Proper selection of screws for solar energy equipment requires comprehensive consideration of multiple factors to ensure the stability, safety, and durability of the equipment. Here are the specific selection guidelines:Consider Environmental Factors
Climatic Conditions: Choose screws based on the climatic conditions of the installation site. In coastal areas or high-humidity environments, due to corrosion from salt spray and moisture, screws with strong corrosion resistance should be selected, such as 316 stainless steel screws, to prevent rust and damage. In regions with high temperatures and intense ultraviolet (UV) radiation, screws must have good high-temperature resistance and anti-aging properties to avoid performance degradation due to high temperatures or surface embrittlement caused by UV exposure.
Sand and Wind Conditions: In sandy and windy areas, screws may suffer wear from sand particles. In such cases, screws with high surface hardness and good wear resistance should be chosen, such as specially treated stainless steel screws, to extend their service life.
Determine Load Requirements
Static Load: Calculate the weight borne by various components of the solar equipment under normal conditions, including the weight of photovoltaic panels, brackets, etc., and select screws capable of withstanding the corresponding static load. For example, in large-scale solar photovoltaic power plants, where photovoltaic panels and brackets are heavier, high-strength screws such as 8.8 or 10.9 grade stainless steel screws are required to ensure secure connections.
Dynamic Load: Consider dynamic loads that the solar equipment may encounter during operation, such as wind force and seismic force. In areas with strong winds, screws must withstand vibration and impact forces from strong winds. Screws with anti-loosening designs, such as those with lock washers or self-locking threads, can be selected to prevent loosening.
Select Appropriate Materials
Stainless Steel: 304 stainless steel screws offer good corrosion resistance and comprehensive performance, making them suitable for solar equipment in most general environments. 316 stainless steel screws have stronger corrosion resistance, especially suitable for highly corrosive environments such as coastal areas and chemical industries.
Aluminum Alloy: Aluminum alloy screws are lightweight and suitable for solar equipment with weight requirements, such as small portable solar devices. However, aluminum alloy screws have relatively low strength, so selection should be evaluated based on actual load conditions.
Titanium Alloy: Titanium alloy screws have excellent performance, including high strength, corrosion resistance, and low density, but they are costly. They are generally used in special solar projects with extremely high performance requirements.
Match Specifications and Sizes
Thread Specifications: Select appropriate thread specifications based on the thickness of the connected components and connection requirements. Common specifications include M4, M5, M6, M8, etc. Typically, M6 or M8 screws are commonly used for connecting photovoltaic panels to brackets, while M4 or M5 screws may be used for fixing small components.
Head Shape: Choose the screw head shape based on installation space and tool accessibility. Hexagon socket head screws facilitate applying large torque, suitable for parts requiring high clamping force; countersunk head screws can keep the surface flat without affecting the installation of other components; hexagon head screws are widely used as they can be operated with ordinary wrenches.
Screw Length: Ensure the screw length is appropriate to guarantee a secure connection without being too long to hinder installation. The length should be determined based on the total thickness of the connected components. Generally, the screw should protrude with a certain thread length after being screwed in, but not excessively.
Pay Attention to Anti-Loosening Designs
Lock Washers: Using lock washers is a common anti-loosening method, such as spring washers and lock washers. Spring washers prevent loosening through friction generated by elastic deformation; lock washers increase friction between the screw and connected components through special structural designs.
Self-Locking Threads: Select screws with self-locking threads, such as nylon-insert lock nuts and all-metal self-locking nuts. These screws have special structures in the thread section, which can effectively prevent loosening.
Consider Brand and Quality Certification
Brand Reputation: Choose screws from well-known brands, which usually have better guarantees in production processes and quality control, ensuring more reliable product performance and quality.
Quality Certification: Ensure the screws have relevant quality certifications, such as ISO certification and RoHS certification. These certifications can prove that the screws meet certain quality standards and environmental requirements.
By comprehensively considering the above factors, you can correctly select screws suitable for solar energy equipment, ensuring the normal operation and long-term stability of the solar equipment.
