TM 1-1500-204-23-1 (2) Replace sensing element only when physical  damage  such  as  chafing,  bending,  twisting,  or breaking  has  occurred.    Replace  attaching  parts  when found to be defective. CAUTION Bends   will   not   be   less   than   two inches in radius. (3) Replace  cable  detector  only  when  physical damage  such  as  chafing,  bending,  twisting,  or  breaking has  occurred.    Make  all  bends  and  routing  with  fingers only.  Replace attaching parts when found to be defective (4) Replace mounting brackets of thermocouple    detectors    when    cracked,    corroded,    or damaged.   Replace   attaching   parts   when   found   to   be defective NOTE When replacing thermocouple detector, note which wire is connected to identified plug terminal of defective unit, and connect replacement in the same way. f. Testing   of   Fire   Detection   System         Test   fire detection system using the following procedures (1) Test system for proper operation by turning on  power  supply  and  placing  FIRE  DET  TEST  switch  in test  position  Red  warning  light  should  flash  on  within  10 seconds.  Turn switch and power off (2) Test required after repair or replacement of units in fire detector system or when system is Inoperative as follows • Replace  lamp  in  warning  light,  when  warning light does not flash on. • Polarity, ground, resistance, and continuity tests are   required   for   systems   with   thermocouple detect or units. • Resistance and continuity tests are required for systems     with     sensing     elements     or     cable detector units. WARNING • Repeated  or  prolonged  exposure to high concentrations of bromochloromethane (CB) or decomposition   products   should be   avoided.      CB   is   a   narcotic agent  of  moderate  intensity  but of    prolonged    duration.        It    is considered less toxic than carbon tetrachloride, methylbromide, or usual products of combustion.  Normal precautions should be taken while using bromochloromethane Including  use  of  oxygen  masks when available. Injury to personnel may otherwise result. • Monobromotrifluoromethane (CF₃Br)   is   highly   volatile   but   is not  easily  detected  by  Its  odor. Although   nontoxic,   it   must   be considered to be about the same as     other     freons     and     carbon dioxide, causing danger to personnel  primarily  by  reduction of   oxygen   available   for   proper breathing.  The liquid should not be  allowed  to  come  into  contact with     skin,     as     It     may     cause frostbite or low temperature burns. g. Fire Extinguishing Systems.  The fire extinguisher system  Is  the  one-shot  type  consisting  of  one  or  more charged containers of bromochloromethane or monobromotrifluoromethane (CB and CF₃Br), discharging tubing,   overboard   discharge   tube,   discharge   indicator, circuit breakers, and control panel switch.  The container is charged with bromochloromethane or monobromotrifluoromethane    under    pressure,    which    is discharged  through  tubing  Into  the  engine  compartments by actuating FIRE EXT switch to the ON position h. Maintenance     of     Fire     Extinguishing     Systems. Maintenance    of    fire    extinguisher    system    consists    of Inspection  and  replacement  of  defective  parts  using  the following procedures: (1) Check   for   specific   pressure   on   pressure gauge as given In applicable aircraft maintenance manual (2) Inspect   overboard   discharge   indicator   for evidence   of   system   being   discharged   due   to   thermal expansion. 9-37