In outdoor strong light, high temperature, and high UV environments in Africa, the UV resistance level of the PC lighting electrical Ready Board Box shell should reach F2 level (super strong UV resistance), and meet UV400 protection, QUV aging ≥ 5000 hours, color difference Δ E ＜ 2.0, and strength retention rate ≥ 95%, in order to resist direct sunlight for a long time and prevent yellowing/brittle cracking. 1、 Grade and standard basis - Basic grade: unmodified PC only has Grade 3 weather resistance, cracks in 1-2 years outdoors in Africa, and cannot be used. -Minimum requirement: F1 grade (UL 746C), QUV 3000 hours, strength retention rate ≥ 90%, suitable for weak UV areas. -African mandatory standards: F2 level, QUV above 5000 hours, UVA-340 irradiation, UV400 full band protection (blocking 99% UVA/UVB). -Key indicators: color difference Δ E<2.0 after aging, impact strength retention rate ≥ 95%, no cracks/powdering. -Compliance standards: Complies with IEC 62208 and GB/T 16422.3, with an outdoor lifespan of ≥ 10 years. 2、 Material scheme (anti-aging/cracking) 1 Modified PC (preferred): Add HALS+UV absorbers such as Chi Mei PC-110U, Mitsubishi UV5000, F2 grade, temperature resistance -40 ℃ to 120 ℃. two Surface UV coating: double-sided hardening+UV resistant layer, QUV 5000 hour yellowing index Δ Y ＜ 10. three Structural protection: The box is equipped with sun protection eaves to avoid direct sunlight; The sealing strip is made of UV resistant silicone rubber to prevent aging and water leakage. 3、 Why is it necessary for F2 level African ultraviolet intensity to be 2-3 times that of temperate zone, with ordinary PC yellowing in 6-12 months and brittle fracture in 2-3 years; F2 grade modified PC can be stable for more than 10 years, ensuring insulation and structural safety.