July 11, 2011

Electrical | Distances for Access and Clearance

Electrical workers need to be able to move quickly away from a hazardous situation. They also need to be protected from grounded surfaces. That is why OSHA requires you to provide and maintain sufficient access and working space about electrical equipment for safe operation and maintenance of the equipment. There are two aspects to the OSHA requirements:
  • Sufficient access.
  • Space for working on live electrical equipment.
OSHA does not define what "sufficient access" means but they do say that you can't use the space for storage. Other than that, for equipment that is "buttoned up" and does not have exposed live components, there are no other requirements. You may want to mark the area on the floor that is required to be kept clear when employees are working on the equipment.
If equipment is normally closed but is open for inspection or servicing while energized, you must guard the area.
The OSHA regulations are very specific as to the space required for working on electrical equipment. Those requirements are in the electrical standard at §1910.303(g) for equipment 600 volts or less and .303(h) for equipment over 600 volts. Following is an overview of the working space requirements.
Equipment 600 volts or less
  • The depth of the working space in the direction of access to live parts is determined by the voltages involved and the relationship to other equipment and surfaces in the area. Table S-1 of §1910.303(g) determines the actual working space requirement. Distances are always measured from the live parts.
  • The width of the working space must be the width of the equipment or 30 inches whichever is greater. The working space must allow at least a 90° opening of doors and hinged panels.
  • The height of the working space must be clear and extend from the floor to six feet, six inches (Note: For installations built before August 13, 2007, the height must be 6 feet, 3 inches.)
  • At least one door must be provided to give access to the working space about electrical equipment if it is located in a room. A second entrance is required for equipment rated 1200 amperes under certain conditions.
Equipment exceeding 600 volts must comply with all of the applicable requirements for 600 volt and less installations and with additional requirements. Here is an overview of those additional requirements:
Equipment over 600 volts
  • The depth of the working space is determined by the voltages involved. The requirements in Table S-2 range from three to 12 feet minimum clear work space.
  • The width of the space must not be less than three feet wide.
  • The height of the working space must not be less than six feet, six inches.
  • The workspace must be adequate to permit at least a 90° door opening.