Which of the following is NOT a permitted physical characteristic of grounding electrode conductors?

Grounding electrode conductors are essential for ensuring safety in electrical systems by providing a low-resistance path to ground. The characteristics of these conductors are defined by electrical codes to ensure their effectiveness and reliability.

The statement that they can be bare, insulated, or covered highlights the flexibility allowed in their construction. Bare conductors are commonly used because they can directly connect to grounding electrodes, providing excellent conductivity. Insulated conductors, on the other hand, may be used in scenarios where additional protection from environmental elements or touch is necessary. Covered conductors, similarly, offer some protection while maintaining conductivity.

Unshielded conductors, while a term that may refer to a lack of covering or protection, are not included in the permitted physical characteristics because the term can imply a lack of any protection mechanism, which does not align well with safety standards. This can potentially expose the conductor to physical damage or electrical hazards, making it less desirable for grounding applications. Therefore, the characteristic of being unshielded does not meet the requirements typically set for grounding electrode conductors.