What is the minimum width of an entrance to enclosures for electrical installations providing access to working space over 600V nominal?

The correct answer is based on the requirements set by the National Electrical Code (NEC) regarding access to electrical installations and working spaces, particularly for systems operating over 600 volts nominal. The NEC specifies that the entrance width to enclosures must be sufficient to allow safe access and egress for personnel working on or near electrical equipment.

The minimum width of 30 inches is intended to accommodate the various tools and equipment that may need to be maneuvered into and out of the space, while also ensuring personnel can enter and exit safely. This width supports sufficient clearance for working within the space, which is critical for maintaining safety standards when handling high-voltage installations.

In contrast, smaller widths, such as 24 inches, may not provide adequate room for personnel or equipment, increasing the risk of accidents or injuries during maintenance activities. Therefore, ensuring a minimum entrance width of 30 inches aligns with the NEC's focus on safety and accessibility in electrical work environments.