The minimum height of the working space in a commercial installation is _________.

In a commercial installation, the minimum height of the working space is crucial for ensuring safety and comfort for personnel working with electrical equipment. The correct answer is that the minimum working height is 6 feet. This dimension is stipulated in electrical codes to allow adequate room for maintenance and safe operation of equipment.

By specifying a minimum height of 6 feet, regulations ensure that workers have sufficient vertical clearance to perform tasks without the risk of injury from bending or working in cramped positions. The 6-foot requirement aligns with industry standards supporting safe access to electrical panels, switchboards, and related equipment, promoting an environment where personnel can operate efficiently and securely.

Higher options may pertain to specific situations or certain types of installations but do not represent the general minimum height requirement for working spaces in most commercial settings. Thus, this standard allows for both practical working conditions and compliance with safety regulations.