CHAPTER III - GENERAL MAINTENANCE SECTION I NORMAL MAINTENANCE SECTION II GENERAL SERVICING 1 - Water System 2 - Refrigeration System 3 - Noise 4 - Continuous Operation SECTION I - NORMAL MAINTENANCE After the water cooler is installed and operating properly, very    little    maintenance    is    required.        No    oiling    is necessary on hermetic units as both compressor and fan motor are permanently oiled.  With open type belt driven units,   oiling   of   the   motor   twice   a   year   is   required. Cleanliness of equipment is most important. The    air    cooled    ;condenser,    located    in    the machine   compartment   of   the   cooler,   requires   periodic inspection.      Any   accumulation   of   lint   or   dust   in   air passages  requires  removal.    Dirty  condensers  can  be cleaned  with  a  non-metallic  brush,  air  hose  or  vacuum cleaner. Periodic   cleaning   of   the   drain   or   precooler   is also  required.    To  clean,  remove  strainer  from  cabinet top, and clean internally with a non-metallic brush. The stainless top is easily cleaned.  Metal polish will restore luster.  The side panels can be washed and polished with a soft cloth. CAUTION  -  FREEZING  TEMPERATURES-   To   prevent serious  damage  to  the  water  cooler,  all  water  must  be drained when cooler is exposed to freezing temperatures. After   the   water   supply   has   been   turned   off, remove  the  remote  plug,  depress  bubbler  valve.    This will  drain  the  tank  type  cooling  unit.    When  the  water regulating   valve   is   mounted   inside   of   the   cabinet,   the entire valve should be disconnected.  This will permit the water to drain from the "Remote" fitting. Water  coolers  with  the  coil-on-coil  type  cooling unit,  can  be  drained  by  blowing  the  water  coil  with  low pressure air. Water  must  also  be  drained  from  water  cooled condensers.        Remove    both    inlet    and    outlet    water connections  from  water  supply  and  blow  the  water  coil with low pressure air. SECTION II - GENERAL SERVICING 1. WATER SYSTEM Rusty  pipes,  sediment  deposits  in  the  water  and  pipe sealing   compound   often   create   problems   in   the   water system    of    the    cooler.        When    these    conditions    are suspected,   flush   the   water   supply   and   install   a   water strainer ahead of cooler. Water  flow  blockage  in  the  water  system  is  first noticable   at   the   bubbler   nozzle.      For   procedures   to correct this problem, see Chapter IV Section II. 2. REFRIGERATION SYSTEM Improper installation of the water cooler, by blocking the entrance   or   discharge   of   condenser   air,   often   creates problems  in  the  refrigeration  system.    Dirt,  lint  and  dust on   the   condenser   fins   can   cause   similar   problems   of erratic   compressor   operation,   warm   outlet   water,   and overload   protector   and/or   starting   relay   failure   on   the compressor. Restricted     air     flow     through     the     condenser causes    abnormally    high    head    pressures    since    heat dissapation  is  reduced.    This  imposes  a  greater  load  on the  compressor  motor  and  may  cause  the  overload  to trip. Similar    conditions    can    arise    with    the    water- cooled  condenser  when  the  water  flow  is  restricted,  or the condenser water metering valve is out of adjustment. To  test  the  efficiency  of  the  condenser,  check  the  inlet and outlet water temperatures with a    thermometer.        The    temperature    difference    should never be more than 250 F. 3. NOISE The   water   cooler   is   normally   free   of   excessive   noise. The  compressor  motor  assembly  is  suspended  on  four springs  within  the  welded  steel  housing.    The  fan  motor mounting  bracket  is  rigidly  secured.    The  fan  blade  is mounted on the fan motor shaft with a rubber washer to minimize  noise  transmission  to  the  cooler.    If  the  fan blade   is   damaged,   it   should   be   replaced   rather   than repaired  or  re-aligned.    The  compressor  or  fan  motor should be replaced if either develops an unusual noise. 4. CONTINUOUS OPERATION The  refrigeration  system  has  been  designed  to  operate on the demands of the thermostat.  If the demands of the thermostat are not met, the unit will continue to operate. This condition can occur if the unit has.... 1 -   Short in the electrical system 2 -   Fused electrical contacts in the thermostat 3 -   Moisture in the system 4 -   Plugged refrigerant strainer 5 -   Undercharge of refrigerant 6 -   A broken discharge tube in the compressor. 9