Thermo King MD-MT, Operator'S Manual

Page: 157 / 192

157
Remote Evaporator Refrigeration Service
Operations
NOTE: It is generally good practice to replace
the filter drier whenever the high side is opened
or when the low side is opened for an extended
period of time.
Expansion Valve Assembly
Removal
1. Pump down the low side and equalize the
pressure to slightly positive. Remove the
evaporator access panels.
2. Disconnect the liquid inlet line and distributor
from the expansion valve.
3. Remove the feeler bulb from the clamp. Note
the position of the feeler bulb on the suction
line.
4. Disconnect the equalizer line.
5. Remove the mounting U-bolt.
6. Remove the expansion valve assembly from
the unit.
Installation
1. Place the expansion valve in the unit and
install the mounting U-bolt.
2. Connect the equalizer line to the expansion
valve.
3. Connect the liquid inlet line and distributor to
the expansion valve.
4. Clean the suction line to a bright polished
condition. Install the feeler bulb clamps and
feeler bulb on the side of the suction line in its
former position. The feeler bulb must make
good contact with the suction line or the
operation will be faulty. Wrap it with
insulating tape.
5. Pressurize the low side and test for leaks. If no
leaks are found, evacuate the low side.
6. Install the access panels.
7. Open the refrigeration valves and place the
unit in operation.
8. Test the unit to see that the expansion valve is
properly installed.
Evaporator Coil
Removal
1. Remove refrigerant by approved methods.
2. Remove evaporator assembly.
3. Remove the access panels.
4. Disconnect the distributor from the expansion
valve.
5. Remove the insulating tape and feeler bulb
from the suction line. Note the position of the
feeler bulb on the suction line. Disconnect the
equalizer line from the suction line.
6. Heat and unsolder the suction line connection
to the evaporator coil.
7. Remove the mounting bolts and slide the coil
from the housing.
Installation
1. Place the evaporator coil in the evaporator
housing and install the mounting bolts.
2. Clean and solder the suction line connections
to the evaporator coil.
3. Connect the distributor to the expansion valve.
4. Clean the suction line to a bright polished
condition. Install the feeler bulb clamps and
the feeler bulb on the suction line. Locate the
bulb on the side of the suction line in its
former position. The feeler bulb must make
good contact with the suction line or the
operation will be faulty. Wrap it with
insulating tape.
5. Connect the equalizer line to the suction line.
6. Pressurize the low side and test for leaks. If no
leaks are found, evacuate the low side.
7. Install the access panels.
8. Install evaporator assembly. Leak test,
evacuate and charge the unit.