Thermo King 098916, Maintenance Manual

Page: 147 / 196

Refrigeration Maintenance
146
Economizer Expansion Valve
Replacement
Economizer Expansion Valve Removal
Remove the economizer expansion valve by
performing the following steps:
1. Recover the refrigerant charge from the unit
(see “Recovering Refrigerant from the
System” on page 137).
2. Unclamp feeler bulb from the suction line in
the condenser section.
3. Heat and unsolder the inlet and outlet lines
from economizer expansion valve.unit.
4. Remove economizer expansion valve from
unit.
Economizer Expansion Valve Installation
1. Install the economizer expansion valve by
performing the following steps:
2. Clean the inlet and outlet lines for soldering.
3. Place new economizer expansion valve in
position.
4. Solder inlet and outlet line connections to
economizer expansion valve.
NOTE: Thermo King strongly recommends
that dry nitrogen be used to purge the system
during any solder operations (see “Using
Pressurized Nitrogen” in this chapter).
5. Pressurize the refrigeration system and check
for leaks (see “Refrigerant Leak Test
Procedure” in this chapter).
6. If no leaks are found, recover the refrigerant
used for the leak test (see “Recovering
Refrigerant from the System” on page 137).
7. Evacuate the system (see “Evacuation and
Cleanup of the Refrigeration System” in this
chapter).
8. Locate feeler bulb in former position. The
feeler bulb must make good contact or
operation will be faulty. Cover with insulating
tape.
9. Recharge the unit with R-404A (see
“Charging the System with Refrigerant” in
this chapter).
10. Perform a controller pretrip test to verify
system operation and correct feeler bulb
installation.
1. Liquid Line
2. Liquid Line
3. Suction Line
4. Unbolt Heat Exchanger Behind Bracket
5. Suction Line
Figure 93: Economizer Heat Exchanger (Before
January 2003)
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2
3
4
5
1. Economizer Heat Exchanger
2. Economizer Expansion Valve
3. Vapor Injection Line
4. Feeler Bulb Line
Figure 94: Economizer Expansion Valve and Heat
Exchanger (After January 2003)
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3
1
4
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