TM 55-1930-209-14&P-16 Table 4-2.  Troubleshooting Procedures for HAC System Condition Possible Cause Suggested Action 1.  AC compressor a.  Improper switch set- a.  Make sure all switch does not start tings settings are correct b.  Thermostat set too b.  Turn right control high on AC controls fully clockwise c.  Five-minute delay c.  Wait 5 minutes switch activated to protect unit d.  Low on refrigerant d.  Notify support maintenance 2.  AC not cooling a.  Improper switch set- a.  Make sure all switch tings settings are correct b.  Dirty air filter b.  Clean or replace filter c.  Loose or broken fan c.  Tighten or replace belt fan belt d.  Condenser coils dirty d.  Clean condenser coils e.  Improper valve set- e.  Make sure valves are set tings properly for water source being used f.  Insufficient waterflow f.  Check seawater strainer from AC water pump pressure, if drop exceeds 2.0 psi, switch baskets and dean strainer g.  Warm cooling water/ g.  Allow AC compressor to high humidity operate** 3.  AC operates a.  Fan belt loose or worn a.  Tighten or replace belt noisily b.  Belt sheaves loose or b.  Align sheaves and tighten out-of-alignment c.  Fan blades bent or c.  Clean fan blades; if dirty vibration can be felt in AC cabinet, adjust fan blades 4   Compressor a.  Improper switch set- a.  Make sure all switch short cycles tings settings are correct b.  Filter dirty b.  Clean or replace filter c.  Fan belt slipping c.  Tighten fan belt d  High/low pressure d.  Notify support maintenance switches malfunctioning 5.  Heating unit a.  Improper switch set- a.  Make sure all switch does not operate tings settings are correct b.  Filter is dirty b.  Clean filter c.  Fan belt slipping c.  Tighten fan belt d.  Internal fuse(s) blown d.  Replace fuse(s) e.  Safety circuits not e  Notify support maintenance functioning properly **  On  extremely  humid  days,  AC  compressor  may  run  for  several  hours  without  any  significant  reduction  in temperature  in  conditioned  area.    However,  humidity  content  of  air  being  conditioned  will  be  greatly  reduced  and conditioned area will be more comfortable in spite of negligible reduction In temperature 4-10