This article is about NEC Article 110.13 Mounting and Cooling of Equipment.
Mounting and Cooling of Equipment (NEC 110.13)
Electrical equipment must be firmly attached to the surface where it is installed. Secure fastening methods should be used, such as screws or bolts, rather than wooden plugs driven into holes in masonry, concrete, plaster, or similar materials.
Electrical equipment that relies on natural air circulation and convection for cooling exposed surfaces should be installed in a way that does not obstruct or impede room airflow. If the equipment is designed to be mounted on the floor, space should be left between the top surface and any adjacent surfaces to allow warm air to escape.
Ventilated electrical equipment should be installed in such a way that walls or other obstructions do not impede the free flow of air around it.
Proper placement of equipment that requires ventilation is enforced by the requirements of 110.3(B) in addition to 110.13. Ventilating openings are provided in equipment to allow the circulation of room air around internal components, as blocking these openings can lead to dangerous overheating. Motor locations must follow the ventilation requirements of 430.14(A) and 430.16, while transformer locations must follow the ventilation requirements of 450.9 and 450.45. Furthermore, panelboards, transformers, and other equipment must not have their enclosure surfaces normally exposed to room air covered or tightly enclosed, as this can adversely affect the equipment.
To ensure safe operation and avoid dangerous overheating, panelboards, transformers, and other types of equipment must be positioned so that ventilation openings are not blocked. These openings are designed to enable the circulation of room air around the internal components of the equipment. For instance, a ventilated busway must be located in such a way that walls or other objects do not impede the flow of air and impede the cooling process via convection.