What must happen in the event of a power failure regarding disconnecting means?

In the event of a power failure, it is essential that disconnecting means can be opened by hand. This requirement ensures that in an emergency situation, personnel can manually disconnect power or access equipment safely, preventing electrical hazards or further damage. The ability to operate the disconnect switch manually provides a critical safety measure, allowing for immediate action without relying on power-dependent mechanisms.

If the disconnecting means could not be operated by hand, it would pose significant risks during a power outage, where reliance on automatic systems might fail or be unavailable. Manually operable switches empower users to maintain safety and take necessary actions in response to various scenarios, including equipment downtime or maintenance, thus upholding the NEC’s safety objectives.