Final answer:
The dimensions of working space needed for access to live parts operating at 300V with live parts exposed on both sides is 3 feet according to the National Electrical Code.
Step-by-step explanation:
The dimensions of working space for access to live parts operating at 300V, nominal to ground, where there are exposed live parts on both sides of the workspace is 3 feet. Electrical safety standards specify the minimum amount of space required to ensure that workers have sufficient room to avoid contact with energized parts. The standard for 300V, as defined by the National Electrical Code (NEC), is a minimum clearance of 3 feet in front of the electrical equipment for safe operation and maintenance.