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Sealed System
Evacuating the System
To achieve the required levels of evacuation, a properly
maintained two stage vacuum pump in good condition
is required. It is absolutely essential to maintain your
vacuum pump according to the manufacturer's
instructions, including required oil changes at the
recommended intervals. Vacuum pump oil should
always be changed after evacuating a contaminated sys-
tem. Vacuum pump performance should be checked
periodically with a micron gauge.
1.
Ensuring that the valve on the charging cylinder is
closed, start the vacuum pump. Slowly open both
manifold valves, counterclockwise, for two full turns.
If high vacuum equipment is used, just crack both
manifold valves for a few minutes and then open
slowly for the two full turns counterclockwise.
This will prevent the compressor oil from foaming
and being drawn into the vacuum pump.
EEV
Va lve
Hot Tube
Cap Tube
Ice Ma ker
Ev aporator
Filter Drie r
Condenser
Figure 7-21. Installation of Recovery Equipment Dispenser with Refrigerated Finger Ice Maker
2.
3.
4.
5.
6.
Ev aporator
Ice Ma ker
Accumulato r
Cap Tube
Fr eez er
Fr eez er
Ev aporator
Ev aporator
Proces s
Tube
Adapter s
Compresso r
7-22
Operate vacuum pump for 30 minutes to a minimum
of 29.5 inches of vacuum or until a vacuum of 600
microns is obtained.
Close the manifold valve connected to the vacuum
pump. Watch the compound gauge for several
minutes. If the reading rises, there is a leak in the
system, go to step 4. If no leak is indicated, stop the
vacuum pump. The system is now ready for
charging.
If a leak is indicated, stop the vacuum pump and
introduce a small charge of refrigerant into the
system by cracking the valve on the bottom of the
charging cylinder until the system is pressurized to
40 or 50 lbs. P.S.I.
Leak test the low side. Run the compressor for
a few minutes and leak test the high side. When
leak is found, connect refrigerant recovery system.
Turn on recovery system, open the line tap valve,
and allow refrigerant to flow into an approved tank.
Repair and go back to step 1.
See page 7-25 Refrigerant Leaks for instructions on
heating the compressor crankcase on products that
have ran with a low side leak.
Compound
Gaug e
Gaug e
Manifold
Hand Shutof f
Va lve
2 Stag e
Va cuum Pum p
Pressure
Gaug e
T-Fitting
Heated
Char ging
Cylinder
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