b. Warranty content of the controller: the output voltage exceeds the stable range; the output power fails to meet the index requirements; failure to effectively ground causes an accident;
For any faults within the scope of the warranty, the contractor will send personnel to solve and replace equipment and spare parts on-site free of charge.
Any losses caused by human error, natural disasters, artificial damage, or failure to effectively implement the protective measures proposed by the contractor are not covered by the warranty. However, the company promises that as long as the fault is reported for repair, it will send someone to repair it and charge appropriate fees. In addition, the cost of accessories and equipment will not exceed the transaction price of this contract.
Operation and Maintenance
1. What are the common faults of distributed photovoltaic power generation systems? What are the typical problems that may occur in various system components?
The inverter cannot work and cannot be started because the voltage does not reach the startup setting value, and the power generation is low due to the components or the inverter. Typical problems in the system components include the burning of the junction box and the partial burning of the details.
2. What is the PID phenomenon? In what environment will the distributed photovoltaic power generation system occur? How to diagnose and avoid the impact?
PID (Potential Induced Degradation), also known as "potential induced degradation," refers to the power degradation of photovoltaic modules induced by external factors. According to the mechanism of PID phenomenon, module manufacturers have developed a series of production processes to prevent the occurrence of PID phenomenon, including using anti-PID cells, increasing the volume resistivity of module composite materials, reducing the water vapor transmission rate of materials, photovoltaic systems Negative grounding, double-glass frameless components, etc., verified by tests and actual system operation data, even if the photovoltaic power generation system is built in a high temperature and high humidity environment, the generation of PID can be well avoided.
3. How long is the lifespan of a distributed photovoltaic power generation system?
The core components of photovoltaic modules have a life span of more than 25 years, and photovoltaic inverters are generally more than five years old. For details, please refer to the warranty policy. 4. What main factors lead to the decline and loss of photovoltaic power generation system efficiency?
The efficiency of the photovoltaic power generation system is lost due to external influences, including shading, gray layer, component attenuation, temperature influence, component matching, MPPT accuracy, inverter efficiency, transformer efficiency, DC and AC line losses, etc.
The influence of each factor on efficiency is also different. Therefore, in the early stage of the project, attention should be paid to the optimal design of the system, and specific measures should be taken during the operation of the project to reduce the impact of dust and other obstructions on the system.
5. In the case of specific roof resources, how to increase the power generation of the distributed photovoltaic power generation system?
The power generation of the distributed photovoltaic power generation system is mainly affected by components, inverters, cables, the design inclination of the square array, and the cleanliness of the details. Therefore, the following four aspects can be considered to improve the system's power generation under the condition of specific roof resources: ( 1) Quality product.
Choose products with well-known brands in the industry, reasonable after-sales quality assurance, and obtained monitoring certification; (2) Reduce system loss.
a. Optimize system design: optimize square array design to reduce or avoid shadow occlusion; optimize voltage and current matching between photovoltaic modules and inverters to improve MPPT efficiency;
b, facilitate the transmission loss of various cables and switching devices;
c. Pay attention to reducing component mismatch: component current is divided into gears to reduce the influence of output cables caused by "cask effect" writing. (3) Optimal square array orientation and inclination design
When conditions allow, the optimal orientation and inclination of the square array should be designed as much as possible, and various factors such as roof area resources, installed capacity, convenient maintenance, and investment should be considered, and comprehensive optimization analysis and design should be given. On the premise that the bearing capacity of the color steel roof is satisfied, appropriately increasing the inclination of the square array will help increase the power generation and facilitate later maintenance. (4) Maintenance and cleaning
Regular spray cleaning of components can significantly increase power generation. Conditional units can add a sprinkler system to the components.
6. How to reduce the maintenance cost of a photovoltaic power generation system?
It is recommended to select the system's components and materials with a good reputation in the market, good after-sales service, and qualified products to reduce the incidence of failures. In addition, users should strictly abide by the user manual of the system products and regularly test and clean the system.
7. How to deal with the post-maintenance of the system, how often to maintain it? How to keep it?
According to the product supplier's instruction manual, maintain the parts that must be inspected regularly. The main maintenance work of the system is to wipe the components, and the areas with a lot of water generally do not need manual wiping. In the non-rainy season, cleaning is about once a month, and the amount of dust is relatively low. In large areas, the frequency of cleaning can be increased. In areas with heavy snowfall, the heavy snow should be removed to avoid affecting the power generation, unevenness after snow melting, and timely clean up blocked trees or debris.
8. When cleaning photovoltaic modules, is it enough to rinse with water and wipe? Will there be a risk of electric shock when wiping with water?
To avoid the electric shock injury and possible damage to the human body caused by wiping the module under high temperature and intense light, it is recommended to clean the module in the morning or late afternoon. It is recommended to use a soft brush when cleaning the glass surface of the photovoltaic module, which is clean and gentle. When cleaning, use less force to avoid damage to the glass surface, and components with coated glass should pay attention to prevent damage to the glass layer.
9. How to properly utilize downtime for maintenance?
It is preferred to maintain the system in the early morning or the evening when it is not running in weak light. Before maintenance, take protective measures, wear insulating gloves and use insulating tools.
10. How to determine if a PV module in the PV array is faulty?
When the user finds that the system's power generation has decreased at the same time or compared with the same power generation system installed nearby, the system may be abnormal. If a component is faulty, contact professionals to diagnose the system with professional equipment such as clamp meters and thermal imagers, and finally determine the defective part in the system.
11. Will the shade of houses, leaves, or even bird droppings on the photovoltaic modules affect the power generation system?
The shade of houses, leaves and even bird droppings on the photovoltaic modules will significantly impact the power generation system. The electrical characteristics of the solar cells used in each module are the same. Hot spot effect, the shaded solar cell modules in a series will be used as loads to consume the energy generated by other illuminated solar cell modules. The shaded solar cell modules will heat up at this time, which is the thermal effect phenomenon; this phenomenon is profound. To avoid the hot spot of the series branch, it is necessary to install a bypass diode on the photovoltaic module and prevent the hot spot of the series circuit. In addition, it is required to establish a DC fuse on each photovoltaic string.
12. To prevent the photovoltaic modules from being hit by heavy objects, can a wire protection net be added to the photovoltaic array?
It is not recommended to install iron wire protection nets because installing iron wire protection nets along the photovoltaic array may cause partial shadows on the components, resulting in hot spot effects, which will affect the power generation efficiency of the entire photovoltaic power station. In addition, since qualified photovoltaic modules have passed the ice hockey impact test, the impact under normal circumstances will not affect the module's performance.
13. When the scorching sun is in the sky, do the vulnerable components need to be replaced immediately?
It cannot be replaced immediately. If you want to replace it, it is recommended to perform it in the morning or late afternoon. You should contact the power station operation and maintenance personnel in time, and professionals will go to replace it.
14. Is it necessary to disconnect the photovoltaic power generation system in thunderstorm and lightning protection weather?
Distributed photovoltaic power generation systems are equipped with lightning protection devices, so there is no need to disconnect them. However, for safety reasons, it is recommended to disconnect the circuit breaker switch of the combiner box, cut off the circuit connection with the photovoltaic modules, and avoid the direct lightning strike that the lightning protection module cannot remove. Hazards arising from the failure of the lighting module.
15. Do I need to clean up the photovoltaic power generation system after snow? How to deal with the photovoltaic modules after the snow melts and freezes in winter? Can I step on the modules for cleaning?
If there is heavy snow on the module after snow, it needs to be cleaned. You can use soft objects to push the snow down. However, be careful not to scratch the glass. The module has a specific load-bearing capacity, but you cannot step on the module to clean it, which will cause hidden damage to the module. This is because affecting the life of the components; it is generally recommended not to wait for the snow to be too thick before cleaning to avoid excessive freezing of the members.
16. Can the distributed photovoltaic power generation system resist the harm of hail?
Qualified modules in the photovoltaic grid-connected system must pass strict tests such as the maximum static load (wind load, snow load) on the front of 5400PA, the total static load on the back of 2400PA, and the impact of hail with a diameter of 25MM at a speed of 23M/S seconds. Photovoltaic power generation system brings harm.
17. How to deal with solar cells' temperature rise and ventilation?
The output power of photovoltaic cells will decrease as the temperature rises. Therefore, ventilation and heat dissipation can improve power generation efficiency. The most commonly used method is natural wind ventilation.
18. Does the photovoltaic power generation system have electromagnetic radiation hazards to users?
Photovoltaic power generation system converts solar energy into electric energy according to the principle of photovoltaic effect, which is pollution-free and radiation-free. In addition, electronic devices such as inverters and power distribution cabinets have passed the EMC (electromagnetic compatibility) test, so there is no harm to the human body.
19. Is there any noise hazard in the photovoltaic power generation system?
Photovoltaic power generation system converts solar energy into electrical energy without noise. The noise index of the inverter is not higher than 65 decibels, and there is no noise hazard.
20. What problems should be paid attention to in the fire protection and fire protection of household distributed photovoltaic power generation systems?
It is forbidden to stack flammable and explosive materials near the distributed power generation system. In a fire, the loss of personnel and property is immeasurable. Therefore, in addition to basic fire safety measures, the photovoltaic system is especially reminded that it has self-detection and fire prevention functions to reduce the occurrence of fires. In addition, fire and maintenance passages must be reserved at intervals of up to 40 meters, and there must be easy-to-operate emergency DC system disconnect switches.
21. What are the fire safety measures for distributed photovoltaic systems?
Distributed photovoltaic power plants are mainly built on the roof of buildings. Safety is the primary factor to consider, primarily personal safety and project asset safety. Fire protection measures are mainly based on prevention. On the other hand, an on-site real-time monitoring solution combining civil air defense and technical defense can be adopted: (1) Select an intelligent combiner box with cable temperature sensing to realize fire warning;
(2) Select an intelligent combiner box that can monitor string loop arcing, virtual connection characteristic harmonic analysis, and alarm; (3) Special fire protection system;
(4) When a fire occurs, take appropriate measures to shield the components quickly, cut off the power supply, and disconnect the connection with other equipment.
Part 2: Maintenance knowledge of photovoltaic power station in summer
Summer photovoltaic power station maintenance knowledge
It is said that summer is the best time for power generation. Still, suppose the temperature is too high. The air humidity is too high, coupled with severe weather such as heavy rainfall and thunderstorms. It will often bring adverse effects or even hidden safety hazards to photovoltaic power plants; what should we do?? Today, the editor has compiled some "tips" about maintaining photovoltaic power plants in summer for your reference.
keep ventilated
Whether a module or an inverter, the distribution box must be ventilated to ensure air circulation. For the components of the rooftop photovoltaic power station, it is essential not to unreasonably arrange the arrangement of the photovoltaic power station components to generate more power, causing the members to block each other, and at the same time affecting the heat dissipation and ventilation, resulting in low power generation.
Tip: Be careful if someone tricks you into installing a few more components in a limited area. Reliable brand manufacturers will provide the most practical design on the premise of maximizing power generation according to your roof conditions before installation, rather than requiring you to install a few more components.
Clean up debris in time
To avoid affecting the heat dissipation of the photovoltaic power station, it is necessary to ensure that the photovoltaic modules, inverters, and distribution boxes are open around.
Pay attention to the sun.
Household inverters are generally IP65 protected, with a certain degree of wind, dust, and water resistance. However, when the inverter and distribution box work, they also need to dissipate heat. Therefore, when installing the inverter and distribution box, It is best to install it in a sunshade and rain-proof place. If it must be installed in the open air, make a simple awning for the inverter and power distribution box to prevent direct sunlight. Avoid making the temperature of the inverter and distribution box too high, which will affect the power generation.
Severe Weather Protection
Friends who install photovoltaic power plants must also pay attention to preventing sudden disasters such as lightning, rainstorm, and hail.
1. Lightning strike
If you want to protect against lightning, the most effective and widely used method is to connect the metal parts of electrical equipment to the ground. Electric or gas welding is used for the connection, and welding cannot be used! If welding is not possible on site, riveting or bolting can be used to ensure the contact surface of more than 10 square centimeters, and the buried depth of the grounding body is more than 0.5~0.8m. Remember that the backfill must be compacted.
2. Heavy rain
If your roof is a sloping roof, you don't have to worry. However, if your house has a flat roof, it is best to consider the drainage problem when designing and installing the photovoltaic power station. Avoid when the rainfall is too heavy, the PV modules will be soaked by the rain due to the relatively low bracket installation of the flat roof.
Tips: When inspecting after rain, be sure not to directly touch the connection between the inverter, photovoltaic modules, and power supply cables with your hands, and wear rubber gloves and rubber boots.
3. Hail
Qualified photovoltaic power plant products purchased from large reliable manufacturers, photovoltaic modules have been tested by hail at a speed of 23m/s, so generally, the battery will not affect photovoltaic modules.
However, after the hailstorm, daily inspections are also essential. For example, suppose the power generation of the photovoltaic power station drops significantly, or other abnormal conditions occur after the hailstorm. In that case, the owner must promptly notify the manufacturer's after-sales personnel for inspection.
Regular inspection and cleaning
After the photovoltaic power station is built, the operation and maintenance should not be too sloppy, especially in summer; it is best to conduct regular inspections to ensure that the photovoltaic power station has good heat dissipation, air can be circulated, and weeds and shelters that affect heat dissipation are removed in time. Only this way can the power generation and operation of the photovoltaic power station be guaranteed.
Don't underestimate the maintenance work of home photovoltaics. If you deal with these details, you can generate more electricity per day. Over time, these increased incomes are considerable.
Part 3: Operation management and routine maintenance of photovoltaic power plants
1.Operation management of photovoltaic power plants
1.1. Establish a complete technical document management system
mainly includes:
1 Establish the equipment technical files and design and construction drawing files of the power station
Establish the information management system of the power station
2.Establish the operation period file of the power station
3. Establish power station equipment technical files and design and construction drawings files
mainly includes:
①Design and construction, as-built graphics;
②The basic working principle of the equipment, technical parameters, equipment installation procedures, and equipment debugging steps; ③Description of all operating switches, knobs, handles, and status and signal indications;
④Operation steps for equipment operation;
⑤Items and contents of power station maintenance;
⑥Maintenance schedule and operating procedures for all maintenance items 3. Establish an information management system
⑦Using digital information technology to uniformly calibrate and process the information collection, transmission, processing, and communication of photovoltaic power plants, integrate photovoltaic power plant equipment monitoring management, condition monitoring management systems, and comprehensive automatic protection systems to realize photovoltaic power plant data sharing and remote monitoring.
⑧The photovoltaic power station monitoring system is generally divided into two categories:
a. One is a distributed monitoring system of the wireless network. It is generally used in small and medium-sized rooftop photovoltaic power stations where the installation area is relatively scattered. It adopts block power generation and low-voltage distributed grid connection. Because it adopts GPRS wireless public network transmission, data stability and security are guaranteed. Therefore, it is generally not used in grid-connected photovoltaic power plants with voltage levels of 10 VK and above;
b. The other is the centralized monitoring system of the optical fiber network. It is generally used in large-scale ground photovoltaic or rooftop photovoltaic power plants with grid-connected voltage levels of 10KV and above.
2. Information management system
2.1.Distributed monitoring system of wireless network
Each monitoring sub-station collects the data of photovoltaic grid-connected inverters, electricity meters, and weather stations through RS485 communication, and sends the data to the relevant local server or remote server through various communication methods such as Ethernet/WiFi/GPRS, and then through the network, The client displays data.
Users can also log in to the remote server for real-time remote access to data and display data through network clients, smartphones, and tablet computers.
2.2.Relevant management systems and standards - the basis of information systems
①Clarify the relevant management system and operation and maintenance manual for grid-connected photovoltaic power stations; ②Establish national, local, and industry standards related to the operation and maintenance of photovoltaic power plants (The Solar Energy Research Institute of Sun Yat-sen University, Shunde is compiling the Guangdong local standard "Technical Specifications for the Operation and Maintenance of Grid-connected Photovoltaic Power Stations")
2.3. Strengthen personnel training
Provide training for professional technicians, organize experienced technicians to carry out various internal training on numerous topics given the key and complex problems in operation and maintenance management, and send technicians out for systematic related knowledge training to improve professional skills. Professional skills of technicians;
②Training the operators of the power station. After the workout, they will make them understand and master the basic working principle of the photovoltaic power generation system and the functions of each piece of equipment and should be able to carry out the daily maintenance of the power station as required and have the ability to judge the occurrence of common faults. Causes and the ability to resolve them.
Since March 2014, the solar energy team of Sun Yat-Sen University, in conjunction with Beijing Jianheng, Guangdong Quality Inspection, Guangzhou Aiqiti, and other units, has regularly held training courses on the operation and maintenance of photovoltaic power plants, specializing in technical training personnel in-process and care.
2.4. Establish a smooth information channel
①Set up a particular person responsible for the contact work with the power station operators and equipment manufacturers. When the power station fails, the operator can submit the problem to the relevant departments in time and notify the equipment manufacturer and maintenance personnel to go to the site for repairs in the shortest possible time.
②Comprehensive and complete technical documents and data files should be established for each power station, and a particular person should be set up to be responsible for the management of the technical documents of the power station, to provide technical solid essential data support for the safe and reliable operation of the power station.
3. Daily maintenance of photovoltaic power station
In the operation and management of photovoltaic power stations, the project content of daily care of the power station should be improved
3.1 Photovoltaic array
surface cleaning
Wipe with a soft clean cloth
rradiance below 200 W/m2
Corrosive solvent and hard object wipe
Liquids with a significant temperature difference with the components
Regular inspection, if any problem is found, the part should be adjusted or replaced immediately × broken glass, burning of the backplate, noticeable color change, etc.
Bubble forming a communication channel between circuit connections
The junction box is deformed, twisted, cracked, burned, etc.
The metal frame assembly is well combined with the bracket and is firmly grounded
All bolts, welding, and connections of the stand are firm and reliable, and the anti-corrosion coating on the surface does not crack and fall off.
3.2 DC lightning protection combiner box
Installed in the photovoltaic array, it is mainly used to converge the series DC cables of the photovoltaic modules and then connect with the grid-connected inverter or the DC power distribution cabinet.
①There is no box deformation, rust, water leakage, etc., the safety warning on the outer surface is complete and unbroken, the waterproof lock is flexible in opening and closing, and the fire blocking mud blocking is full;
②The device specifications meet the design requirements, and the electrical connection is good; ③ The positive and negative insulation resistance of the current output busbar to the ground is not more excellent than 2MQ;
④The breaking function of the DC short circuit is flexible and reliable;
⑤Ensure that the lightning arrester is effective.
3.3 Grid-connected inverter
①The structure and electrical connections are kept intact, and there is no corrosion and dust accumulation; ②the warning signs are entire and not damaged;
③The heat dissipation environment should be good. The radiator fans such as modules, reactors, and transformers should be automatically turned on and off according to the temperature. There should be no significant vibration and abnormal noise when the fan runs.
④The AC output side (grid side) circuit breaker should be disconnected once regularly, and the inverter should immediately stop feeding power to the grid;
⑤If the temperature of the DC bus capacitor in the inverter is too high or exceeds the service life, contact the manufacturer and replace it in time (right picture: Infrared thermal imager checks whether the inverter has abnormal temperature)
3.4 High and low voltage power distribution and transformers
①The appearance meets the requirements, and the electrical connections are stable and reliable.
②The insulation resistance of the positive and negative poles of the DC output bus of the DC power distribution cabinet to the ground should be more excellent than 2 MΩ
③The busbar joints in the AC power distribution cabinet are closely connected, and there is no trace of discharge and blackening; the primary contact of the switch has no burning and melting scraps, and the arc extinguishing cover has no burning and blackening and damage; Line-to-ground insulation resistance value, the feeder line must be greater than 0.5 MQ, and the secondary circuit must be greater than 1 MQ.
④The transformer thermometer is in good condition, and the oil temperature is average. The transformer in operation cannot be based on the fact that the oil temperature of the upper layer does not exceed the allowable value, and judged according to the actual situation and operational experience; the oil level of the bushing is average, and there is no discharge trace; the lead wire has no broken strands and joints. No thermal discoloration.
3.5 AC and DC cables, etc.
①The line does not run under overload, and the lead package does not expand, crack, oil seepage, etc.;
②Clean up the accumulations and garbage in the outdoor cable in time; if the cable sheath is damaged, it should be dealt with in time;
③When checking the open ditch of the indoor line, prevent the line from being damaged, and ensure that the bracket is not grounded and has good heat dissipation in the gutter;
④Ensure that the cover plate of the cable trench or cable well is intact, and there should be no accumulated water or debris in the channel; Sunbank provides one-stop services for photovoltaic power generation projects consulting, design, system integration, engineering implementation, operation, and maintenance.
Daily maintenance of photovoltaic power station
1 Maintenance of components and brackets
(1) The surface of photovoltaic modules should be kept clean, and the photovoltaic modules should be wiped with a dry or damp, soft, and clean cloth.
Wipe PV modules with aggressive solvents or complex objects. PV modules should be cleaned when the irradiance is more minor than 200W/m', no.
Using a liquid with a significant temperature difference from the component is advisable to clean the piece.
(2) Photovoltaic modules should be checked regularly. If the following problems are found, the photovoltaic modules should be adjusted or replaced immediately.
Photovoltaic modules have broken glass, scorched backplanes, and noticeable color changes;
The presence of air bubbles in the PV module that form a communication channel with the edge of the module or any electrical circuit;
The photovoltaic module junction box is deformed, twisted, cracked, or burned, and the terminals cannot be in good contact.
(3) The live warning signs on the photovoltaic modules must not be lost.
(4) For photovoltaic modules using a metal frame, the frame and bracket should be well combined, and the contact resistance between the two should not be greater than 4Ω.
The frame must be firmly grounded.
(5) When working without shadows, the solar irradiance is above 500W/m,' and the wind speed is not more than 2m/s
The temperature difference on the outer surface of the same photovoltaic module (the area directly above the cell) should be less than 20℃. Installed capacity greater than 50kWp
The photovoltaic power station should be equipped with an infrared thermal imager to detect the temperature difference on the outer surface of photovoltaic modules.
(6) Use a DC clamp-type ammeter to measure the power connected to the same DC combiner box under the condition that the solar radiation intensity is the same.
The deviation of the input current of each PV module string should not exceed 5%.
(7) All bolts, welds, and bracket connections of the bracket should be firm and reliable, and the anti-corrosion coating on the surface should not crack and fall off
the phenomenon; otherwise, it should not be brushed in time.
2 Maintenance of combiner box
(1) The DC combiner box must not be deformed, corroded, leaked, or deposited, and the safety warning signs on the outer surface of the box should be completed.
The whole is not damaged, and the waterproof lock on the box should be flexible to open and close.
(2) The terminals in the DC combiner box should not be loose or corroded.
(3) The specifications of the high-voltage DC fuses in the DC combiner box should meet the design requirements.
(4) The insulation resistance of the positive pole to the ground and the negative bar to the bottom of the DC output bus should be more excellent than two megohms.
(5) The DC circuit breaker equipped at the DC output bus terminal should have flexible and reliable braking functions.
(6) The lightning arrester in the DC combiner box should be adequate.
3 Maintenance of DC power distribution cabinet
(1) The DC power distribution cabinet shall not be deformed, corroded, leaked, or deposited, and the safety warning signs on the outer surface of the box shall be completed.
The whole is not damaged, and the waterproof lock on the box should be flexible to open.
(2) The terminals in the DC distribution cabinet should not be loose or corroded.
(3) The insulation resistance of the positive pole to the ground and the negative bar to the bottom of the DC output bus should be more excellent than two megohms.
(4) The connection between the DC input interface of the DC power distribution cabinet and the combiner box should be stable and reliable
(5) The connection between the DC power distribution cabinet's DC output and the grid-connected host's DC input should be stable and reliable.
(6) The action of the DC power distribution cabinet's DC circuit breaker should be flexible, and the performance should be stable and reliable.
(7) The lightning arrester configured on the output side of the DC bus should be adequate.
4 Maintenance of the inverter
(1) The inverter structure and electrical connections should be kept intact, with no corrosion, dust accumulation, etc. In addition, the heat dissipation environment should be good.
There should be no significant vibration and abnormal noise when the inverter runs.
(2) The warning signs on the inverter should be intact and not damaged.
(3) The cooling fans of the modules, reactors, and transformers in the inverter should start and stop automatically according to the temperature.
There should be no significant vibration and abnormal noise when the cooling fan runs.
(4) Disconnect the circuit breaker regularly on the AC output side (grid side), and the inverter should immediately stop feeding power to the grid.
(5) The temperature of the DC bus capacitor in the inverter is too high or exceeds the service life and should be replaced in time.
5 Maintenance of AC power distribution cabinet
(1) Ensure that the metal frame of the power distribution cabinet and the bare steel is connected with galvanized bolts and the anti-loosening parts are complete.
(2) The identification devices of the power distribution cabinet indicating the number, name, or operation position of the controlled equipment should be complete, and the number should be clear and neat.
(3) The busbar joints should be tightly connected, without deformation, without blackening discharge traces, and without looseness and damage to the insulation. Tighten the connecting bolts.
Rust free.
(4) The push-pull of the handcart and the withdrawable complete set of power distribution cabinets should be flexible, and there should be no jamming and collision phenomenon.
Consistent, and the contacts are in close contact.
(5) The switches and primary contacts in the power distribution cabinet have no burning marks, and the arc extinguishing cover has no blazing black and damage. Tighten the wiring screws and clean the cabinet.
Dust inside.
(6) Take out each sub-switch cabinet from the drawer, and fasten each terminal. Check current transformers, ammeters, watt-hour meters
Installation and wiring, the handle operating mechanism should be flexible and reliable, tighten the circuit breaker inlet and outlet lines, clean the switch cabinet and the back of the power distribution cabinet.
Dust at the pinout.
(7) The heat dissipation of the heating objects of low-voltage electrical appliances should be good, the switching pressure plate should be released well, and the signal lights, buttons, lights of the signal circuit should be well
The signs, electric bells, flashlights, accident electric bells, and other actions and signals should be displayed accurately.
(8) Inspect the insulation resistance value between lines and between lines and ground between cabinets, screens, platforms, boxes, and panels, and the feeder lines must be greater than 0.5M 92,
The secondary loop must be greater than 1M.
6 Transformer Maintenance
(1) The thermometer of the transformer should be in good condition, the oil temperature should be average, the oil level of the oil conservator should correspond to the ambient temperature, and there should be no
Seepage, oil leakage. The load size, cooling conditions, and seasons of each transformer may be different, and the transformer in operation cannot be more than
The oil temperature of the layer should not exceed the allowable value. It should also be compared with the previous oil temperature based on the prior operating experience and the above conditions.
(2) The oil level of the casing should be expected, and there should be no damage, cracks, severe oil pollution, discharge marks, and other abnormal phenomena on the outside of the casing.
The oil quality should be transparent and slightly yellowish, from which the quality of the oil can be judged. In addition, the oil level should conform to the standard line of ambient temperatures, such as oil level.
If it is too low, check the transformer for oil leakage, etc. If the oil level is too high, limit the use of the cooling device to see if there is an internal failure.
(3) The sound response of the transformer is normal, and there is generally a uniform humming electromagnetic sound during regular operation. If the sound is abnormal, be careful
Check, make sound judgments, and deal with them immediately.
(4) There should be no broken strands in the transformer leads, no overheating or discoloration of the joints, or melting (discoloration) of the temperature indicator. In addition, the respirator should be in good condition.
The degree of discoloration of silica gel should not exceed 3/4.
(5) The tap position and power indication of the excitation tap changer should be expected, there should be no gas in the Buchholz relay, and the transformer should
The shell grounding and iron core grounding should be in good condition.
(6) In severe weather, special inspections should be carried out. For example, check whether the lead swings violently and whether the sag is sufficient when the wind is strong.
There should be no debris at the top cover of the transformer and the leads of the bushing. In heavy snow, the contacts of each part should not melt or have discharge immediately after the snowfalls.
Elephant. On foggy days, whether there is spark discharge in each department, etc.
7 Maintenance of cables
(1) The cable should not run under overload, and the lead pack of the line should not expand or crack.
(2) The parts of the cables entering and leaving the equipment should be sealed well, and there should be no holes with a diameter greater than 10 mm. Otherwise, they should be blocked with fire-blocking mud walls.
(3) Where the cable has too much pressure and tension on the equipment shell, the support point of the line should be intact.
(4) There should be no perforations, cracks, and significant unevenness at the mouth of the cable protection steel pipe, the inner wall should be smooth, and the metal cable pipe should not be
There should be no burrs, complex objects, and garbage if there is severe rust.
(5) The accumulations and garbage in the outdoor cable well should be cleaned up in time. If the cable sheath is damaged, it should be dealt with.
(6) When checking the open trench of indoor cables, it is necessary to prevent damage to the line and ensure that the bracket is grounded and the heat dissipation in the track is good.
(7) The stakes along the direct buried cable line should be intact, and there should be no excavation on the ground near the route to ensure that there are no piles on the floor along the way.
To ensure that the outdoor exposed ground cable protection facilities are intact, place heavy objects, building materials, and temporary facilities without discharging corrosive substances.
(8) Ensure that the cover plate of the cable trench or cable well is intact, there should be no accumulated water or debris in the channel, and ensure that the brackets in the track should be firmly
Whether there is rust or looseness, the sheath and armor of the armored cable should not be severely rusted.
(9) For multiple cables laid in parallel, the cable sheath's current distribution and temperature should be checked to prevent electrical failure due to poor contact.
The cable has burned out the connection point.
(10) Ensure that the cable terminals are well-grounded, the insulating sleeves are intact, clean, and have no traces of flashover discharge, and ensure that the cables are in the same color.
Obvious.
8 Extreme Weather Maintenance
(1) If the trip occurs when it rains, it may be that the wiring head is not tight. If such a situation arises, it must be dealt with after the rain and sunny days.
Use insulating tape to wrap the terminals and observe whether the tripping occurs. If the tripping phenomenon continues, you should contact the maintenance center or local electricity.
Station report.
(2) During thunderstorms, the air switch below the meter should be turned off to prevent damage to electrical equipment. After the thunderstorm, turn the switch on again
Close up.
1. Regularly check whether the connection between the photovoltaic modules is firm; 2. Whether the link in the square array junction box is firm;
3. Check whether the photovoltaic modules are damaged or abnormal; 4. Check whether the connection between the square array supports firm; 5. Whether the relationship between the support and the grounding system is reliable;
6. Whether the connection between the cable metal sheath and the grounding system is reliable, etc.;
Chapter 1: Daily maintenance of photovoltaic power plants
According to reports, photovoltaic power plants' daily operation and maintenance mainly include 1. Regularly check whether the connection between the photovoltaic modules is firm; 2. Whether the connection in the square array junction box is firm; 3. Check whether the photovoltaic modules are damaged or abnormal; 4. Check whether the connection between the phalanx supports is firm; 5. Whether the connection between the support and the grounding system is reliable;
6. Whether the connection between the cable metal sheath and the grounding system is reliable, etc.;
1. Maintenance of photovoltaic modules
Usually, a hot spot detection is carried out once a month, and a bracket test is carried out once every two months (depending on the situation of the power station). Investigate immediately to find the cause and fix it. As we all know, photovoltaic power generation needs to rely on sunlight to generate electricity. Therefore, the efficiency of power generation depends largely on the cleanliness of the panels. If there is too much dust and dirt on the surface of photovoltaic modules, the average photovoltaic power generation efficiency will drop by 15% or more. Therefore, it is necessary to clean the photovoltaic modules regularly. "As for the frequency of cleaning, it depends on the situation of the power station. Once the power generation drops by about 5%, it should be cleaned immediately."
Note: The best cleaning time is morning and evening;
2. Maintenance of the inverter
As a bridge of the photovoltaic system, the cost of the inverter in the entire system has been minimal, but its role cannot be ignored. Therefore, the maintenance of the inverter has also become an essential part of the operation and maintenance of the photovoltaic power station.
1. Regularly clean the dust on the inverter box; 2. Regularly clean the dirt in the inverter vent;
PV Power Plant Maintenance Manual
1.The use and maintenance of solar cell array
(1) The solar cell array should be installed where there are no high buildings, trees, poles, etc., to block the sunlight to obtain sunlight fully. My country is located in the northern hemisphere, the lighting surface of the square array should be placed in the south, and the inclination angle can be appropriately increased by 5°-15° compared with the local latitude. The installed angle between the Shanghai area is 38OC.
(2) During the transportation, installation, and use of the solar cell array, the components should be handled with care, and collision, knocking, and scratching are strictly prohibited not to damage the encapsulating glass, affecting the performance, and shorten the lifespan.
(3) The lighting surface of the solar cell array should always be kept clean. If there is dust or other dirt, it should be rinsed with water first and then wiped off the water with sterile gauze. Do not rinse with complex objects or corrosive solvents. , wipe.
(4) Pay attention to the positive and negative polarities of the output connection of the solar cell array, and do not reverse it. (6) The solar cell phalanx, whose angle can be adjusted manually, should adjust the sunward inclination and azimuth angle of the phalanx bracket according to the changes of seasons to make full use of the solar energy, except when it must be fixed.
(7) The photoelectric parameters of the solar cell array should be detected irregularly by the appropriate methods during use. If problems are found, they should be solved in time to ensure an uninterrupted power supply of the phalanx.
(8) Guardrails or walls should be added around the solar cell array and its supporting equipment to avoid an animal or human damage. In areas with heavy lightning or high mountains, grounding, lightning arresters, and lightning rods should be installed to prevent lightning strikes.
2.Control inverter usage precautions and maintenance
1) During installation, operation, and routine maintenance, do not directly contact high voltage positive and negative electrodes. At the same time, care should be taken not to leave tools and other sundries in the control cabinet to avoid short-circuit failure.
2) The working environment of the equipment should be dry, ventilated, and moisture-proof.
3) The cabinet should be kept clean. If it is found that there is a lot of dust, it should be cleaned in time after the power is turned off to avoid excessive dust and reduce the insulation strength.
4) Pay attention to various status displays in the computer and regularly report the inverter data to relevant experts and professional technicians for analysis to ensure timely detection and prevention of accidents.
5) During transportation, first remove all wiring, and it is strictly forbidden to collide, and do not turn it upside down. Next, the machine should be placed in a well-ventilated place, with the back and sides at least 10 cm away from the wall, so that the incoming and outgoing air can be kept unobstructed. Avoid placing in direct sunlight. It should be kept away from fire sources and high temperatures to prevent the temperature from being too high, and the indoor temperature should not exceed 40 ℃. Finally, avoid placing in a corrosive gas environment.
6) Pay attention to various status displays in the computer and regularly report the inverter data to relevant experts and professional technicians for analysis to ensure timely detection and prevention of accidents.
7) Maintenance and overhaul
a. Regularly check whether the wiring of each part of the inverter is firm, whether there is a looseness and overheating, and especially carefully check the grounding of fans, power modules, input terminals, and output terminals.
b. If there is an alarm and stop, it is not allowed to start the machine immediately. The reason should be found out and repaired before starting the engine. The inspection should be carried out according to the steps specified in the inverter maintenance manual.
c. Operators must be specially trained to be able to judge the causes of general faults promptly and eliminate them, such as being able to replace fuses, components, and damaged circuit boards skillfully. Therefore, untrained personnel is not allowed to operate the equipment.
d. If there is an accident that cannot be easily eliminated or the cause of the accident is unknown, detailed records of the accident shall be made, and the data recorded in the computer shall be backed up in time and submitted to the contractor together to solve the problem as quickly as possible.
Maintenance staff training
Training work is vital to ensure the daily maintenance of the power station, and the training objects are mainly the personnel arranged by the local power management system. Therefore, there are mainly two parts: basic knowledge training and practical operation training.
The main content of the basic knowledge training is the knowledge of solar energy systems, macro aspects such as engineering design, installation and debugging, etc., to guide the relevant personnel of the power station to have a systematic and comprehensive understanding of the power station. In addition, practical operation training is held on-site. Through on-site training and practical operation guidance, operators can better grasp relevant capabilities.
To enable the trainees designated by the developer to master the training knowledge and skills from the combination of theory and practice, the trainees should participate in the installation and commissioning of the project and obey the unified command and dispatch of the project headquarters during the construction process.
To deepen the training effect, the technical supervisors arranged by the contractor should have at least a college degree or above, graduated from mechanical and electrical majors, or other professionals with practical experience in solar system installation. During the actual installation and commissioning process, knowledge lectures can be held for local personnel.
The company is willing to provide extensive and timely technical support for system users during the construction period, including technical consultation and voluntary training.
After the completion and acceptance of the project, the contractor will continue to provide after-sales training services for the power station, whether within the warranty period or outside the warranty period.
After-sales service content
1. Obligation to provide technical advice
2. Supply spare parts and guarantee the delivery within 48 hours after confirmation;
3. During the system's warranty period, the faulty parts will be replaced free of charge, and the accessories fee not exceeding the transaction price of this contract will be charged outside the warranty period. Technical support and maintenance service guarantee
The contractor's commitment to the power station system warranty period: 3 years for the system, five years for the solar cell module, and three years for the controller.
During the warranty period, the warranty content of the power generation system:
Due to improper design, installation, and guidance. The performance parameters of the equipment or spare parts provided by the power supply cannot meet the design index requirements; the system or equipment fails due to lightning.
During the warranty period, the warranty contents of essential equipment: a. Warranty contents of solar cell modules: the power output drops significantly; there is a short circuit or open circuit in a single module;
The glass bursts naturally (except those exceeding the environmental index), and the junction box falls off. b. Warranty content of the controller: the output voltage exceeds the stable range; the output power fails to meet the index requirements; failure to effectively ground causes an accident;
For any faults within the scope of the warranty, the contractor will send personnel to solve and replace equipment and spare parts on-site free of charge.
Any losses caused by human error, natural disasters, artificial damage, or failure to effectively implement the protective measures proposed by the contractor are not covered by the warranty. However, the company promises that as long as the fault is reported for repair, it will send someone to repair it and charge appropriate fees. In addition, the cost of accessories and equipment will not exceed the transaction price of this contract.
Operation and Maintenance
1. What are the common faults of distributed photovoltaic power generation systems? What are the typical problems that may occur in various system components?
The inverter cannot work and cannot be started because the voltage does not reach the startup setting value, and the power generation is low due to the components or the inverter. Typical problems in the system components include the burning of the junction box and the partial burning of the details.
2. What is the PID phenomenon? In what environment will the distributed photovoltaic power generation system occur? How to diagnose and avoid the impact?
PID (Potential Induced Degradation), also known as "potential induced degradation," refers to the power degradation of photovoltaic modules induced by external factors. According to the mechanism of PID phenomenon, module manufacturers have developed a series of production processes to prevent the occurrence of PID phenomenon, including using anti-PID cells, increasing the volume resistivity of module composite materials, reducing the water vapor transmission rate of materials, photovoltaic systems Negative grounding, double-glass frameless components, etc., verified by tests and actual system operation data, even if the photovoltaic power generation system is built in a high temperature and high humidity environment, the generation of PID can be well avoided.
3. How long is the lifespan of a distributed photovoltaic power generation system?
The core components of photovoltaic modules have a life span of more than 25 years, and photovoltaic inverters are generally more than five years old. For details, please refer to the warranty policy. 4. What main factors lead to the decline and loss of photovoltaic power generation system efficiency?
The efficiency of the photovoltaic power generation system is lost due to external influences, including shading, gray layer, component attenuation, temperature influence, component matching, MPPT accuracy, inverter efficiency, transformer efficiency, DC and AC line losses, etc.
The influence of each factor on efficiency is also different. Therefore, in the early stage of the project, attention should be paid to the optimal design of the system, and specific measures should be taken during the operation of the project to reduce the impact of dust and other obstructions on the system.
5. In the case of specific roof resources, how to increase the power generation of the distributed photovoltaic power generation system?
The power generation of the distributed photovoltaic power generation system is mainly affected by components, inverters, cables, the design inclination of the square array, and the cleanliness of the details. Therefore, the following four aspects can be considered to improve the system's power generation under the condition of specific roof resources: ( 1) Quality product.
Choose products with well-known brands in the industry, reasonable after-sales quality assurance, and obtained monitoring certification; (2) Reduce system loss.
a. Optimize system design: optimize square array design to reduce or avoid shadow occlusion; optimize voltage and current matching between photovoltaic modules and inverters to improve MPPT efficiency;
b, facilitate the transmission loss of various cables and switching devices;
c. Pay attention to reducing component mismatch: component current is divided into gears to reduce the influence of output cables caused by "cask effect" writing. (3) Optimal square array orientation and inclination design
When conditions allow, the optimal orientation and inclination of the square array should be designed as much as possible, and various factors such as roof area resources, installed capacity, convenient maintenance, and investment should be considered, and comprehensive optimization analysis and design should be given. On the premise that the bearing capacity of the color steel roof is satisfied, appropriately increasing the inclination of the square array will help increase the power generation and facilitate later maintenance. (4) Maintenance and cleaning
Regular spray cleaning of components can significantly increase power generation. Conditional units can add a sprinkler system to the components.
6. How to reduce the maintenance cost of a photovoltaic power generation system?
It is recommended to select the system's components and materials with a good reputation in the market, good after-sales service, and qualified products to reduce the incidence of failures. In addition, users should strictly abide by the user manual of the system products and regularly test and clean the system.
7. How to deal with the post-maintenance of the system, how often to maintain it? How to keep it?
According to the product supplier's instruction manual, maintain the parts that must be inspected regularly. The main maintenance work of the system is to wipe the components, and the areas with a lot of water generally do not need manual wiping. In the non-rainy season, cleaning is about once a month, and the amount of dust is relatively low. In large areas, the frequency of cleaning can be increased. In areas with heavy snowfall, the heavy snow should be removed to avoid affecting the power generation, unevenness after snow melting, and timely clean up blocked trees or debris.
8. When cleaning photovoltaic modules, is it enough to rinse with water and wipe? Will there be a risk of electric shock when wiping with water?
To avoid the electric shock injury and possible damage to the human body caused by wiping the module under high temperature and intense light, it is recommended to clean the module in the morning or late afternoon. It is recommended to use a soft brush when cleaning the glass surface of the photovoltaic module, which is clean and gentle. When cleaning, use less force to avoid damage to the glass surface, and components with coated glass should pay attention to prevent damage to the glass layer.
9. How to properly utilize downtime for maintenance?
It is preferred to maintain the system in the early morning or the evening when it is not running in weak light. Before maintenance, take protective measures, wear insulating gloves and use insulating tools.
10. How to determine if a PV module in the PV array is faulty?
When the user finds that the system's power generation has decreased at the same time or compared with the same power generation system installed nearby, the system may be abnormal. If a component is faulty, contact professionals to diagnose the system with professional equipment such as clamp meters and thermal imagers, and finally determine the defective part in the system.
11. Will the shade of houses, leaves, or even bird droppings on the photovoltaic modules affect the power generation system?
The shade of houses, leaves and even bird droppings on the photovoltaic modules will significantly impact the power generation system. The electrical characteristics of the solar cells used in each module are the same. Hot spot effect, the shaded solar cell modules in a series will be used as loads to consume the energy generated by other illuminated solar cell modules. The shaded solar cell modules will heat up at this time, which is the thermal effect phenomenon; this phenomenon is profound. To avoid the hot spot of the series branch, it is necessary to install a bypass diode on the photovoltaic module and prevent the hot spot of the series circuit. In addition, it is required to establish a DC fuse on each photovoltaic string.
12. To prevent the photovoltaic modules from being hit by heavy objects, can a wire protection net be added to the photovoltaic array?
It is not recommended to install iron wire protection nets because installing iron wire protection nets along the photovoltaic array may cause partial shadows on the components, resulting in hot spot effects, which will affect the power generation efficiency of the entire photovoltaic power station. In addition, since qualified photovoltaic modules have passed the ice hockey impact test, the impact under normal circumstances will not affect the module's performance.
13. When the scorching sun is in the sky, do the vulnerable components need to be replaced immediately?
It cannot be replaced immediately. If you want to replace it, it is recommended to perform it in the morning or late afternoon. You should contact the power station operation and maintenance personnel in time, and professionals will go to replace it.
14. Is it necessary to disconnect the photovoltaic power generation system in thunderstorm and lightning protection weather?
Distributed photovoltaic power generation systems are equipped with lightning protection devices, so there is no need to disconnect them. However, for safety reasons, it is recommended to disconnect the circuit breaker switch of the combiner box, cut off the circuit connection with the photovoltaic modules, and avoid the direct lightning strike that the lightning protection module cannot remove. Hazards arising from the failure of the lighting module.
15. Do I need to clean up the photovoltaic power generation system after snow? How to deal with the photovoltaic modules after the snow melts and freezes in winter? Can I step on the modules for cleaning?
If there is heavy snow on the module after snow, it needs to be cleaned. You can use soft objects to push the snow down. However, be careful not to scratch the glass. The module has a specific load-bearing capacity, but you cannot step on the module to clean it, which will cause hidden damage to the module. This is because affecting the life of the components; it is generally recommended not to wait for the snow to be too thick before cleaning to avoid excessive freezing of the members.
16. Can the distributed photovoltaic power generation system resist the harm of hail?
Qualified modules in the photovoltaic grid-connected system must pass strict tests such as the maximum static load (wind load, snow load) on the front of 5400PA, the total static load on the back of 2400PA, and the impact of hail with a diameter of 25MM at a speed of 23M/S seconds. Photovoltaic power generation system brings harm.
17. How to deal with solar cells' temperature rise and ventilation?
The output power of photovoltaic cells will decrease as the temperature rises. Therefore, ventilation and heat dissipation can improve power generation efficiency. The most commonly used method is natural wind ventilation.
18. Does the photovoltaic power generation system have electromagnetic radiation hazards to users?
Photovoltaic power generation system converts solar energy into electric energy according to the principle of photovoltaic effect, which is pollution-free and radiation-free. In addition, electronic devices such as inverters and power distribution cabinets have passed the EMC (electromagnetic compatibility) test, so there is no harm to the human body.
19. Is there any noise hazard in the photovoltaic power generation system?
Photovoltaic power generation system converts solar energy into electrical energy without noise. The noise index of the inverter is not higher than 65 decibels, and there is no noise hazard.
20. What problems should be paid attention to in the fire protection and fire protection of household distributed photovoltaic power generation systems?
It is forbidden to stack flammable and explosive materials near the distributed power generation system. In a fire, the loss of personnel and property is immeasurable. Therefore, in addition to basic fire safety measures, the photovoltaic system is especially reminded that it has self-detection and fire prevention functions to reduce the occurrence of fires. In addition, fire and maintenance passages must be reserved at intervals of up to 40 meters, and there must be easy-to-operate emergency DC system disconnect switches.
21. What are the fire safety measures for distributed photovoltaic systems?
Distributed photovoltaic power plants are mainly built on the roof of buildings. Safety is the primary factor to consider, primarily personal safety and project asset safety. Fire protection measures are mainly based on prevention. On the other hand, an on-site real-time monitoring solution combining civil air defense and technical defense can be adopted: (1) Select an intelligent combiner box with cable temperature sensing to realize fire warning;
(2) Select an intelligent combiner box that can monitor string loop arcing, virtual connection characteristic harmonic analysis, and alarm; (3) Special fire protection system;
(4) When a fire occurs, take appropriate measures to shield the components quickly, cut off the power supply, and disconnect the connection with other equipment.
Part 2: Maintenance knowledge of photovoltaic power station in summer
Summer photovoltaic power station maintenance knowledge
It is said that summer is the best time for power generation. Still, suppose the temperature is too high. The air humidity is too high, coupled with severe weather such as heavy rainfall and thunderstorms. It will often bring adverse effects or even hidden safety hazards to photovoltaic power plants; what should we do?? Today, the editor has compiled some "tips" about maintaining photovoltaic power plants in summer for your reference.
keep ventilated
Whether a module or an inverter, the distribution box must be ventilated to ensure air circulation. For the components of the rooftop photovoltaic power station, it is essential not to unreasonably arrange the arrangement of the photovoltaic power station components to generate more power, causing the members to block each other, and at the same time affecting the heat dissipation and ventilation, resulting in low power generation.
Tip: Be careful if someone tricks you into installing a few more components in a limited area. Reliable brand manufacturers will provide the most practical design on the premise of maximizing power generation according to your roof conditions before installation, rather than requiring you to install a few more components.
Clean up debris in time
To avoid affecting the heat dissipation of the photovoltaic power station, it is necessary to ensure that the photovoltaic modules, inverters, and distribution boxes are open around.
Pay attention to the sun.
Household inverters are generally IP65 protected, with a certain degree of wind, dust, and water resistance. However, when the inverter and distribution box work, they also need to dissipate heat. Therefore, when installing the inverter and distribution box, It is best to install it in a sunshade and rain-proof place. If it must be installed in the open air, make a simple awning for the inverter and power distribution box to prevent direct sunlight. Avoid making the temperature of the inverter and distribution box too high, which will affect the power generation.
Severe Weather Protection
Friends who install photovoltaic power plants must also pay attention to preventing sudden disasters such as lightning, rainstorm, and hail.
1. Lightning strike
If you want to protect against lightning, the most effective and widely used method is to connect the metal parts of electrical equipment to the ground. Electric or gas welding is used for the connection, and welding cannot be used! If welding is not possible on site, riveting or bolting can be used to ensure the contact surface of more than 10 square centimeters, and the buried depth of the grounding body is more than 0.5~0.8m. Remember that the backfill must be compacted.
2. Heavy rain
If your roof is a sloping roof, you don't have to worry. However, if your house has a flat roof, it is best to consider the drainage problem when designing and installing the photovoltaic power station. Avoid when the rainfall is too heavy, the PV modules will be soaked by the rain due to the relatively low bracket installation of the flat roof.
Tips: When inspecting after rain, be sure not to directly touch the connection between the inverter, photovoltaic modules, and power supply cables with your hands, and wear rubber gloves and rubber boots.
3. Hail
Qualified photovoltaic power plant products purchased from large reliable manufacturers, photovoltaic modules have been tested by hail at a speed of 23m/s, so generally, the battery will not affect photovoltaic modules.
However, after the hailstorm, daily inspections are also essential. For example, suppose the power generation of the photovoltaic power station drops significantly, or other abnormal conditions occur after the hailstorm. In that case, the owner must promptly notify the manufacturer's after-sales personnel for inspection.
Regular inspection and cleaning
After the photovoltaic power station is built, the operation and maintenance should not be too sloppy, especially in summer; it is best to conduct regular inspections to ensure that the photovoltaic power station has good heat dissipation, air can be circulated, and weeds and shelters that affect heat dissipation are removed in time. Only this way can the power generation and operation of the photovoltaic power station be guaranteed.
Don't underestimate the maintenance work of home photovoltaics. If you deal with these details, you can generate more electricity per day. Over time, these increased incomes are considerable.
Part 3: Operation management and routine maintenance of photovoltaic power plants
1.Operation management of photovoltaic power plants
1.1. Establish a complete technical document management system
mainly includes:
1 Establish the equipment technical files and design and construction drawing files of the power station
Establish the information management system of the power station
2.Establish the operation period file of the power station
3. Establish power station equipment technical files and design and construction drawings files
mainly includes:
①Design and construction, as-built graphics;
②The basic working principle of the equipment, technical parameters, equipment installation procedures, and equipment debugging steps; ③Description of all operating switches, knobs, handles, and status and signal indications;
④Operation steps for equipment operation;
⑤Items and contents of power station maintenance;
⑥Maintenance schedule and operating procedures for all maintenance items 3. Establish an information management system
⑦Using digital information technology to uniformly calibrate and process the information collection, transmission, processing, and communication of photovoltaic power plants, integrate photovoltaic power plant equipment monitoring management, condition monitoring management systems, and comprehensive automatic protection systems to realize photovoltaic power plant data sharing and remote monitoring.
⑧The photovoltaic power station monitoring system is generally divided into two categories:
a. One is a distributed monitoring system of the wireless network. It is generally used in small and medium-sized rooftop photovoltaic power stations where the installation area is relatively scattered. It adopts block power generation and low-voltage distributed grid connection. Because it adopts GPRS wireless public network transmission, data stability and security are guaranteed. Therefore, it is generally not used in grid-connected photovoltaic power plants with voltage levels of 10 VK and above;
b. The other is the centralized monitoring system of the optical fiber network. It is generally used in large-scale ground photovoltaic or rooftop photovoltaic power plants with grid-connected voltage levels of 10KV and above.
2. Information management system
2.1.Distributed monitoring system of wireless network
Each monitoring sub-station collects the data of photovoltaic grid-connected inverters, electricity meters, and weather stations through RS485 communication, and sends the data to the relevant local server or remote server through various communication methods such as Ethernet/WiFi/GPRS, and then through the network, The client displays data.
Users can also log in to the remote server for real-time remote access to data and display data through network clients, smartphones, and tablet computers.
2.2.Relevant management systems and standards - the basis of information systems
①Clarify the relevant management system and operation and maintenance manual for grid-connected photovoltaic power stations; ②Establish national, local, and industry standards related to the operation and maintenance of photovoltaic power plants (The Solar Energy Research Institute of Sun Yat-sen University, Shunde is compiling the Guangdong local standard "Technical Specifications for the Operation and Maintenance of Grid-connected Photovoltaic Power Stations")
2.3. Strengthen personnel training
Provide training for professional technicians, organize experienced technicians to carry out various internal training on numerous topics given the key and complex problems in operation and maintenance management, and send technicians out for systematic related knowledge training to improve professional skills. Professional skills of technicians;
②Training the operators of the power station. After the workout, they will make them understand and master the basic working principle of the photovoltaic power generation system and the functions of each piece of equipment and should be able to carry out the daily maintenance of the power station as required and have the ability to judge the occurrence of common faults. Causes and the ability to resolve them.
Since March 2014, the solar energy team of Sun Yat-Sen University, in conjunction with Beijing Jianheng, Guangdong Quality Inspection, Guangzhou Aiqiti, and other units, has regularly held training courses on the operation and maintenance of photovoltaic power plants, specializing in technical training personnel in-process and care.
2.4. Establish a smooth information channel
①Set up a particular person responsible for the contact work with the power station operators and equipment manufacturers. When the power station fails, the operator can submit the problem to the relevant departments in time and notify the equipment manufacturer and maintenance personnel to go to the site for repairs in the shortest possible time.
②Comprehensive and complete technical documents and data files should be established for each power station, and a particular person should be set up to be responsible for the management of the technical documents of the power station, to provide technical solid essential data support for the safe and reliable operation of the power station.
3. Daily maintenance of photovoltaic power station
In the operation and management of photovoltaic power stations, the project content of daily care of the power station should be improved
3.1 Photovoltaic array
surface cleaning
Wipe with a soft clean cloth
rradiance below 200 W/m2
Corrosive solvent and hard object wipe
Liquids with a significant temperature difference with the components
Regular inspection, if any problem is found, the part should be adjusted or replaced immediately × broken glass, burning of the backplate, noticeable color change, etc.
Bubble forming a communication channel between circuit connections
The junction box is deformed, twisted, cracked, burned, etc.
The metal frame assembly is well combined with the bracket and is firmly grounded
All bolts, welding, and connections of the stand are firm and reliable, and the anti-corrosion coating on the surface does not crack and fall off.
3.2 DC lightning protection combiner box
Installed in the photovoltaic array, it is mainly used to converge the series DC cables of the photovoltaic modules and then connect with the grid-connected inverter or the DC power distribution cabinet.
①There is no box deformation, rust, water leakage, etc., the safety warning on the outer surface is complete and unbroken, the waterproof lock is flexible in opening and closing, and the fire blocking mud blocking is full;
②The device specifications meet the design requirements, and the electrical connection is good; ③ The positive and negative insulation resistance of the current output busbar to the ground is not more excellent than 2MQ;
④The breaking function of the DC short circuit is flexible and reliable;
⑤Ensure that the lightning arrester is effective.
3.3 Grid-connected inverter
①The structure and electrical connections are kept intact, and there is no corrosion and dust accumulation; ②the warning signs are entire and not damaged;
③The heat dissipation environment should be good. The radiator fans such as modules, reactors, and transformers should be automatically turned on and off according to the temperature. There should be no significant vibration and abnormal noise when the fan runs.
④The AC output side (grid side) circuit breaker should be disconnected once regularly, and the inverter should immediately stop feeding power to the grid;
⑤If the temperature of the DC bus capacitor in the inverter is too high or exceeds the service life, contact the manufacturer and replace it in time (right picture: Infrared thermal imager checks whether the inverter has abnormal temperature)
3.4 High and low voltage power distribution and transformers
①The appearance meets the requirements, and the electrical connections are stable and reliable.
②The insulation resistance of the positive and negative poles of the DC output bus of the DC power distribution cabinet to the ground should be more excellent than 2 MΩ
③The busbar joints in the AC power distribution cabinet are closely connected, and there is no trace of discharge and blackening; the primary contact of the switch has no burning and melting scraps, and the arc extinguishing cover has no burning and blackening and damage; Line-to-ground insulation resistance value, the feeder line must be greater than 0.5 MQ, and the secondary circuit must be greater than 1 MQ.
④The transformer thermometer is in good condition, and the oil temperature is average. The transformer in operation cannot be based on the fact that the oil temperature of the upper layer does not exceed the allowable value, and judged according to the actual situation and operational experience; the oil level of the bushing is average, and there is no discharge trace; the lead wire has no broken strands and joints. No thermal discoloration.
3.5 AC and DC cables, etc.
①The line does not run under overload, and the lead package does not expand, crack, oil seepage, etc.;
②Clean up the accumulations and garbage in the outdoor cable in time; if the cable sheath is damaged, it should be dealt with in time;
③When checking the open ditch of the indoor line, prevent the line from being damaged, and ensure that the bracket is not grounded and has good heat dissipation in the gutter;
④Ensure that the cover plate of the cable trench or cable well is intact, and there should be no accumulated water or debris in the channel; Sunbank provides one-stop services for photovoltaic power generation projects consulting, design, system integration, engineering implementation, operation, and maintenance.
Daily maintenance of photovoltaic power station
1 Maintenance of components and brackets
(1) The surface of photovoltaic modules should be kept clean, and the photovoltaic modules should be wiped with a dry or damp, soft, and clean cloth.
Wipe PV modules with aggressive solvents or complex objects. PV modules should be cleaned when the irradiance is more minor than 200W/m', no.
Using a liquid with a significant temperature difference from the component is advisable to clean the piece.
(2) Photovoltaic modules should be checked regularly. If the following problems are found, the photovoltaic modules should be adjusted or replaced immediately.
Photovoltaic modules have broken glass, scorched backplanes, and noticeable color changes;
The presence of air bubbles in the PV module that form a communication channel with the edge of the module or any electrical circuit;
The photovoltaic module junction box is deformed, twisted, cracked, or burned, and the terminals cannot be in good contact.
(3) The live warning signs on the photovoltaic modules must not be lost.
(4) For photovoltaic modules using a metal frame, the frame and bracket should be well combined, and the contact resistance between the two should not be greater than 4Ω.
The frame must be firmly grounded.
(5) When working without shadows, the solar irradiance is above 500W/m,' and the wind speed is not more than 2m/s
The temperature difference on the outer surface of the same photovoltaic module (the area directly above the cell) should be less than 20℃. Installed capacity greater than 50kWp
The photovoltaic power station should be equipped with an infrared thermal imager to detect the temperature difference on the outer surface of photovoltaic modules.
(6) Use a DC clamp-type ammeter to measure the power connected to the same DC combiner box under the condition that the solar radiation intensity is the same.
The deviation of the input current of each PV module string should not exceed 5%.
(7) All bolts, welds, and bracket connections of the bracket should be firm and reliable, and the anti-corrosion coating on the surface should not crack and fall off
the phenomenon; otherwise, it should not be brushed in time.
2 Maintenance of combiner box
(1) The DC combiner box must not be deformed, corroded, leaked, or deposited, and the safety warning signs on the outer surface of the box should be completed.
The whole is not damaged, and the waterproof lock on the box should be flexible to open and close.
(2) The terminals in the DC combiner box should not be loose or corroded.
(3) The specifications of the high-voltage DC fuses in the DC combiner box should meet the design requirements.
(4) The insulation resistance of the positive pole to the ground and the negative bar to the bottom of the DC output bus should be more excellent than two megohms.
(5) The DC circuit breaker equipped at the DC output bus terminal should have flexible and reliable braking functions.
(6) The lightning arrester in the DC combiner box should be adequate.
3 Maintenance of DC power distribution cabinet
(1) The DC power distribution cabinet shall not be deformed, corroded, leaked, or deposited, and the safety warning signs on the outer surface of the box shall be completed.
The whole is not damaged, and the waterproof lock on the box should be flexible to open.
(2) The terminals in the DC distribution cabinet should not be loose or corroded.
(3) The insulation resistance of the positive pole to the ground and the negative bar to the bottom of the DC output bus should be more excellent than two megohms.
(4) The connection between the DC input interface of the DC power distribution cabinet and the combiner box should be stable and reliable
(5) The connection between the DC power distribution cabinet's DC output and the grid-connected host's DC input should be stable and reliable.
(6) The action of the DC power distribution cabinet's DC circuit breaker should be flexible, and the performance should be stable and reliable.
(7) The lightning arrester configured on the output side of the DC bus should be adequate.
4 Maintenance of the inverter
(1) The inverter structure and electrical connections should be kept intact, with no corrosion, dust accumulation, etc. In addition, the heat dissipation environment should be good.
There should be no significant vibration and abnormal noise when the inverter runs.
(2) The warning signs on the inverter should be intact and not damaged.
(3) The cooling fans of the modules, reactors, and transformers in the inverter should start and stop automatically according to the temperature.
There should be no significant vibration and abnormal noise when the cooling fan runs.
(4) Disconnect the circuit breaker regularly on the AC output side (grid side), and the inverter should immediately stop feeding power to the grid.
(5) The temperature of the DC bus capacitor in the inverter is too high or exceeds the service life and should be replaced in time.
5 Maintenance of AC power distribution cabinet
(1) Ensure that the metal frame of the power distribution cabinet and the bare steel is connected with galvanized bolts and the anti-loosening parts are complete.
(2) The identification devices of the power distribution cabinet indicating the number, name, or operation position of the controlled equipment should be complete, and the number should be clear and neat.
(3) The busbar joints should be tightly connected, without deformation, without blackening discharge traces, and without looseness and damage to the insulation. Tighten the connecting bolts.
Rust free.
(4) The push-pull of the handcart and the withdrawable complete set of power distribution cabinets should be flexible, and there should be no jamming and collision phenomenon.
Consistent, and the contacts are in close contact.
(5) The switches and primary contacts in the power distribution cabinet have no burning marks, and the arc extinguishing cover has no blazing black and damage. Tighten the wiring screws and clean the cabinet.
Dust inside.
(6) Take out each sub-switch cabinet from the drawer, and fasten each terminal. Check current transformers, ammeters, watt-hour meters
Installation and wiring, the handle operating mechanism should be flexible and reliable, tighten the circuit breaker inlet and outlet lines, clean the switch cabinet and the back of the power distribution cabinet.
Dust at the pinout.
(7) The heat dissipation of the heating objects of low-voltage electrical appliances should be good, the switching pressure plate should be released well, and the signal lights, buttons, lights of the signal circuit should be well
The signs, electric bells, flashlights, accident electric bells, and other actions and signals should be displayed accurately.
(8) Inspect the insulation resistance value between lines and between lines and ground between cabinets, screens, platforms, boxes, and panels, and the feeder lines must be greater than 0.5M 92,
The secondary loop must be greater than 1M.
6 Transformer Maintenance
(1) The thermometer of the transformer should be in good condition, the oil temperature should be average, the oil level of the oil conservator should correspond to the ambient temperature, and there should be no
Seepage, oil leakage. The load size, cooling conditions, and seasons of each transformer may be different, and the transformer in operation cannot be more than
The oil temperature of the layer should not exceed the allowable value. It should also be compared with the previous oil temperature based on the prior operating experience and the above conditions.
(2) The oil level of the casing should be expected, and there should be no damage, cracks, severe oil pollution, discharge marks, and other abnormal phenomena on the outside of the casing.
The oil quality should be transparent and slightly yellowish, from which the quality of the oil can be judged. In addition, the oil level should conform to the standard line of ambient temperatures, such as oil level.
If it is too low, check the transformer for oil leakage, etc. If the oil level is too high, limit the use of the cooling device to see if there is an internal failure.
(3) The sound response of the transformer is normal, and there is generally a uniform humming electromagnetic sound during regular operation. If the sound is abnormal, be careful
Check, make sound judgments, and deal with them immediately.
(4) There should be no broken strands in the transformer leads, no overheating or discoloration of the joints, or melting (discoloration) of the temperature indicator. In addition, the respirator should be in good condition.
The degree of discoloration of silica gel should not exceed 3/4.
(5) The tap position and power indication of the excitation tap changer should be expected, there should be no gas in the Buchholz relay, and the transformer should
The shell grounding and iron core grounding should be in good condition.
(6) In severe weather, special inspections should be carried out. For example, check whether the lead swings violently and whether the sag is sufficient when the wind is strong.
There should be no debris at the top cover of the transformer and the leads of the bushing. In heavy snow, the contacts of each part should not melt or have discharge immediately after the snowfalls.
Elephant. On foggy days, whether there is spark discharge in each department, etc.
7 Maintenance of cables
(1) The cable should not run under overload, and the lead pack of the line should not expand or crack.
(2) The parts of the cables entering and leaving the equipment should be sealed well, and there should be no holes with a diameter greater than 10 mm. Otherwise, they should be blocked with fire-blocking mud walls.
(3) Where the cable has too much pressure and tension on the equipment shell, the support point of the line should be intact.
(4) There should be no perforations, cracks, and significant unevenness at the mouth of the cable protection steel pipe, the inner wall should be smooth, and the metal cable pipe should not be
There should be no burrs, complex objects, and garbage if there is severe rust.
(5) The accumulations and garbage in the outdoor cable well should be cleaned up in time. If the cable sheath is damaged, it should be dealt with.
(6) When checking the open trench of indoor cables, it is necessary to prevent damage to the line and ensure that the bracket is grounded and the heat dissipation in the track is good.
(7) The stakes along the direct buried cable line should be intact, and there should be no excavation on the ground near the route to ensure that there are no piles on the floor along the way.
To ensure that the outdoor exposed ground cable protection facilities are intact, place heavy objects, building materials, and temporary facilities without discharging corrosive substances.
(8) Ensure that the cover plate of the cable trench or cable well is intact, there should be no accumulated water or debris in the channel, and ensure that the brackets in the track should be firmly
Whether there is rust or looseness, the sheath and armor of the armored cable should not be severely rusted.
(9) For multiple cables laid in parallel, the cable sheath's current distribution and temperature should be checked to prevent electrical failure due to poor contact.
The cable has burned out the connection point.
(10) Ensure that the cable terminals are well-grounded, the insulating sleeves are intact, clean, and have no traces of flashover discharge, and ensure that the cables are in the same color.
Obvious.
8 Extreme Weather Maintenance
(1) If the trip occurs when it rains, it may be that the wiring head is not tight. If such a situation arises, it must be dealt with after the rain and sunny days.
Use insulating tape to wrap the terminals and observe whether the tripping occurs. If the tripping phenomenon continues, you should contact the maintenance center or local electricity.
Station report.
(2) During thunderstorms, the air switch below the meter should be turned off to prevent damage to electrical equipment. After the thunderstorm, turn the switch on again
Close up.