TM 5-3895-374-24-1 Excessive Belt Wear 1. Pulley out of alignment 1. Realign pulley with flywheel Check alignment See page 14. 2. Improper belt tension 2. Readjust See page 14. 3. Pulley wobbles 3. Replace the pulley and check for a damaged crankshaft or flywheel. Compressor Won’t 1. Too much back pressure In   1. Open petcock when starting motor. Start in Cold tank Temperature 2. Using wrong grade oil 2. Use ISO 100 (30W) premium compressor oil See page 12. 3. Compressor too cold 3. Move compressor to a warmer location. TROUBLESHOOTING THE MAGNETIC STARTER PROBLEM POSSIBLE CAUSE SOLUTION COMPRESSOR WON’T RUN 1. Motor hums but 1 Fuse blown in main panel if 1 Check and replace fuse in main panel. won’t turn 3 phase system 2 Low voltage to compressor 2 Motor wired for wrong voltage See ’footnote 3 Compressor starting under 3 Check head unloader ('bleeder”) valve system. pressure 2. Motor doesn't hum a. Magnetic starter a1.     Power leads to motor a1.    Check wiring and reconnect as needed. coil clicks disconnected. a2.    Motor burned out a a2.    Replace motor. b. Coil chatters b1.    Voltage to coil too low to b1.    See  Low Voltage Note. On & Oft pull it in c. Coil Does Not Click c1 c1.Overload tripped out c1.    Press 'RESET button on panel front to reset. c2.    Main power disconnected c2 Reconnect or replace fuse. or fuse blown c3.    Pressure switch contacts c3.    Check and free up or replace pressure switch. stuck open c4.    Low oil level switch open, c4.    Check oil level or replace switch. c5.    Defective starter. c5.    Replace starter assembly. COMPRESSOR RUNS AND THEN STOPS 1.Stops shortly after 1 Overload misadjusted 1. Turn white adjustment screw to a higher starting or after number (If applicable). running awhile 2 Compressor overloading 2 Inspect compressor valves and tank valves causing motor overload for carbon build up. a. Stops shortly after a1.    Low voltage causing a1.    See ' Low Voltage Note. a2 Low oil level switch open, a2 Check oil level or replace switch. if installed. motor overload. b. Stops after b1.    Compressor or starter by b1.    Ventilate compressor room area or remove. running awhile overheating starter from compressor and mount on wall. *NOTE:  LOW  VOLTAGE  -  Low  voltage  can  cause  a  multitude  of  problems  The  most  common  cause  of  low  voltage  is when the wire size supplying power to the compressor is too small The longer the run of wire the larger the diameter must be to overcome the inherent voltage loss caused by the wire resistance The supply voltage at the main panel could also be low as supplied by your local power company, or you may have too many other pieces of equipment running off the same line  Your  local  electrician  should  be  contacted  to  evaluate  and  correct  the  problem  according  to  the  National  Electrical Code. 200-2009 (page 3-640)