What is a significant disadvantage of concentric underground cables?

A significant disadvantage of concentric underground cables is that they are subject to corrosion. This issue arises from the materials used in their construction, which can deteriorate when exposed to moisture, soil conditions, and various environmental factors over time. Corrosion can weaken the cable, lead to failures, and necessitate more frequent maintenance or replacement, which affects the overall reliability and lifespan of the electrical infrastructure.

Concentric cables are designed with layers of conductors that are tightly arranged, and while this design improves certain aspects like shielding and reduces electromagnetic interference, it does not offer substantial protection against corrosion. This is particularly important for underground installations, where cables are constantly exposed to varying moisture levels and soil chemistry.

In contrast, other issues such as higher costs, limited flexibility, and reduced insulation capacity may also present challenges with concentric cables but do not inherently affect them as directly as corrosion does. The cost is often justified by the benefits provided, flexibility refers to the physical attributes of the cable which can be managed with proper installation techniques, and insulation capacity, while crucial, is typically engineered to meet necessary standards in a balanced design. Thus, corrosion stands out as a specific and critical disadvantage in terms of long-term performance and reliability of concentric underground cables.