Which of the following is a safety requirement for working on cables greater than 600 volts?

Working on cables greater than 600 volts requires that they must be deenergized to ensure safety. This is a critical safety protocol in electrical work because energized cables can pose severe risks, including electrical shock, burns, and fatal accidents. Properly deenergizing cables allows workers to perform maintenance or repairs without the immediate threat of electrocution.

Safety standards, such as those set by organizations like the Occupational Safety and Health Administration (OSHA), emphasize the importance of deenergizing circuits before workers begin any activities. This procedure not only involves turning off the power but typically includes locking and tagging out the equipment to prevent unintentional re-energization while work is in progress.

In contrast, marking cables with flags, exposing them to air, or relying on insulation do not guarantee safety from electrical hazards. While marking and insulation can be part of an overall safety strategy, they are not sufficient by themselves to protect workers from the dangers associated with high voltage. These practices contribute to awareness and hazard recognition but do not eliminate the risks as effectively as ensuring the cables are deenergized.