Each required smoke detector shall be mounted on the ceiling, or a wall not more than 12 inches from the ceiling, at a point centrally located in a corridor or area giving access to rooms used for sleeping purposes. In an efficiency dwelling unit, the detector shall be centrally located on the ceiling of the main rooms. Where sleeping rooms are on an upper level, the detector shall be placed at the center of the ceiling directly above the stairway. Care should be exercised to ensure that the installation will not interfere with the operating characteristics of the detector. When activated, the detector shall provide an audible alarm in the dwelling unit. Smoke detectors with D.C. power supply only are permitted, as are detectors with A.C. power supply backed up by a secondary supply which is D.C. An A.C. only powered unit is not permitted for residential type occupancies. Where A.C.-D.C. combination units are used, it is required that all A.C. lines be wired directly to the building’s power supply. All D.C. powered detectors shall have built-in protection to warn of battery failure.
(1999 Code, § 6-4-3) Penalty, see § 150.999