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The cause of damage to the lead sheath of cables are
Crystallization of lead through vibration
Chemical reaction with impurities present in a soil
Mechanical injury
Any of above
Any of above
The lead sheath in underground cables serves as a protective layer against moisture ingress and mechanical damage; however, it is susceptible to various degradation processes. These include chemical corrosion, physical stresses, and material fatigue due to external environmental factors.
The lead sheath in underground cables serves as a protective layer against moisture ingress and mechanical damage; however, it is susceptible to various degradation processes. These include chemical corrosion, physical stresses, and material fatigue due to external environmental factors.
S=AFтАЛ тАФ mechanical stress where F is force and A is cross-sectional area, highlighting how sheath fatigue occurs
Lead is used because it is impervious to moisture and highly flexible for installation.
The lead sheath is non-magnetic and acts as an earth return path in some configurations.
Corrosion protection is often supplemented by serving or bedding (bituminous compounds).
Fatigue cracking is often called 'crystallization' in trade terminology.
Moisture-proof barrier
Corrosion resistance in specific neutral environments
Effective earth continuity
Heavy weight
Susceptibility to vibration-induced cracking
High cost compared to modern synthetic sheaths
High-voltage underground transmission
Submarine power cables
Industrial environments with chemical presence
Modern cables often substitute lead with aluminum or synthetic sheathing (e.g., XLPE/PVC layers) due to lead's weight and fatigue issues.
Option A refers to long-term fatigue under cyclic stress.
Option B relates to electrochemical potential difference between the soil and the lead sheath.
D is correct тАФ All listed factors contribute to the deterioration of the lead sheath, ultimately leading to moisture ingress and potential cable insulation failure.
Always remember that 'Any of above' in power system fault analysis often includes all environmental and physical stressors; think about the cable as a component existing in a dynamic physical environment.