The Life Safety Code (NFPA 101) is a model code produced by the National Fire Protection Association (NFPA). It is adopted by various governing bodies to regulate components of means of egress, active, and passive life safety systems. Although the Life Safety Code is a major source of requisites, there are additional life safety concerns associated with electrical equipment. This document highlights such requirements as many designers are not familiar with the intricacies of technical standards such as the National Electric Code (NFPA 70). Conversely, users of technical standards are generally not concerned with fire and life safety, as it pertains to the layout and construction of buildings.
Number of Means of Egress
NFPA 101 dictates the required number of means of egress from any balcony, mezzanine, story, or portion thereof. Generally, the number of means of egress shall be not less than two, while observing single egress allowances for common path distances. NFPA allows electric rooms to be served by one means of egress, provided that the exit can be reached within the distance permitted as a common path of travel. However, per Section 110.26(C)(2) in NFPA 70-2014, there shall be two means of egress (one at each end of the electric room) from any space containing equipment rated 1,200 amperes or more and measuring over six feet wide, if the equipment contains overcurrent devices, switching devices, or control devices. This is typical of service equipment in box stores and factories.
Panic and Fire Exit Hardware
NFPA 101 dictates when to install panic or fire exit hardware (panic hardware listed for fire doors). According to NFPA 101, panic or fire exit hardware is required In Assembly, Education, and Day-Care Occupancies when an occupant load exceeds 99 people. Note, this requirement differs from the International Building Code (IBC), which requires the installation of panic or fire exit hardware in Use Groups H or A and E when either has an occupant load in excess of 49 people. NFPA 70 also requires panic hardware in some electric rooms. Per Section 110.26(C)(3) in NFPA 70-2014, if a space contains equipment rated 800 amperes or more and if the equipment contains overcurrent devices, switching devices, or control devices, the space shall be equipped with panic hardware. The room’s door(s) must also open in the direction of travel. In an emergency (arc flash, etc.), an occupant’s hands may become damaged and thus the installation of panic hardware is useful.
Fire-Resistance Rated Construction
NFPA 101 requires fire-resistance rated construction for various situations. Such construction is most notably due to construction type, hazardous materials, occupancy location, shaft, and exit enclosure requirements. Per NFPA 70, the requisite of fire-resistance rated construction is also dependent on the presence of transformers. According to Section 450.21 in NFPA 70-2014, individual dry-type transformers greater than 112.5 kVA shall be installed in a transformer room of 1-hour fire-resistance rated construction. This requires the room to be equipped with a 1-hour fire door-frame assembly. Furthermore, joints and penetrants must be firestopped in accordance with UL listed assemblies.
Section 9.1.3.1 in NFPA 101-2015 requires emergency generators and standby power systems to be installed, tested, and maintained in accordance with the Standard for Emergency and Standby Power Systems (NFPA 110). According to NFPA 110, a Level 1 emergency power system (EPS) shall be installed where the failure of equipment to perform could result in loss of life or severe injury. Furthermore, according to Section 7.2.1 in NFPA 110-2013, a Level 1 EPS must be enclosed in 2-hour fire-resistance rated construction. Also, no other equipment, except those that serve the space, shall be permitted in the EPS room.
NFPA 101 requires sprinkler systems to be installed in accordance with the Standard for the Installation of Sprinkler Systems (NFPA 13), the Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes (NFPA 13D), or the Standard for the Installation of Sprinkler Systems in Low-Rise Residential Occupancies (NFPA 13R). According to commentary in NFPA 13-2013, sprinkler systems have been successfully installed in rooms containing electrical equipment for over 100 years with no documented instances of a problem. However, some people are still leery of installing sprinklers in electrical rooms. Thus, Section 8.15.11.3 in NFPA 13-2013 allows sprinklers to be omitted from an electrical room if all the following conditions are met: (1) the room is dedicated to electrical equipment, (2) only dry-type equipment is used, (3) equipment is installed in 2-hour fire-resistance rated construction, and (4) no combustible storage is permitted. Omitting sprinklers from electrical rooms is likely costlier and requires more effort from the designer(s). Furthermore, the building owner is responsible for policing the electric room to reduce the likelihood of the space being used for storage.
Conclusion
Although the Life Safety Code is a major source of requisites, there are additional life safety concerns associated with electrical equipment. Thus, designers must have a general understanding of a building’s electrical system to properly protect occupants. As demonstrated, designers must be aware that life safety requirements are also influenced by technical codes that are not generally concerned with fire and life safety, as it pertains to the layout and construction of buildings.
Written By: Mark Richards, PE