For “large equipment”, the egress door would be NEC® compliant if it only opened far enough to provide a 24-inch egress width as required in Section 110.26(C)(2). In the 2023 NEC®, personnel doors covered in Section 110.26(C)(3) must now be able to open at least 90° in the direction of egress.
Open equipment doors must not impede access to and egress from the required working space. If one or more equipment doors are open and access to and egress from the working space is reduced to less than 24 inches wide and 6.5 feet high, the access is considered impeded.
Whether one or two entrances are required, those entrances are required to be a minimum of 24 inches wide and 78 inches high. However, it is critical to ensure that entrances, whether it is a single entrance or two entrances, are sized to permit the equipment to be moved in and out of the room.
The rule in 110.26(C)(3) that requires doors to swing out only applies when the electrical equipment in the room is rated at 1200 amps or more. 110.33(A)(3) requires swing out doors for electrical rooms that contain equipment operating over 600 volts.
Remember, not every electrical room requires doors with panic hardware – it depends on the voltage, amperage, and other electrical equipment specifications. Check the adopted code in your project's jurisdiction for prescriptive requirements.
For all doors that provide means of egress for rooms and spaces of assembly and educational (Group A and E) occupancies with an occupant load of 50 or more, if latching (or locking) hardware is installed, it must be panic hardware or fire exit hardware. This would include large assembly spaces in mixed-use buildings.
Two exit access doorways are required in boiler, incinerator and furnace rooms where the area is over 500 square feet (46 m2) and any fuel-fired equipment exceeds 400,000 British thermal units (Btu) (422 000 KJ) input capacity.
For equipment rated 1200 amperes or more and over 1.8 m (6 ft) wide that contains overcurrent devices, switching devices, or control devices, there shall be one entrance to and egress from the required working space not less than 610 mm (24 in.) wide and 2.0 m (6 ½ ft) high at each end of the working space.
This article covers general requirements for the examination and approval, installation and use, access to and spaces about electrical conductors and equipment; enclosures intended for personnel entry; and tunnel installations.
Electrical rooms in and of themselves do not require fire ratings because they are labeled “electrical room” but may need to have rated partitions depending on the type of equipment contained therein or the ratings of the adjacent spaces.
NEC Section 210.52(a)(1) (aka 6'-12' rule): Receptacles shall be installed such that no point measured horizontally along the floor line of any wall space is more than 6' from a receptacle outlet..
Note that all panel doors and access doors must be able to open a minimum of 90 degrees. Side clearance: There should be a minimum of 30 inches of clearance from the sides of all electrical equipment, but in no case less than the width of the equipment itself. This is referred to as the side-to-side working space.
The 2023 version of the NEC moved this language to the main section of 110.26 and states, “Open equipment doors shall not impede access to and egress from the working space. Access or egress is impeded if one or more simultaneous opened equipment doors restrict working space access to be less than 610 mm (24 in.)
Fire doors must be used in walls which form the compartmentation of the premises – specific areas within the building that are constructed to be fire-resistant. These may be individual rooms, but could also contain multiple rooms or might be vertical risers and lift shafts.
Enforced in all 50 states, NFPA 70, National Electrical Code (NEC) is the benchmark for safe electrical design, installation, and inspection to protect people and property from electrical hazards.
Basically, the NEC 120% rule allows solar PV equipment to be installed in electrical boxes up to 120% of the installed electrical equipment safety label rating.
Article 525 addresses the installation of portable wiring and equipment for temporary attractions, such as carnivals, circuses, and fairs. Article 525 is intended to apply to all wiring in or on portable structures, whereas Articles 518, 520, and 522 apply to permanent structures.
NEC 110.14(A) has a blanket statement requiring that terminals for more than one conductor shall be so identified. This would mean that the terminal (or terminal bar) would have to be identified to accept more than one conductor.
If the equipment is more than 6 feet wide or 6 feet deep, there must be a door at each end of the working space, providing entrance to and egress from the required working space.
Rooms containing electrical equipment shall be provided with a second exit or exit access doorways as required by NFPA 70 Article 110 where all of the following apply: The electrical equipment is rated at 1,200 amperes or more. The electrical equipment is over 6 feet (1829 mm) wide.
Working space starts at the front of the panel. Under NEC that means nothing is to intrude into that space when the door is open.
Machinery rooms larger than 1,000 square feet (93 m2) shall have not less than two exits or exit access doorways. Where two exit access doorways are required, one such doorway is permitted to be served by a fixed ladder or an alternating tread device.
Exit and exit access doors serving electrical rooms and working spaces shall swing in the direction of egress travel and shall be equipped with panic hardware or fire exit hardware where such rooms or working spaces contain one or more of the following: Equipment operating at more than 600 volts, nominal.
Electrical rooms that are located in covered or open malls and that open into exit passageways require a 1-hour fire rating for walls and doors that are common to the electrical room and the exit passageway.