CRR-20 & CRR-40, September 1999
Refrigeration Maintenance and Service Operations
Compressor Replacement
6-17
Compressor Replacement
Removal
1.
Remove the compressor compartment bracket. Close the
liquid line service valve and pump down the low side to -
35 kPa, -0.35 bar, 10 in. vacuum. Break the vacuum with
nitrogen between 10 and 20 kPa, 0.10 and 0.20 bar, 1 and
3 psig.
NOTE: If the compressor does not operate, or
the compressor is unable to pump the low side
down, the refrigerant charge must be reclaimed
before service can be performed on the refrigera-
tion system.
2.
Front seat the discharge valve.
CAUTION: Any time the discharge valve is front
seated, disconnect the unit power source to pre-
vent accidental compressor start-up.
3.
Remove discharge service valve, suction service valve,
and liquid injection line from the compressor.
4.
Disconnect the wire connector for the high pressure cutout
switch, condenser pressure switch, and compressor dis-
charge temperature sensor.
5.
Remove the three-phase electric power connection.
6.
Remove the compressor mounting tray bolts and nuts.
7.
Slide the compressor from the unit.
8.
Keep the compressor ports covered to prevent dust, dirt,
etc., from falling into the compressor.
NOTE: When the compressor is removed from
the unit, oil level should be noted or the oil
removed from the compressor should be mea-
sured so that the same amount of oil can be
added before placing the new compressor or
repaired compressor in the unit.
Installation
1.
Slide the compressor into the unit. Install mounting bolts,
washers and nuts, and tighten.
2.
Bolt the discharge valve to the compressor with a new
gasket lightly coated with compressor oil. Bolt the suc-
tion service valve to the compressor using a new O-ring
coated with compressor oil.
3.
Apply refrigerant locktite to the threads of the switches.
Install the switches. Connect the wire connectors for the
condenser fan pressure switch, high pressure cutout
switch, and compressor discharge temperature sensor.
4.
Connect liquid injection line to compressor body.
5.
Connect three-phase electric power to the compressor.
6.
Pressurize the compressor with refrigerant gas (same gas
as that used in the system). Check for refrigerant leaks
around the compressor assembly and gasket connections.
7.
If no leaks are found, recover the refrigerant used for the
leak test (see “Refrigerant Recovery” in this chapter).
Because this refrigerant gas will contain some air, place it
in a contaminated refrigerant bottle to be reclaimed later.
8.
After all pressure is removed from the low side and com-
pressor, hook up your evacuation equipment.
9.
Evacuate the low side and compressor (see “Evacuation
and Cleanup of the Refrigeration System” in this chapter).
10. Back seat the discharge service valve and open the liquid
line service valve fully.
11. Operate the unit at least thirty minutes and then inspect
the oil level in the compressor. Add or remove oil if nec-
essary.
12. Check the refrigerant charge and add refrigerant if needed.
Содержание CRR-20
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