TM 9-4940-342-14&P CHAPTER 5 DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE INSTRUCTIONS Section I. REPAIR PARTS, SPECIAL TOOLS AND EQUIPMENT 5-1.  Special Tools and Equipment There    are    not    special    tools    and    equipment required for the maintenance of the steam cleaner. 5-2.  Repair Parts and Equipment Repair    parts    and    equipment    are    listed    and illustrated in the repair parts and special tools list covering    direct    support    and    general    support maintenance for the steam cleaner in appendix C of this manual. WARNING Before   accomplishing   any   repairs   to   the   steam cleaner,    shut    unit    down    and    allow    to    cool. Disconnect   power   cord,   failure   to   do   so   could cause     severe     injury     and     possible     death     to personnel. Section II. TROUBLESHOOTING 5-3.  General a.  This section contains troubleshooting information for locating and correcting most of the malfunctions   which   may   develop   in   the   steam cleaner.     Each     malfunction     for     an     individual component,  unit  or  system  is  followed  by  a  list  of probable causes and corrective actions. Maintenance personnel should check out the probable causes for a malfunction and perform the corrective actions in the order listed. b.  This  manual  cannot  list  in  table  5-1  all  the malfunctions   that   may   occur,   nor   all   probable causes  and  corrective  actions.  If  a  malfunction  is not listed or is not corrected by the listed corrective actions,    the    maintenance    supervisor    shall    be notified. Table 5-1.  Troubleshooting Malfunction Probable Causes Corrective Action 1.  Pump control switch closed, motor does not start. a.  115V control circuit fuse blown. a.  Remove   and   inspect   6   amp   fuse. Determine cause of blown fuse (short circuit, overload, grounded con- ductor).    Repair    fault    and    replace fuse. b.  Magnetic motor starter overload switch X2 open. b.  Depress magnetic starter reset button.  Switch  X2  should  close  and the motor start. Stop motor, determine cause of condition causing overloading    of    motor    before    con- tinuing    operation    (binding    or    ob- struction in pumps). c.  Power supply to steam cleaner interrupted. c.  Zero  voltage  at  terminals  L1  and  L2 of  magnetic  motor  starter.  Check  for 220V    AC    potential    at    the    power supply source. d.  Excess pressure switch open. d.  Zero voltage between circuit 1 and 2 at control terminal board. See malfunction 7. e. Defective stepdown transformer. e.    Low    or    zero    voltage    across    the transformer    primary    terminals    H1 and   H4   should   be   220-240V   AC. Check terminals for tightness. 25