Application of certain types of electrical equipment may be governed by codes other than the Canadian Electrical Code (CEC). Emergency lighting and exit signs are good examples of such types of equipment.
In fact, the scope of Section 46 of the CEC, Part I states that this section applies to installation, operation and maintenance of emergency lighting and exits signs that are required by the National Building Code of Canada (NBCC). Although the scope of Section 46 covers other types of emergency equipment and systems, this article concentrates only on emergency lighting and exits signs. It is important to note that even if the emergency lighting and exit signs are not necessarily required by the NBCC, inspectors’ viewpoint is that if this equipment is installed it must comply with the installation requirements of the CEC (bonding, wiring methods, selection of the overcurrent protection, conductors sizes, etc.).
However, before we will analyze provisions of Section 46 for installation and operation of the emergency lighting and exit signs, it is beneficial to visit applicable sections of the NBCC that regulate application requirements for this electrically connected life and fire safety equipment.
Let’s start with the emergency lighting. Article 184.108.40.206 of the NBCC mandates that the emergency lighting must be provided in the following areas:
- principal routes that constitute access to exits in an open floor area,
- corridors used by the public,
- corridors serving patients’ sleeping rooms,
- corridors serving classrooms,
- underground walkways,
- public corridors,
- floor areas or parts of such floor areas where public may congregate in
a) theatres, movie houses and similar occupancies, where house lights are turned off or dimmed during a performance or
b) schools, assembly halls, churches, restaurants, meeting rooms, arenas and other such similar occupancies, if such occupancies have occupant load of 60 or more persons.
This information is essential to the designers of emergency lighting. It allows them to understand with a full certainty, where the emergency lighting must be installed. The NBCC also prescribes when such emergency lighting must be actuated, how it must perform and what power source must be used for the emergency lighting systems and equipment.
Article 220.127.116.11 of the NBCC states that an emergency power supply must be provided from a power source such as batteries or generators to maintain emergency lighting in each area listed in Article 18.104.22.168 when the normal power supply to that area is interrupted. The NBCC also mandates that the emergency power supply must be designed and installed so that it is: a) automatically actuated upon failure of the regular power and b) capable to perform for at least 30 minutes in each required area.
In a building that is classified as a hospital or a jail, the emergency lighting must function at least for an hour; and if the building is classified as a high building, then the emergency lighting must operate for at least 2h.
It is important to note that terms exit, floor area, and public corridors used in Article 22.214.171.124 are defined in the NBCC, and that the designers of emergency lighting must be cognizant on the extent of these definitions. For example, “Exit means that part of a means of egress, including doorways, that leads from the floor area it serves, to a separate building, an open public thoroughfare, or an exterior open space protected from fire exposure from the building and having access to an open public thoroughfare”.
Why is this definition important to the electrical designers and contractors? Because it will help them to understand that depending on the building design, an exit can include outside open spaces which will also require provisions for normal and emergency lighting. Therefore, electrical designers and contractors must consult with the building code practitioners to establish the boundaries of the exits in each specific project. This approach will assist them to identify accurately the areas where emergency lighting systems and equipment must be installed under requirements of section 46 of the CEC.
Now, we are in a familiar territory. Rules of Section 46 will have to be followed for installation of emergency lighting systems (Rule 46-200) and unit equipment (Rule 46-300), and for wiring methods (Rule 46-108).
Let’s now look at exit signs. Article 126.96.36.199. (2) of the NBCC mandates that every exit sign shall be illuminated continuously while the building is occupied. The NBCC considers two types of illuminated signs: internally illuminated (i.e., an exit sign is in essence a luminaire), and externally illuminated, when illumination of an exit sign is provided by normal or emergency lighting in the area where such exit sign is installed. Thus, regardless whether illumination of an exit sign is provided by an electrical circuit directly supplying this sign (internally illuminated) or by electrical circuits supplying lighting in the area where an exit sign is installed (externally illuminated), such exit sign must be illuminated continuously. This means that the emergency power for emergency lighting as discussed earlier, must be provided for illumination of an exit sign.
The NBCC also lists mandatory locations for exit signs.
Article 188.8.131.52 states that an exit sign must be placed over or adjacent to every exit door in a building more than 2 storeys in building height, in a building with occupant load more than 150 persons, in a room or floor area that has a fire escape as part of a required means of egress. In addition every egress door from rooms with occupant load more than 60 persons in occupancies such as theatres, movie houses, restaurants, dancing halls, licensed beverage establishments, etc., must be provided with an exit sign—for easy identification of the egress doorway.
Building code experts should be also consulted by the electrical designers and installers in order to identify accurately required locations for installation of electrically connected exit signs. And when this is done, Rule 46-400 of the CEC will guide the designers and contractors towards installation requirements and wiring methods.
It is interesting to note that Appendix G of the CEC provides a comprehensive cross-reference from Rules of Sections 46 to the applicable articles of the NBCC.
And as it is usually done in cases where life safety equipment and systems mandated by the NBCC and the CEC are intended for installation—authorities with jurisdictional power for application and installation of emergency lighting and exit signs must be consulted when these installations take place.