Interrupting Rating, Mounting and Cooling of Equipment

If equipment is designed to break current, it must have an interrupting rating at a system voltage adequate for the current that must be interrupted.

Electrical equipment must also be firmly secured to the surface to which it is mounted. Workers cannot use wooden plugs driven into holes in masonry, plaster, or other materials to mount electrical equipment.

Some electrical equipment is cooled by air circulation. Electrical equipment that is cooled in this way must allow room for air flow over these surfaces. It cannot be installed in a way that walls and adjacent equipment could block this air flow. Floor-mounted equipment that is cooled in this way must be installed so that there is adequate top and adjacent surface clearance to allow rising warm air to dissipate.

Electrical equipment that has ventilating openings must be installed so that walls and other obstructions do not prevent the circulation of air through the equipment.

To learn more about Construction Electrical Safety visit our Construction Electrical Safety Online Training web page.