How to do a good job of crack control after the components leave the factory?

A few years ago, cell cracks, hot spots, and PID effects were three important factors affecting the performance of crystalline silicon photovoltaic modules.

In recent years, with the rapid progress of technology, equipment, and materials, these problems have been greatly improved, especially in the production process of first-line enterprises, 100% effective identification and strict inspection of hidden cracks and hot spot defects can be achieved. Passed 192 hours PID test under control and double 85 conditions.

Although in the production process, thanks to equipment stability, parameter temperature adjustment, additional battery preheating link, multi-channel quality inspection and material improvement, the steps of welding, lamination and framing basically overcome the problem of hidden cracks . However, improper handling, installation, construction, operation and maintenance, and random stacking of exposed components on site will still cause cracks or even damage to components.

In recent years, with the rapid development of the distributed market, large and small installation and construction teams with mixed quality or without systematic training, after the components leave the factory and before and after installation, the components are hidden due to improper external forces during storage, transportation and installation. The crack problem is increasingly becoming a new problem.

The editor summarized for everyone, the factors that lead to hidden cracks may appear in the following links:

1. During the handling process, the packing box is tilted, causing the components to squeeze each other, causing uneven force and cracks.

2. During the transportation process, violent loading and unloading by the forklift driver, large bumps in the transportation vehicle, and the removal and replacement of pallets by the second time will also cause cracks in the components.

3. During the installation, cleaning and maintenance process of the workers, irregular operations may cause hidden cracks in the components, such as single-person back components, head-top components, stepping on the components during the component installation process, and operation and maintenance personnel standing on the components to clean up the dust accumulation Wrong operations such as these will lead to cracks in the components.

4. When placing components, place or rely on uneven surfaces.

5. The components were not installed immediately after unpacking, and the components were randomly scattered and randomly stacked on the project site.

So how to avoid these problems?

We all know that a professional EPC company will strictly control the transportation, unloading, secondary handling, on-site storage and installation of components. Today we will take a look at how to control the hidden cracks of components after leaving the factory from three aspects: component placement, secondary handling, and installation.

1. Component placement

1. The stacking site of the whole box of modules should be flat and open to facilitate the transportation operation and avoid cracks or damage of the modules caused by the ground skew.

2. The stacking height of the whole box shall not exceed the height of two boxes. Pay attention to the orderly top and bottom of the pallet, and avoid hanging the corners of the pallet.

3. After placing it in place, try to avoid carrying or moving it before it arrives for construction. Repeated movement increases the risk of cracking of components.

4. After the components are arranged neatly, they should be covered with colored striped cloth and other materials to avoid obvious damage or cracks caused by tilting or rollover of the components after the site is continuously washed by rain.

5. When temporarily placed flat, it must be placed neatly on a pallet or on a flat ground. The first and last module glass faces upward, and the back of the middle module faces upward. No more than 18 flat modules are allowed.

6. When temporarily leaning against columns or other objects, they also need to be placed neatly. The supporting objects must be flat and not protruding, and should not exceed 10 pieces.

7. Temporary placement of components should be completed in one day, and the remaining components should be placed neatly or protected to avoid collapse when unattended.

2. Secondary handling of components

1. After the components are unpacked, when each component is transported to the installation location, two people are required to carry a component, avoiding one person to carry one or more components, reducing the risk of components being dropped, and reducing the risk of component cracks or damage caused by bumps or vibrations.

2. Pay attention to the environment around you during the handling process, and avoid bumping yourself and the components into other objects, causing the components to crack or explode.

3. After the components arrive at the installation location, lean against the installed support beams to avoid laying on the ground.

4. Forklifts should be used for single-box transfer of components, and cranes should be used for surface projects. In order to avoid damage during the transfer of components, non-conventional mechanical transfers (excavators, loaders, etc.) should be prohibited.

5. When the module is on the roof, it is necessary to protect the surroundings of the module to avoid accidental collision between the module and the wall or corner, which may cause cracks or obvious scars inside the module.

3. Installation of components

1. When the components are installed, they should be installed from top to bottom. When installing components, avoid temporary fixation between the upper and lower components with materials such as bricks and wooden plugs, and use at least two upper bolts for temporary fixation.

2. During the module installation process, try to avoid the installation workers directly operating on the module, stepping, sitting, kneeling, knocking, squeezing, hitting the module, which may cause partial cracking of the internal battery sheet.

3. The bolts of the installation components must be fastened firmly, and the spring washers must be fastened to be flat.

4. When using a pressing block to fix the component, the horizontal plane of the pressing block should be in firm contact with the frame of the component to avoid any angle.

For the first-line photovoltaic enterprises, our suggestion is to provide more detailed and professional on-site component crack prevention guidebooks, videos and other materials to EPCs, installers and agents, and even provide professional training courses. This is also the responsibility of front-line enterprises.

Because unlike the experienced EPC of large-scale ground power station projects, the professional knowledge and experience of distributed project owners, installers, and agents will be relatively weak, and first-line photovoltaic companies need to provide more detailed and thoughtful guidance services.