It is very encouraging to receive e-mails and phone calls from readers with questions on Code-related issues.
Provisions of the CSA standard C22.2 No. 141 “Emergency Lighting Equipment,” requirements of the National Building Code of Canada (NBC) and of the Canadian Electrical Code, Part I (CE Code) are used in this article – to address questions “What is emergency Lighting,” why and where it is required to be installed, and how to install emergency lighting to ensure that it performs as intended.
Readers should be aware that the 2020 edition of the NBC and 2021 edition of the CE Code are referenced in the answers to the posted questions.
What is emergency lighting?
While the NBC provides very detailed requirements for emergency lighting in certain areas of farm buildings, buildings under the provision of Part 3 of the Code (buildings for all types of occupancy and all sizes) and buildings covered by Part 9 (except for buildings of assembly occupancy, for all types of buildings containing three storeys or less in building height and having a building area not exceeding 600 m2), the NBC does not define “emergency lighting.”
However, the CE Code defines emergency lighting as follows:
“Emergency lighting — lighting required by the provisions of the National Building Code of Canada for the purpose of facilitating safe exit and access to exit in the event of fire or other emergency.”
This definition clarifies to the Code users that emergency lighting required by the NBC must function so, as to facilitate safe egress from a building under emergency conditions when a normal power supply source to the lighting may be interrupted.
In which areas does the NBC mandate emergency lighting in a building?
This discussion will not cover the NBC provisions for emergency lighting in farm buildings, but in buildings governed by Part 3 and Part 9 of the NBC, emergency lighting must be provided as follows (readers are welcome to independently review the NBC clauses referenced in the list below):
Article 184.108.40.206. mandates that in Part 3 Buildings, emergency lighting must be installed in:
b) principal routes providing access to exit in open floor areas and in service rooms,
c) corridors used by the public,
d) corridors serving sleeping rooms in a treatment occupancy,
e) corridors serving sleeping rooms in a care occupancy, except corridors
serving sleeping rooms within individual suites of care occupancy,
f) corridors serving classrooms,
g) underground walkways,
h) public corridors
i) floor areas or parts thereof where the public may congregate
i) in Group A, Division 1 occupancies, or
ii) in Group A, Division 2 and 3 occupancies having an occupant load of 60 or more,
j) floor areas or parts thereof of daycare centres where persons are cared for,
k) food preparation areas in commercial kitchens,
l) public washrooms that are equipped to serve more than one person at a time,
m) locations where doors are equipped with an electromagnetic lock as described in Clauses 220.127.116.11.(5)(k) and (6)(g), and
n) universal washrooms, universal shower rooms and accessible change spaces required by Article 18.104.22.168.
o) a service space referred to in Sentence 22.214.171.124.(8).”
Sentence 126.96.36.199.(1) requires that in Part 9 buildings, emergency lighting must be installed in
b) principal routes providing access to exit in an open floor area,
c) corridors used by the public,
d) underground walkways, and
e) public corridors.”
In addition to these NBC requirements, CSA standard C282 “Emergency Electrical Power Supply for Buildings,” which applies to emergency generators, mandates that a unit equipment for emergency lighting must be installed in an emergency generator room and in a service room that houses an automatic transfer switch for life safety equipment. Clause .6.11.1 of C282 states the following:
The service room or enclosure containing the emergency electrical power supply and the service room containing the automatic transfer switch(es), shall be equipped with unit equipment for emergency lighting that complies with CSA C22.2 No. 141.”
It should also be noted that a similar requirement exists in Clause 6.5.1.(b) of the CSA standard Z32 as follows:
“6.5.1 Illumination levels, duration, and location
Additional emergency lighting that complies with CSA C22.2 No. 141 shall provide battery-operated emergency lighting,
b) for the tasks performed in the following areas:
i) operating rooms;
ii) delivery rooms;
iii) angiographic laboratories;
iv) cardiac catheterization laboratories; and
v) other patient care areas where a procedure may be in progress, and cannot be interrupted.“
What is the illumination level required by the NBC for emergency lighting, and for what period of time emergency lighting must provide this required illumination level?
NBC mandates the following illumination levels in all those areas where emergency lighting is mandated by the Code: “Emergency lighting shall be provided to an average level of illumination not less than 10 lx at the floor or tread level.” In addition to the requirements for an average illumination level, the NBC also states that the minimum illumination level provided by emergency lighting must be as follows: “The minimum value of the illumination required by Sentence (4) shall be not less than 1 lx.”
While Sentence 188.8.131.52.(3) states that in the areas required to be provided with emergency lighting in Part 9 building, emergency lighting must operate at not less than 30 min “(3) Lighting required in Sentence (1) shall be designed to be automatically actuated for a period of at least 30 min when the electric lighting in the affected area is interrupted,” Sentence 184.108.40.206.(1)(b) of the NBC lists different time requirements for illumination by emergency lighting in buildings governed by Part 3 as follows:
Emergency power supply must be:
“So, designed and installed that upon failure of the regular power, it will assume the electrical load automatically for a period of
i) 2 h for a building within the scope of Subsection 3.2.6.,
ii) 1 h for a building of Group B major occupancy classification that is not within the scope of Subsection 3.2.6.,
iii) 1 h for a building constructed in accordance with Article 220.127.116.11. or 18.104.22.168., and
iv) 30 min for a building of any other occupancy.”
As was indicated earlier, the readers are welcome to review the NBC clauses referenced in the list above independently.
It should be noted that provisions of C282 mandate more restrictive performance requirements for unit equipment for emergency lighting mandated to be installed in a service room for an emergency generator and in a service room containing a life safety transfer switch, as follows:
The service room or enclosure containing the emergency electrical power supply and the service room containing the automatic transfer switch(es), shall be equipped with unit equipment for emergency lighting that complies with CSA C22.2 No. 141. Sufficient lamps shall be provided to ensure that a minimum lighting level of 50 lx for 2 h is available at all equipment locations requiring adjustment or service.
Note: This illumination level is significantly greater than that specified in the NBCC, which requires 10 lx for egress route emergency lighting.”
Similar to C282, Z32 also mandates more restrictive performance requirements for a unit equipment for emergency lighting in accordance with Clause 6.5.1.(a), as follows:
“6.5.1 Illumination levels, duration, and location
Additional emergency lighting that complies with CSA C22.2 No. 141 shall provide battery-operated emergency lighting of an average illumination level of 50 lux for a duration of 2 h.”
What are the emergency power supply sources for emergency lighting required by the NBC?
The NBC offers the option of a battery or a generator to serve as an emergency power supply source for emergency lighting in Part 3 buildings, where an emergency generator could also be required for different reasons:
“22.214.171.124. Emergency Power for Lighting
1) An emergency power supply shall be
a) provided to maintain the emergency lighting required by this Subsection from a power source such as batteries or generators that will continue to supply power in the event that the regular power supply to the building is interrupted.”
In buildings covered by Part 9 requirements, Sentence 126.96.36.199(2) of the NBC simply states that an emergency power supply source must be separate from a normal power supply source to a building, and Sentence 188.8.131.52.(7) recognizes the use of self-contained emergency lighting units conforming to C22.2 No. 141, as follows:
“184.108.40.206. Emergency Lighting
2) Emergency lighting required in Sentence (1) shall be provided from a source of energy separate from the electrical supply for the building.
7) Where self-contained emergency lighting units are used, they shall conform to CSA C22.2 No. 141, “Emergency lighting equipment.”
Rule 46-202 of the CE Code echoes these NBC provisions as follows:
“46-202 Types of emergency power supply
1) The emergency power supply shall be a standby supply consisting of
a) a storage battery of the rechargeable type having sufficient capacity to supply and maintain at not less than 91% of full voltage the total load of the emergency circuits for the time period required by the National Building Code of Canada, but in no case less than 30 min, and equipped with a charging means to maintain the battery in a charged condition automatically; or a generator.“
Is a UPS allowed to be used as an emergency power supply source for emergency lighting?
No. The NBC and the CE Code are very specific in mandating a battery, and not a UPS, as the scope of the CSA standard 107.3 for uninterruptible power systems (harmonized with UL standard UL 1778) excludes the use of UPS as an emergency power supply source for life safety systems (see below):
These requirements do not cover UPS units for use as legally required standby systems, described in Article 701 of the National Electrical Code, ANSI/NFPA 70, and emergency power supply described in Section 46 of the Canadian Electrical Code, Part I, CSA C22.1.“
Is battery-based central power supply recognized by the C22.2 No. 141 “Emergency lighting equipment?
Yes. C22.2 No. 141 applies to a central battery system and to a unit equipment for emergency lighting as a power supply source for emergency lighting as follows:
“Central power system — systems equipment consisting of a central storage battery bank, automatic battery charging equipment with or without a low frequency inverter, automatic control relays, multi-circuit distribution equipment, derangement alarm equipment, and other applicable accessories. Such equipment may be integrally housed in a single overall enclosure or may be separately enclosed for remote connection to a central control unit.”
“Unit equipment for emergency lighting — equipment that
a) is intended to provide automatically, in response to a failure of the power supply to which it is connected, a specified light output and a specified amount of power for illumination purposes, for a specified period of time, but in any case not less than 30 min;
b) comprises, in a unit construction
i) a storage battery;
ii) a charging means to automatically maintain the battery in a charged condition;
iii) lamps or output terminals to which specifically listed lamps can be connected;
iv) a means to energize the lamps when the normal power supply fails and to de-energize the lamps when the normal power supply is restored; and
v) a means to indicate and test the operating condition of the equipment;
c) is designed for use in applications in which the provision of emergency illumination is required by a governmental or other agency having jurisdiction; and
d) has a total maximum capacity of 1.44 kW and can be constructed with a frequency inverter.”
What are the requirements for installation of a unit equipment for emergency lighting?
Installation provisions for a unit equipment are governed by Rule 46-304 of the CE Code as follows:
“46-304 Supply connections
1) Receptacles to which unit equipment is to be connected shall be not less than 2.5 m above the floor, where practicable, and shall be not more than 1.5 m from the location of the unit equipment.
2) Unit equipment shall be permanently connected to the supply if
a) the voltage rating exceeds 250 V; or
b) the marked input rating exceeds 24 A.
3) Where the ratings in Subrule 2) are not exceeded, the unit equipment shall be permitted to be connected using the flexible cord and attachment plug supplied with the equipment.
4) Unit equipment shall be installed in such a manner that it will be automatically actuated upon failure of the power supply to the normal lighting in the area covered by that unit equipment.”
What are the installation requirements for remote lamps provided with the unit equipment, for voltage drop in the circuit supplying remote lamps and for overcurrent protection of the circuit supplying these remote lamps?
Rule 46-306 of the CE Code and Appendix B Notes on this Rule provide comprehensive clarification for the installation of remote lamps connected to unit equipment.
“46-306 Remote lamps (see Appendix B)
1) The size of insulated circuit conductors to remote lamps shall be such that the voltage drop does not exceed 5% of the marked output voltage of the unit equipment, or such other voltage drop for which the performance of unit equipment is certified when connected to the specific remote lamp being installed.
2) Remote lamps shall be suitable for remote connection and shall be included in the list of lamps provided with the unit equipment.
3) The number of lamps connected to a single unit equipment shall not result in a load in excess of the watts output rating marked on the equipment for the emergency period required by the National Building Code of Canada, and the load shall be computed from the information in the list of lamps referred to in Subrule 2).”
Appendix B Notes on Rule 46-306:
“Rule 46-306 1)
Where approved unit equipment includes a list of lamps suitable for remote installations, the requirements of CSA C22.2 No. 141 take into account a voltage drop of 5% in the remote lamp’s circuit unless the list specifies that certain lamps conform to the requirements with a greater voltage drop.
Table D4 can be used to determine approximate permissible circuit lengths.
Rule 46-306 2)
The requirements of CSA C22.2 No. 141 are designed to ensure that any lamps forming part of the equipment or specified in a list provided with the equipment as suitable for remote connection, will not exhibit an undue diminution of light intensity during the emergency period.”
It should be noted that the Technical Committee for the CE Code has approved modification of Table D3 for voltage drop, and the revised Table D3 (which will be incorporated in 2024 edition of the CE Code, will reflect voltage drop requirements, lengths of the DC circuit conductors to remote lamps and the applicable conductor sizes. As such, Table D4 will be deleted from the 2024 edition of the CE Code, and Appendix B Note on Rule 46-306(1) will be revised accordingly.
It should also be noted that standard C22.2 No. 141 provides requirements for overcurrent protection devices that protect circuits for remote lamps, as these O/C devices are supplied with a unit equipment, when the use of remote lamps is specified by an electrical designer.
Clause 5.11.2 of C22.2 No. 141 offers the following requirements for O/C protection of circuits supplying remote lamps:
“5.11.2 Overcurrent protection
Unit equipment designed for connection to lamps in locations remote from the equipment shall have overcurrent protection for the circuits needed to supply the lamps, in accordance with the following:
a) the overcurrent device shall be rated or set at not more than 25 A;
b) the overcurrent device shall be contained within the unit enclosure; and
c) the overcurrent device shall be rated or set at not less than 125% of the output circuit rating.”
A proposal was submitted to Section 46 S/C – to add a clarification note on Rule 46-306, that O/C protection for remote lamps is provided with a unit equipment for emergency lighting.
Hopefully, this article helps with the subject at hand. And as usual, local AHJ should be contacted for specific questions related to each particular installation.