Refrigeration Maintenance and Service Operations
146
Filter Drier/In-line Filter
Replacement
Removal
1. Recover the refrigerant charge from the unit
(see “Refrigerant Recovery” in this chapter).
2. Place the new filter drier near the unit for
immediate installation.
3. Using two wrenches, “crack” both the inlet
and outlet nuts on the filter drier. Use two
wrenches on flare fittings to prevent line
damage.
4. Separate the filter drier line mountings.
5. Remove the filter bracket clamping nuts and
bolts.
6. Remove the old filter drier from the unit.
Installation
1. Remove the sealing caps from the new filter
drier.
2. Apply clean compressor oil to filter drier
threads.
3. Install new filter drier in unit. Finger tighten
mounting nuts.
NOTE: To prevent incorrect installation of
the dehydrator, the inlet and outlet fittings
are different sizes.
4. Reinstall clamping brackets, nut and bolts.
Tighten the bolts.
5. Tighten filter drier inlet and outlet nuts.
NOTE: Always hold the body of the
dehydrator (or liquid filter) near the flange
fittings to prevent twisting the tubing when
the nuts are being loosened or tightened.
6. Pressurize the refrigeration system and check
for leaks (see “Refrigerant Leak Test
Procedure” in this chapter).
7. If no leaks are found, recover the refrigerant
used for the leak test (see “Refrigerant
Recovery” in this chapter).
8. Evacuate the system (see “Evacuation and
Cleanup of the Refrigeration System” in this
chapter).
9. Recharge the unit with R-404A (see
“Charging the System with Refrigerant” in
this chapter).
10. Perform a controller pre-trip test to verify
system operation.
Expansion Valve Replacement
NOTE: Because the feeler bulb is located in the
evaporator section, complete replacement of the
expansion valve can only be performed on an
empty container. If the expansion valve fails on a
loaded container, temporarily locate the feeler
bulb on the suction line in the condenser section.
Locate the feeler bulb as close to the evaporator
section as possible. Remove the insulating tape
from the suction line. Clamp the feeler bulb on
the suction line. Then completely cover the feeler
bulb and suction line with insulating tape.
Removal
1. Recover the refrigerant charge from the unit
(see “Refrigerant Recovery” in this chapter).
2. Remove insulating tape and unclamp feeler
bulb from the suction line in the condenser
section. Note the position of the feeler bulb on
the side of the suction line.
3. Remove insulating tape from expansion valve
outlet line.
4. Heat and unsolder the equalizer line from
expansion valve.
5. Heat and unsolder the liquid line inlet and
outlet connections to expansion valve in
condenser section.
6. Remove expansion valve from unit.
Installation
1. Clean the liquid lines and equalizer lines for
soldering.
2. Place new expansion valve in position in
liquid line.
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