Section 76.27-35 - Installation(a) Detectors must be located in all spaces except those having little or no fire risk such as void spaces with no stowage of combustibles, private bathrooms, public toilets, fire extinguishing medium storage rooms, deck spaces, and enclosed promenades that are naturally ventilated by permanent openings.(b) The detectors must be located on the overhead in the space protected at a minimum distance of 18 in (0.5 m) away from bulkheads, except in corridors, lockers, and stairways. Positions near beams and ventilation ducts, or other positions where patterns of air flow could adversely affect performance should be avoided. Where liable to physical damage, the detector must be suitably protected.(c) Detectors must be located in accordance with spacing requirements as tested and approved.(d) Detectors in stairways must be located at least at the top level of the stairs and at every second level beneath.(e) There must be at least one manual alarm station in each zone.(f) Manual alarm stations must be located in main passageways, stairway enclosures, public spaces, or similar locations where they will be readily available and easily seen in case of need.(g) A sufficient number of manual alarm stations must be employed to enable a person escaping from any space to find a manual alarm station on his or her normal escape route.(h) Cables that form part of a fire detection and alarm system must be arranged to avoid galleys and machinery and other high fire risk spaces except where it is necessary to provide for fire detection and alarms in such spaces or to connect to an appropriate power supply.(i) Clear information about the installation and operation of a fire detection and alarm system must be displayed on or adjacent to its control panels.(j) The audible alarms must be identified as required by § 78.47-13 of this subchapter.(k) The entire main vertical zone containing an atrium must be protected throughout with smoke detectors.