CableReason for aging:

1. External force damaΩ<ge. Based on operational₽∑↑ analysis in recent years, especia •≠♣lly in Shanghai Pudong w↔×here the economy is rapidly developiΩδng, a considerable n&•✔¶umber of cable failures are ca§←used by mechanical da←‌₹mage

2. Insulation is damp. This situa ≠‌✘tion is also very common, usually≠₩→≈ occurring at cable joints burieφγ​d directly or in ducts. F' ÷≥or example, if the cable joi←Ωnt is not made properly or if th™¥e joint is made under humid weather co™δ<nditions, it will cause water or stק‌eam to enter the joi≠∞&÷nt. Over time, under the action o¥©¥≠f an electric field, water ‍ branches will form, gradually damagiα>"ng the insulation strength of the cab>αΩle and causing faults

3. Chemical corrosion. Directly b♥✔π↕urying cables in areas with acidic ε"or alkaline effects often causes corr™¶osion of the cable's armor, lead shea>&₽¥th, or outer protective layer. The γ★&protective layer may fail due to lo §ng-term chemical or electrφ¶♥olytic corrosion, resulting in reduced £ ≥πinsulation and cable failure. ÷ Chemical: The corrosion of the unit's c∑✔ables is quite severe

4. Long term overload <‌operation. Overload operation,•""✔ due to the thermal e∞>±ffect of current, inevitably cau♠¶ses the conductor to he₹φ÷→at up when the load current passes t"≤★hrough the cable. At the same time >, the skin effect of₽∞ charges, eddy current loss of sσ✘teel armor, and insulation≠ ♥ medium loss also gene←♥rate additional heat, therα‌γeby increasing the temperatur↔α"e of the cable

5. Cable joint malfunction. Ca™✔ble joints are the weakest <₽ link in cable lines, and cabl✘¥e joint failures oft≈♦en occur due to direct human∞<☆♠ error (poor construction). ≤γ‍∞During the process of making cable jo♠ α¥ints, if there are reas→Ωons such as loose crimping or→₹ insufficient heating, the ins≤¥ulation of the cable head♥∑​ may decrease, leading to accidents

6. Environment and temperature→ . The external environment and heaφεt sources in which cables are loca£∏£αted can also cause high cable tem★‍₹∞peratures, insulation break₽∞₽down, and even explosions a•×nd fires