光伏电站要户外运行25年，线束是系统里最先被环境"腐蚀"的部件之一。组件本身按25年设计，而劣质连接线束5-8年就可能出现绝缘老化、接头氧化，成为电站热斑隐患。
PV plants must run 25 years outdoors, and harnesses are among the first parts the environment attacks. Poor connections age in 5-8 years and become hot-spot hazards.
1. 抗紫外：交联材质是分水岭1. UV: cross-linked jackets are the dividing line
普通PVC在紫外线照射下增塑剂挥发、绝缘开裂。户外光伏线束应选用交联聚烯烃（XLPO）或辐照交联材质（如PV1-F类光伏专用线），并通过UV老化测试。
Ordinary PVC cracks under UV. Use cross-linked polyolefin (PV1-F class) wire with UV aging test data.
2. 温差循环：-40℃到+90℃2. Thermal cycling: -40°C to +90°C
西北电站昼夜温差可达60℃以上，反复热胀冷缩会让压接点松弛。光伏连接建议采用专用MC4类连接器（对插自锁、密封圈防水），压接后做温度循环验证。
Thermal swings of 60°C+ loosen crimps. Use MC4-class locking sealed connectors and verify with thermal cycling.
3. 防水与盐雾3. Water and salt spray
户外接线部位防护等级要求IP67以上；沿海滩涂电站还要耐盐雾（连接器触点镀层与壳体材质对应加严）。汇流箱内线束建议做滴水弯走线，防积水倒灌。
Require IP67+ at outdoor joints; coastal plants need salt-spray-rated plating and housings, and drip loops inside combiner boxes.
4. 载流与直流特殊性4. DC-specific current sizing
光伏直流系统按组串电流×1.25以上系数选线径；直流拉弧风险高于交流，任何接头缺陷都可能发展成持续电弧，这是"全检+优质连接器"不能省的根本原因。
Size DC runs at 1.25x string current; DC arcs sustain more easily than AC, so 100% inspection and quality connectors are non-negotiable.