TM 1-1500-204-23-1 • Rubbing  between  a  cowl  brace  and  a  sensing element. • Correct grommet installation. • Thermocouple detector mounting brackets should  be  repaired  or  replaced  when  cracked, corroded, or damaged. d. Troubleshooting   of   Fire   Detection   Systems.      A typical  troubleshooting  chart  for  fire  detection  systems  is shown in table 9-5. e. Repair    or    Replacement    of    Fire    Detection Components. Repair or replace fire detection components using the following procedures: (1) Replace     defective     control     unit     with     a serviceable unit. CAUTION Do  not  bend  sharply,  kink,  or  twist sensing element  during  installation Minimum  allowance  curve  radius  is one   inch.      Damage   may   otherwise result Table 9-5.  Troubleshooting of Fire Detection Systems Trouble Probable cause Remedy 1.  Intermittent alarms a.  Short In the detector system Repair or replace defective wiring wiring. b.  Kinks and bends in sensing Repair damaged areas of element sensing element. 2.  False alarms a.  Short between loop con- Repair or replace defective nections and control units wiring. b.  Bent areas of sensing loop in Repair bent areas of sensing contact with hot parts of the loop. engine c.  Short In the sensing loop Replace shorted section of sensing loop. d.  Moisture in detection system Remove moisture contamina- tion. 3.  Failure to obtain an alarm a.  Defective test switch or control Replace test switch or control signal when the test switch unit unit. Is actuated b.  Lack of electrical power Provide electrical power. c.  Inoperative Indicator light Replace indicator light. d.  An opening in sensing element Repair sensing element or or connecting wiring connecting wiring. 9-36