(1) Except as provided in Sentences (2) and (3), smoke alarms required in Sentences 9.10.19.1. (1) and 9.10.19.3. (2) shall,
(a) be installed with permanent connections to an electrical circuit,
(b) have no disconnect switch between the overcurrent device and the smoke alarm, and
(c) in case the regular power supply to the smoke alarm is interrupted, be provided with a battery as an alternative power source that can continue to provide power to the smoke alarm for a period of not less than 7 days in the normal condition, followed by 4 min of alarm.
(2) Where the building is not supplied with electrical power, smoke alarms are permitted to be battery operated.
(3) Suites of residential occupancy are permitted to be equipped with smoke detectors in lieu of smoke alarms, provided the smoke detectors,
(a) are capable of independently sounding audible signals within the individual suites,
(b) except as provided by Sentence (4), are installed in conformance with CAN/ULC-S524, “Installation of Fire Alarm Systems”, and
(c) form part of the fire alarm system.
(4) Smoke detectors permitted to be installed in lieu of smoke alarms as provided in Sentence (3) are permitted to sound localized alarms within individual suites, and need not sound an alarm throughout the rest of the building.