4-1
SECTION 4
SERVICE
4.1 REMOVING THE REFRIGERANT
NOTE
To avoid damage to the earth’s ozone layer,
use a refrigerant recovery system whenever
removing refrigerant.
To Service any High and Low Side Refrigeration Component:
Store the refrigerant charge in an evacuated
container. Attach hose (line) to liquid line valve to
remove liquid refrigerant.
4.2 REFRIGERANT LEAK CHECKING
a. The recommended procedure for finding leaks in a
system is with a halide torch or electronic leak detector.
Testing joints with soapsuds is satisfactory only for
locating large leaks.
b. If the system is without refrigerant, charge the system
with refrigerant to build up pressure between 2.1 to 3.5
kg/cm
@
(30 to 50 psig). Remove refrigerant drum and leak
check all connections.
NOTE
It must be emphasized that only the correct
refrigerant drum be connected to pressurize the
system. Any other gas or vapor will contaminate
the system which will require additional purging
and evacuation of the high side (discharge) of
the system.
c. Remove refrigerant using a refrigerant recovery
system and repair any leaks.
d. Evacuate and dehydrate the unit. (Refer to section 4.3)
e. Charge unit per section 4.4.
4.3 EVACUATION AND DEHYDRATION
4.3.1 General
Moisture is the deadly enemy of refrigeration
systems. The presence of moisture in a refrigeration
system can have many undesirable effects. The most
common are copper plating, acid sludge formation,
“freezing-up” of metering devices by free water, and
formation of acids, resulting in metal corrosion.
4.3.2 Preparation
a. Evacuate and dehydrate only after pressure leak test.
(Refer to section 4.2.)
b. Essential tools to properly evacuate and dehydrate
any system include a vacuum pump (8 m
@
H = 5 cfm
volume displacement, P/N 07-00176-01) and electronic
vacuum gauge.
c. Keep the ambient temperature above 15.6
_
C (60
_
F)
to speed evaporation of moisture. If ambient
temperature is lower than 15.6
_
C (60
_
F) ice might form
before moisture removal is complete. Heat lamps or
alternate sources of heat may be used to raise the system
temperature.
d. Replace the filter-drier with a section of copper
tubing with the appropiate fittings. This idea will help
speed up the evacuation procedure.
4.3.3 Procedure
1. Refrigerant Recovery Unit
2. Refrigerant Cylinder
3. Evacuation Manifold
4
Valve
5. Vacuum Pump
6. Electronic Vacuum Gauge
7. Liquid Line Valve
8. Condenser Coil
9. Suction Service Valve
10. Compressor
11. Discharge Service Valve
12. Evaporator Coil
1
2
3
4
5
6
7
8
9
10
11
12
4
4
Figure 4-1. Vacuum Pump Connections
a. Remove all refrigerant using a refrigerant recovery
system.
b. The recommended method to evacuate and
dehydrate the system is to connect three evacuation
hoses (Do not use standard service hoses, as they are not
suited for evacuation purposes.) as shown in Figure 4-1
to the vacuum pump and refrigeration unit. Also, as
shown, connect a evacuation manifold, with evacuation
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