CHAPTER VI - MISCELLANEOUS COOLERS SECTION I COMPARTMENT WATER COOLERS 1 - Explanation of the Bottle - Comportment Refrigeration System 2 - Explanation of the Pressure- Comportment Refrigeration System 3 - Maintenance 4 - Service and Trouble Shooting SECTION II EXPLOSION PROOF WATER COOLERS SECTION III BELT DRIVEN OR OPEN TYPE REFRIGERATION SYSTEM WATER COOLERS 1 - Explanation 2 - Maintenance SECTION I - COMPARTMENT WATER COOLERS SCHEMATIC -REFRIGERATION COMPARTMENT-BOTTLE WATER COOLER 1. EXPLANATION OF THE BOTTLE - COMPARTMENT REFRIGERATION SYSTEM The  high  pressure  liquid  refrigerant  passes  through  the capillary tube to the water evaporator.  Upon leaving the water   evaporator,   it   travels   through   a   weight   check valve,  which  prevents  freezing  of  the  water  system,  to the  compartment  evaporator.    After  circulating  through the    compartment    coil,    the    refrigerant    then    passes through  the  accumulator  and  back  to  the  compressor. The   system   is   controlled   by   one   thermostat   whose power element is strategically located on the side of the compartment   evaporator.      When   the   water   demands more  cooling,  the  warmer  refrigerant  vapor  passes  from the  water  evaporator  through  the  weight  check  valve  to the   compartment   evaporator.      This   in   turn   warms   the power element of the thermostat causing the compressor to start, regardless of the temperature of the compartment.    The  compressor  will  also  start  when  the compartment requests cooling and the water temperature is correct. 2. EXPLANATION OF THE PRESSURE - COMPARTMENT REFRIGERATION SYSTEM Early    designs    of    the    compartment,    pressure    water system   use   a   solenoid   valve   in   the   water   evaporator outlet  controlled  by  a  thermostat  to  prevent  freezing  of the  water  cooling  system.    A  capillary  tube  branching from   a   specific   turn   of   the   water   evaporator   supplies refrigerant   for   cooling   of   the   compartment   evaporator. When  the  water  requires  more  cooling,  the  thermostat contacts close causing the  solenoid  valve  to  open  and  the  compressor  to  start. When  the  compartment  only  requires  more  cooling,  its thermostat   contacts   close   causing   the   compressor   to start. Later   models   use   two   refrigeration   systems, each   operating   independently   of   one   another.      Each system has its own controlling thermostat to operate and control its system. Both  refrigeration  systems  share  a  common  air cooled double circuited condenser and use one fan. A   relay   is   employed   to   actuate   the   fan   when either system starts. WIRING DIAGRAM FOR  COMPARTMENT PRESSURE WATER  COOLER 3. MAINTENANCE An occasional defrosting of the compartment evaporator is   the   only   difference   for   general   maintenance   of   the cooler.  When defrosting of the compartment is required, disconnect  electrical  power  supply.    Remove  ice  cube trays  and  place  a  pan  of  hot  water  in  the  compartment. The door can remain open.  Defrosting requires about 15 minutes    depending    upon    the    frost    build-up.        When completed, fill the ice trays with fresh water and connect the electrical supply. 4. SERVICING AND TROUBLE SHOOTING When    trouble    is    encountered    with    the    compartment water  coolers,  service  procedures  mentioned  earlier  in this manual should be followed. 15