It is common for space for electrical panels and equipment to be dedicated in a commercial building. Read about the requirements:
It is common to reserve space for electrical panels and appliances in a commercial building. A commercial building will often have a main room for major electrical services and also, on other floors, smaller electrical rooms.
A requirement of the National Electrical Code requires is ‘‘clear space” which is to provide easy access to the overcurrent equipment and provide adequate space for repair and review, referenced as working space around the panelboard. Working space can differ, as shown in the diagram below, based on the voltage of the electrical equipment and related structures and walls.
Dedicated work room needs to be provided before and right above the panelboard. The working space width in front of the device must be at least 30″ or the equipment width, whichever of the two is greater. The working space also stretches vertically from the floor or grade to a minimum height of 6-1/2′ or equipment height, whichever is greater. Such specifications are given for in National Electrical Code article 110.26 and Table 110.26(A)(1).
Local codes also may determine acceptable dimensions of work spaces. For example, the City of Austin requires the vertical extension of the working space from the floor to the structure beyond the NEC’s 6 -1/2″requirement.
It is not common for a space to be dedicated for installing an electrical panel in residential facilities. Therefore panelboards are often installed in single-family homes in basements or garages. The panels are often mounted in dormitories or halls of apartments or condos. Article 240.24 describes the positions where panel boards may not be placed, and therefore by default, overcurrent equipment. The code states that panel boards may not be placed in the vicinity of readily ignitable content (such as wardrobes), toilets, over stairs, in plumbing walls, or near to sinks or plumbing fittings. Furthermore, the code is diligent to state that the panel boards be placed in a readily accessible spot, implying that the highest circuit breaker’s top cannot be over 6’7″AFF or from the workstation. There are also local codes limitations on the locations of panelboards.
Installation of panelboards may be outdoors or indoors. Panelboards have to be built using the correct NEMA classification for the setting they are being used in. Indoor panelboards usually have the NEMA 1 classification whereas outdoor panelboards generally have the NEMA 3R ranking.