From: David MacLeod, C.E.I, P.Eng., Chief Electrical Inspector
Date: Original issue date: November 6, 2003
Rev. 1-Sept 1,2006
As mandated by the National Building Code (NBC) and CAN/ULC - S524 -01 all fire alarm(F/A) systems shall be wired per CAN/ULC -S524-01 and the Canadian Electrical Code (CEC) section 32. (see notes 1 & 3).
For the purpose of this Bulletin a mandated F/A system is a system that is required and described as per section 3.2.4 of the NBC.
Also a system installed on a voluntary basis designed to warn of an emergency fire condition in a building consisting of at least the following interconnected devices - a control unit (see note 2) - a manual pull station and an audible signal device shall also be considered a F/A system.
Therefore the wiring requirements of CEC section 32 shall apply to both mandated F/A systems and F/A systems installed on a voluntary basis as described above (see note 5).
Other fire alarm installations not mandated by the NBC or not falling within the definition of a voluntary installed F/A system are not required to comply with section 32 of the CEC nor are they required to be verified in order to receive a final electrical inspection, however they are subject to the general wiring requirements of the CEC .
Smoke alarms that are directly supplied from an alternating current (AC) circuit and installed in dwelling units shall be wired per section 32-110 of the CEC.
As of Sept 1, 2006 as a result of changes in the Nova Scotia Building Code Regulations, smoke alarms which are directly powered and interconnected to a household fire warning system will be permitted to be installed in dwelling units as an alternate to directly supplied AC smoke alarms.
The above mentioned smoke alarms must be CAN/ULC- S531 approved and a component of a household fire warning system which includes a certified control unit that meets the applicable requirements of ULC-S545 “Standard for Residential Fire Warning System Control Units” and in case the regular power supply to the control unit is interrupted, be provided with a battery as an alternate power source that can continue to provide power to the control unit for a period of no less than 24 hours in the normal condition, followed by five minutes of alarm.
The above requirements are mandated by the NS Building Code Regulations and any one who fails to comply with these requirements may be guilty of an offence and be liable, on summary conviction, to a fine or have an order being issued under the Building Code Act.
The electrical power supply and wiring to the household fire warning system and the wiring methods to and between the associated smoke alarms must comply with all the requirements of rule 32-110 of the CEC (see note 5).
In particular the power supply to the household fire warning system shall be connected to a lighting circuit or circuit that supplies a mix of lighting and receptacles and not suppled from a circuit protected by a GFCI or AFCI.
Smoke alarms installed in dwelling units which are directly powered and interconnected to a household fire warning system as described above do not meet the definition of a fire alarm system and do not need to be verified to obtain a final electrical inspection.
Also as of Sept 1, 2006 as a result of changes in the Nova Scotia Building Code Regulations smoke alarms as required by the NBC and directly fed from an AC circuit are required to have battery backup.