(a) Each detector in an electric fire detection system must be located where--
(1) No portion of the overhead of a space protected is more than 3 meters (10 feet) from a detector;
(2) Beams and girders extending below the ceiling of the space protected and any other obstructions do not detract from the effectiveness of the detector; and
(3) Damage to the detector is unlikely to occur if it is not protected.
(b) Each detector must be set to activate at not less than 57 [deg]C (135 [deg]F) and at not more than 73 [deg]C (165 [deg]F), except that if a space normally has a high ambient temperature each detector may be set to activate at not less than 80 [deg]C (175 [deg]F) and not more than 107 [deg]C (225 [deg]F).