(1)
Except as permitted by Sentence (3), a fire alarm system shall be designed so that when an alarm signal is actuated, it cannot be silenced automatically before a period of time has elapsed that is not less than
(a)
5 min for a building not required to be equipped with an annunciator, and
(b)
20 min for any other building.
(2)
Except as permitted by Sentences 3.2.4.18.(8) and Sentences 3.2.4.22.(2) and (3), a fire alarm system shall not incorporate manual silencing switches other than those installed inside the fire alarm control unit. (See Note A-3.2.4.6.(2))
(3)
Except as provided by Clause 3.2.4.22.(3)(a), in a care and treatment occupancy an alert signal is permitted to be silenced automatically after 1 min.