Thermo King SB-190 30, Manual

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65
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.
COMPRESSOR
Removal
1. Pump down the low side and equalize the pressure to
slightly positive.
2. Loosen the compressor belts on Model 50 units.
3. Front seat the discharge and suction service valves.
4. Recover the refrigerant remaining in the compressor.
5. Unbolt the discharge and suction service valves from
the compressor.
6. Disconnect the high pressure cutout switch, the pilot
solenoid line, and remove the compressor oil filter.
7. Support the compressor and remove the compressor
mounting bolts from the flywheel housing.
8. Lift the service valves out of the way.
9. Slide the compressor to the left until the coupling pins
are clear, and remove the compressor belts from Model
50 units.
10. Remove the compressor from the front of the unit.
Keep the compressor ports covered to prevent dust,
dirt, etc., from falling into the compressor.
NOTE: When the compressor is removed from the
unit, the oil level should be noted, or the oil removed
from the compressor should be measured so that the
same amount of oil can be added before placing the
replacement compressor in the unit.
Installation
1. Slide the compressor into the unit.
2. Place the compressor in position, install the compressor
belts on Model 50 units, and install the mounting bolts.
NOTE: The compressor drive coupling or clutch will
only slide onto the coupling pins in either of two posi-
tions, which are 180 degrees apart.
3. Install the service valves using new gaskets soaked in
compressor oil. Connect the high pressure cutout
switch, the pilot solenoid valve line, and install the
compressor oil filter.
4. Pressurize the compressor and test for refrigerant leaks.
5. If no leaks are found, evacuate the compressor.
6. Back seat the suction and discharge service valves.
7. Tighten the compressor belts on Model 50 units.
8. Operate the unit at least 30 minutes and then inspect the
oil level in the compressor. Add or remove oil if neces-
sary.
9. Check the refrigerant charge and add refrigerant if
needed.