The National Electrical Code (NEC) published the recognized regulations on clearance requirements for 480-volt electrical panels. These requirements are necessary to keep maintenance personnel safe while working on high-voltage panels. The clearance requirements also meet all government safety standards such as those set by the Occupational Safety and Health Administration (OSHA).
Overhead Clearance
Electrical wires running to the 480-volt electrical panel must be a minimum of 12 feet above the ground if the panel is located outside. This 12-foot minimum requirement is also required over pavement and a minimum of 22 feet is required over roads.
Front Clearance
The NEC requires that there be a minimum of three feet of clearance in front of a 480-volt electrical panel. This clearance is measured for the live electrical parts or front of the electrical panel. This clearance is different if the 480-volt electrical panel faces a wall where other electrical panels are located. A minimum of 30 inches of width is also required in front of the electrical panel.
Front Clearance When Facing Other Electrical Panels
The NEC front clearance requirement is different when the 480-volt electrical panel faces another electrical panel or grounded wall. A minimum of 3 feet of clearance in front of the electrical panel is required in this instance. The higher the voltage, the greater the distance from panel to panel.
Headroom
A minimum of 6 feet of headroom is required when working on a 480-volt electrical panel. This 6-foot clearance is measured from the floor or work platform to any obstruction located overhead. This requirement prevents workers from touching any object that can ground the worker producing a shock or burn.
