It is exciting to receive readers’ e-mails and phone calls with questions on application requirements of the Canadian Electrical Code, Part I (CE Code), and the National Building Code of Canada (NBC). In fact, one reader [an electrical inspector and part-time BCIT Code instructor] even challenged me on the recently published article on transformers loading, and I discussed this matter with him.
This article is a compilation of such 8 questions (and respective 8 answers) regarding provisions of the NBC and the CE Code for electrically connected life safety systems.
Question #1
Is a smoke detector at the top of a stair interconnecting two floors, permitted to be indicated together with the smoke detectors installed around baffles for interconnecting stairs, and be connected to the same fire alarm initiating zone?
Answer #1
A smoke detector is required at the top of the exit stair shaft by Sentence 3.2.4.10.(1)(e) of the NBC. It should be noted that an exit stair shaft must always be enclosed, and this is the reason that a smoke detector at the top is intended to capture the rising smoke. This smoke detector must be represented by a dedicated fire alarm initiating zone in conformance with Sentence 3.2.4.8.(2)(c) of the NBC. Smoke detectors are required by Sentence 3.2.4.11.(1)(f) of the NBC in the vicinity of draft stops mandated by Article 3.2.8.6. of the NBC. These smoke detectors must be represented by a separate/dedicated fire alarm initiating zone on the fire alarm system annunciator.
These smoke detectors are not permitted to be connected to the same fire alarm initiating zone, which represents a smoke detector at the top of an exit shaft. Interconnecting stairs are open, and the smoke detectors required by Sentence 3.2.4.11.(1)(f) around baffles – in the vicinity of draft stops mandated by Article 3.2.8.6. of the NBC, are intended to provide early warning, if smoke will rise to the interconnected floor above the draft stops. A smoke detector at the top of such open interconnecting stairs is not required by the NBC, and installation of it at the top of an open stair is not warranted, as it will have difficulty capturing smoke in such open stairs.
Question #2
Is a wireless fire alarm system permitted by the NBC?
Answer #2
Sentence 3.2.4.5.(1) of the NBC states the following:
“1) Fire alarm systems, including the voice communication capability where provided, shall be installed in conformance with CAN/ULC-S524, “Standard for Installation of Fire Alarm Systems.”
Although ULC S524-2019 recognizes the use of wireless (short-range radio frequency) devices, it is a wiring standard, which applies to the installation of:
- input devices (manual and automatic fire alarm initiating devices),
- interface equipment (CPU, annunciators, CACF, transponders) and
- output devices (audible and visible signal devices), and electrical supervision of wiring circuits to the fire alarm system components is always required by ULS S524…
Clause 4.1 of ULC S524 states the following:
“4.1 A fire alarm system shall consist of at least the following interconnected devices: a control unit, a manual station and an audible signal device.”
Clause 5.1.4 of ULC S524 states the following:
“5.1.4 The fire alarm system power supply equipment and wiring shall be installed in conformance with this Standard and the requirements of CSA C22.1, Canadian Electrical Code, Part I, Safety Standard for Electrical Installations, Section 32.“
Electrical supervision of circuits (wiring) is required in accordance with Clause 6.1.1 of ULC S524, and electrical supervision is defined as follows:
“3.37 ELECTRICAL SUPERVISION – A means whereby a fault condition which would interfere with the operation of a circuit / pathway in a fire alarm system is detected.”
Therefore, the entire system must be wired. However, some devices could be wireless (by means of short-range radio frequency), if the power supply to such wireless devices is provided by batteries in accordance with ULC S524.
Question #3
Is installation of exit signs depicting “running man” moving away from the latching sign of the door permitted by the NBC?
Answer #3
The direction of the “running man” on the exit sign shown below, does not violate provisions of Article 3.4.5.1. of the NBC, and the “running man” should not necessarily face the latching side of the door. In Photo 1, the manufactured exit sign conforms to CSA standard C22.2 No. 141. As such pictogram is consistent with the provision of C22.2 No. 141 for approved electrical equipment.
It should be noted that the CE Code users must use only approved equipment. In this case, the electrically connected exit sign certified to C22.2 No. 141 must be used with the pictogram conforming to the standard unless a directional sign is used in conformance with Sentence 3.4.5.1. (6) of the NBC (see photo 2).
Question #4
To what extent upgrade of the emergency distribution must comply with the provisions of the CE Code?
Answer #4
The answer is based on the following conditions:
a) When an emergency generator is intended to be replaced with a generator that has similar electrical characteristics as the existing generator, the scope of electrical work is limited to the replacement of the generator, and such work does not impact the existing emergency distribution.
b) When the emergency generator is upgraded, but the existing emergency distribution on the load side of a single overcurrent device and disconnecting means for this generator (as described in Clause 8.7.1 of C282) remains unchanged. In addition to the scope of work described in item 1 above, the generator, the emergency power supply system bus, and the disconnecting means with the O/C device conforming to Clause 8.7.1 of C282 must also be upgraded accordingly.
c) If the entire emergency distribution system is subject to change, all relevant provisions of the NBC, C282, and Section 46 of the CE Code must be met.
d) If the new life safety loads are intended to be connected to the existing emergency distribution, which is provided with the single automatic transfer switch (ATS), then the new life safety ATS must be added for such life safety loads in conformance with Section 46 of the CE Code. Of course, the fire pump feeder must be provided with the dedicated ATS, conforming to Rule 32-308 of the CE Code.
e) If the new non-life safety loads are intended to be connected to the existing emergency distribution, which is provided with the single ATS, then the additional non-life safety ATS may not be required for installation, as such additional non-life safety loads will be outside the scope of Section 46 of the CE Code (scope of this Section applies only to the emergency power supply and life safety systems), and their addition should not compromise already existing nonconforming arrangement of the emergency distribution. If, however, the local AHJ is of the opinion that the addition of such non-life safety loads will further compromise already non-conforming emergency distribution, the AHJ may insist on providing the new non-life safety ATS for these newly added non-life safety loads.
Question #5
Is a trouble signal during alarm required from a sprinkler tamper by Sentence 3.2.4.9.(3)(a) of the NBC?
Answer #5
There is a difference between a trouble signal during an alarm mode (trouble signal which indicates a short circuit/ground fault or open circuit) and any supervisory signal mandated by Article 3.2.4.9. of the NBC.
While a trouble signal indicating an open/short circuit is non-essential during a fire alarm mode (when the alarm signal provides the critical early warning to the occupants), supervisory condition mandated by Article 3.2.4.9. for standpipe, sprinkler system, or a fire pump is crucial for fire suppression/fire fighting activities during the alarm mode or during the time when the FAS is reset, and as such ULC S524 assigns a much higher priority to these supervisory signals.
These supervisory signals represent ancillary circuits responsible for such activities as elevator homing, actuation of smoke control/smoke venting equipment, the release of electromagnetic locks or hold-open devices, signals to the fire department, and similar actions related to fire suppression functions.
This is the reason that signals related of the interconnection of ancillary devices with a fire alarm system, including indication of such supervisory conditions on the annunciator, must be provided within 10 seconds of first input operation, and all such life safety equipment is subjected to integrated testing.
Respective ULC S524 definitions below provide additional clarity on this subject.
“3.83 SUPERVISORY DEVICE – A field device to detect a condition that could prevent the proper operation of a fire protection system.
3.84 SUPERVISORY SIGNAL – A visual and audible indication of the off-normal status of equipment that has been installed for the protection of life and property.
3.85 SUPPORTING FIELD DEVICE – An active field device that monitors and/or controls other field devices on a separate circuit and reports the status of the separate circuit to a control unit and/or transponder.
3.86 TAMPER DEVICE – A device to detect the removal or opening of a protective cover.
3.87 TRANSPONDER – A component in a distributed type system, which is capable of receiving inputs and activating outputs, and that communicates the status of such devices to the fire alarm system.
3.88 TROUBLE SIGNAL – A visual and audible indication of equipment failure, circuit failure, fault condition or operational malfunction.”
Question #6
Is a double-interlocked or cross-zone interlocked pre-action fire suppression system an integral part of a fire alarm system?
Answer #6
NFPA 13 recognizes a pre-action system to prevent accidental discharge of the wet sprinkler system into the area where specific equipment crucial for the process is installed or in IT server rooms.
Pre-action system is not part of a fire alarm system (FAS), and as such – the actuation of a per-action system (usually designed by the fire protection experts or by sprinkler contractors) does not have to activate a fire alarm system and sound the alarm signal.
However, if a pre-action system is designed as a part of the sprinkler system in accordance with NFPA 13, this pre-action system must be electrically supervised on the FAS annunciator similarly to other components of the sprinkler system in accordance with Sentence 3.2.4.9.(3) of the NBC, when this pre-action system is actuated.
In this case, the fire alarm system supervisory zone will indicate that the “pre-action system is activated”, which means that the valve controlling the water supply into the dry sprinkler pipe, is now open, and the sprinkler pipe operates as a wet sprinkler system, and when a sprinkler head (fusible link) is open, water flow detecting device referenced in Article 3.2.4.15. of the NBC will initiate the building FAS.
Double interlocks or cross zone interlocks in the pre-action system simply represent conditions under which the actuation of smoke sensors in the pre-action system will result in the opening of a valve that will allow water into the dray sprinkler pipe.
Double interlock means that when one smoke sensor and another smoke sensor of pre-action systems are activated (“and” logic), only then valve will open.
Question #7
Are 1-hour rated optical fiber cables recognized by a CSA standard for optical fiber cables?
Answer #7
Except for standard C22.2 No. 124 for MI cable (which has an optional fire resistance rating as a circuit integrity cable, not a single CSA safety standard for electrical products covers a fire-resistance rating, as fire resistance rating is assigned only to building materials in accordance with the NBC provisions.
Some cable manufacturers offer additional construction, testing, and marking requirements to the cables and conductors already certified to the applicable CSA safety standards for conductors and cable when these “circuit integrity cables” are subjected to “Fire Test for Evaluation of Integrity of Electrical Power, Data and Optical Fibre Cables” in conformance with ULC S139.
When such circuit integrity conductors or cables (power or optical fiber) pass the necessary test, then – in addition to the CSA certification monogram, such conductors and cables are provided by the manufacturer with 1 hour or 2 hour circuit integrity marking conforming to ULC S139.
Therefore, if an optical fiber cable certified to C22.2 No. 232, is also tested to ULC S139 as a circuit integrity cable, it will have a 1-hour or 2-hour fire resistance rating, and it will be marked accordingly.
Question #8
Is it the intent of Clauses 5.1 and 5.2 of C282 to restrict the installation of equipment that is part of the life safety system, but that is not listed under Clause 5.1 of C282, from being installed in the same generator service room?
Answer #8
The author’s comments (and conclusion) on this subject are as follows:
A. Article 3.6.2.8. of the NBC states:
“3.6.2.8. Emergency Power Installations
1) Where a generator intended to supply emergency power for lighting, fire safety and life safety systems is located in a building, except where such building is used solely for the purpose of housing the generator and its ancillary equipment, it shall be located in a room that
a) is separated from the remainder of the building by a fire separation having a fire-resistance rating not less than 2 h, and
b) contains only the generating set and equipment related to the emergency power supply system.”
The objective of the above NBC requirement is to protect the emergency power supply system from exposure to fire (generator and associated equipment) – by housing it in a dedicated, 2 h rated service room that does not contain any other equipment.
B. Emergency electrical power supply system is defined by C282 as follows:
“Emergency electrical power supply system — the local generation of electrical energy for supplying a load requiring emergency electrical power, as mandated by the NBCC, when the normal power supply fails.”
C. Clause 5.1 of C282 lists the components of the emergency electrical power system as follows:
“5 Emergency electrical power supply system
5.1 The emergency electrical power supply system shall consist of all of the equipment and systems necessary to supply reliable electrical power, including the following:
a) the engine generator set, which can include an auxiliary supply tank;
b) the lockable disconnecting means and overcurrent devices described in Clause 8.7.1;
c) the fuel supply system, including tanks and piping as described in Clause 7.3;
d) automatic transfer switches supplying the “essential electrical system” defined in Section 24 or the “life safety systems” defined in Section 46 of the Canadian Electrical Code, Part I;
e) the emergency generator ventilation and cooling system;
f) electrical components between an emergency generator and the transfer switches described in Item d), including but not limited to control and power wiring and overcurrent devices;
g) the overcurrent protective devices installed in the feeders supplying permanent or temporary load banks; and
h) the exhaust silencer and piping to outdoors.”
It means that except for the generator and listed components of the emergency power supply system, no other equipment is permitted by the NBC – to be located in the service room dedicated to the emergency power supply. It means that life safety distribution equipment also is not allowed to be located in this service room, as any fire on such distribution equipment (although it is life safety equipment) may adversely impact the operation of the emergency power supply equipment. It should be noted that life safety distribution equipment is located on the load side of any life safety transfer switch, and such life safety distribution equipment is not a part of an emergency electrical power supply system.
D. Note 1 on Clause 5.2 of C282 clarifies that not all components of the emergency electrical power supply system must be located in the generator service room (i.e., a transfer switch for a fire pump is usually located in the fire-rated service room containing a fire pump and a fire pump controller):
“5.2 Unless otherwise specified by the authority having jurisdiction or as required by the NBCC, all of the components specified in Clause 5.1 shall be separated from the remainder of the building by a fire separation with a fire-resistance rating of not less than 2 h.
Notes:
1) Not all of the components need be in the same room or other location in the building.
2) See Clause B.1 for commentary on this Clause.
3) The fire-resistance rating for a room that contains any fuel storage, such as the auxiliary supply tank, might need to be increased in accordance with the requirements of CSA B139 and/or the authority having jurisdiction depending on the volumes of storage in each room.”
E. Rule 46-204 of the CE Code and Appendix B Note on this Rule clarify that conductors between the emergency generator and components of the emergency electrical power supply system not located in the generator service room, must be protected against exposure to fire (see below):
“46-204 Protection of electrical conductors and cables (see Appendices B and G)
All power, control, and communication insulated conductors and cables between an emergency generator as described in Rule 46-202 3) and electrical equipment required to be installed as a part of the emergency power supply and located outside the generator room shall be protected against fire exposure to provide continued operation in compliance with the National Building Code of Canada.”
“Appendix B Note on Rule 46-204
The intent of this Rule is to protect electrical conductors and cables between an emergency generator and associated electrical equipment, such as the transfer switch(es), bypass switch(es), engine control panel, etc., required to be installed as a part of the emergency power supply and located outside the generator room against exposure to fire for a period not less than 1 h. The National Building Code of Canada requires that electrical conductors and cables supplying life and fire safety equipment be protected against such exposure. CSA C282 also mandates protection of circuits interconnecting field-installed equipment forming part of an emergency generator against possible damage by fire.”
Conclusion
The service room containing the emergency electrical power supply equipment (generator and associated equipment listed in Clause 5.1 of C282) is not permitted to contain any other equipment which does not belong to the emergency electrical power supply system.
Portions of the emergency electrical power supply system are allowed to be located outside of the dedicated 2 hour rated service room that contains the emergency generator, but such components of the emergency power supply system must be located in a service room with a fire resistance rating of not less than 1 hour, as required by Sentence 3.6.2.1.(8) of the NBC.
The NBC does not restrict service rooms referenced in item 5.2 above to the installation of life safety equipment only. Such service rooms may contain components of the emergency electrical power supply systems, clarified in Appendix B Note on Rule 46-204 of the CE Code, life safety distribution equipment, and non-life safety distribution equipment, provided that such service rooms have fire resistance rating of not less than 1 hour.
Hopefully, answers to the posted questions help to clarify raised subjects. And as usual, local AHJs should be consulted on issues related to specific installations.
