Effective Storage Period And Overdue Re-inspection Of Cable Terminals
cable lugs is composed of two parts of different materials: plastic insulation parts and hardware parts with different coatings. The storage period of plastic and metal is different. The storage period of a complete product should be based on the fastest aging parts. Under normal circumstances, the life of insulation parts is 3 years, but due to different storage environments, the difference is very large.
In the early days, the US military standard stipulated that semiconductor discrete devices that were "stocked" for more than 12 months need to be re-inspected when delivered, so it can be considered that the effective storage period of semiconductor discrete devices is 12 months. The version released later stipulates that semiconductor discrete devices that are more than 24 months old need to be re-inspected when delivered; the new version released later stipulates that semiconductor discrete devices that are "stocked" for more than 36 months need to be re-inspected when delivered.
3. Overdue re-inspection of wire lugs
electrical lugs in stock for more than 3 years should be re-inspected before installation. The re-inspection test includes: electrical characteristics test, visual inspection and destructive physical analysis (DPA). Use a 3~10x magnifying glass or microscope to inspect the appearance of terminal lugs. copper lugs terminal breakage or shell shedding is a fatal defect; terminal rust or surface damage is a serious defect; surface coating shedding, bubbling or unclear markings but not affecting use is a minor defect. Aluminum Cable Lug with these three defects is unqualified. Electrical characteristic test, for Compression Cable Lug that has been tested for electrical characteristics before entering the warehouse, the same parameters should be tested according to the method of warehouse test. For the terminal blocks that have not been tested for electrical characteristics when entering the warehouse, the functions and main parameters should be tested according to the corresponding detailed specifications or product manuals of the terminal blocks.
In short, the "shelf life" of the terminal blocks is very long, but the effective storage period is not long. Under good temperature and humidity control, the life span can reach 3 years. If the environment is harsh, the terminal life span is only one and a half years or even shorter. The acidic and alkaline environment is very harmful to the terminal, so it is necessary to conduct product inspections regularly and replace the terminal connector immediately if aging is found.
