(a) General.
(1) The primary source shall be an a.c. primary power source, which is preferred, or a monitored battery primary source.
(2) All power supply shall be sufficient to operate the alarm signal for at least four continuous minutes.
(b) A.C. Primary Power Supply.
(1) An a.c. primary power source of electrical power, use, shall be a dependable commercial light and power supply source. A visible power indicator shall be provided.
(2) A cord-connected installation is acceptable, provided that the installation makes use of a receptacle not subject to loss of power by a wall switch. A restraining means shall be used at the plug-in.
(3) Neither loss nor restoration of primary power shall cause an alarm signal.
(c) Monitored Battery Primary Power Sources. Smoke detectors may be powered by a battery, provided that the battery is monitored to assure that the following conditions are met:
(1) All power requirements are met for at least one year's life, including routine testing.
(2) A distinctive audible trouble signal is given before the battery is incapable (from aging, terminal corrosion and other causes) of operating a device for alarm purposes.
(3) For a unit employing a lock-in alarm feature, automatic transfer is provided from alarm to a trouble condition. If a unit does not have a lock-in feature, automatic transfer from alarm to trouble is not required.
(4) The unit is capable of providing an alarm signal for at least four minutes at the battery voltage at which a trouble signal is normally obtained, followed by seven days of trouble operation.
(5) The audible trouble signal is produced at least once every minute for seven consecutive days.
(6) The monitored batteries meeting these specifications are clearly identified on the unit, near the battery compartment.
(d) Combination System.
(1) When common wiring is employed for a combination system, the equipment for other than the fire warning signal system shall be connected to the common wiring of the system so that short circuits, open circuits, grounds or other fault in the equipment or interconnection between the equipment and the fire warning system wiring shall not either interfere with the supervision of the fire warning system or prevent alarm or trouble signal operation.
(2) In a combination system, a fire alarm shall take precedence or be clearly recognizable over any other signal even when the nonfire alarm system is initiated first. Distinctive alarm signals shall be obtained between fire alarm and other functions, such as burglar alarm.
(Ord. 2030. Passed 12-17-79.)