Under what conditions are non-shielded cables permitted for circuits over 5,000 volts?

Non-shielded cables can be permitted for circuits over 5,000 volts under no restrictive conditions because such configurations may be permitted in specific contexts dictated by regulations or industry standards that prioritize safety and functionality. This option implies that non-shielded cables are recognized as acceptable under general circumstances, as long as they adhere to overarching guidelines regarding installation and use, thereby allowing flexibility depending on the situation.

The significance of acknowledging the absence of restrictive conditions means that for non-shielded cables, certain installations might not necessitate additional protective measures under established electrical standards. These standards may include considerations for installation in controlled environments or where proper electrical insulation and safety protocols are in place, enabling certain non-shielded cables to function effectively in high-voltage applications without undue risk.

In contrast, the other options hint at specific circumstances that would limit the use of non-shielded cables or might require additional oversight, which is not aligned with the notion that they can be used in a broader, more general context without restrictions.