Thermo King 098203, Руководство по обслуживанию

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Refrigeration Maintenance
183
4. Connect the evacuation station and refrigerant tank with gauge manifold (optional) to the unit as
indicated in figure Figure 159 on page 180. Connect evacuation hoses to the compressor suction and
discharge service fittings.
5. Open Evacuation Station valves (V1, V3, and V4). It is only necessary to open valve V2 when a
reading on the micron meter is desired. This is especially true when starting to evacuate a unit and
large amounts of moisture and oil will be passing by the sensor.
6. Open the vacuum pump Iso-Valve™ built into the pump housing below the handle. It is recommended
that the valve be kept open at all times.
7. If connecting a refrigerant tank and gauge manifold to the evacuation station, close the gauge
manifold and refrigerant tank valves to prevent refrigerant from being drawn from the tank.
Unit Evacuation
1. Turn on the vacuum pump. Open the gas ballast valve located on top of the pump housing behind the
handle (the valve is fully open at two turns counterclockwise). Evacuate the system to 500 microns to
achieve a final equilibrium pressure of 2000 microns or less. The final equilibrium pressure is
determined with the Thermo King Evacuation Station using the following procedure (called a
pressure rise test):
a. Evacuate the system using the evacuation station until the vacuum level reaches 1000 microns.
Then close the gas ballast valve.
b. Continue evacuation to 500 microns or until vacuum stabilizes at its lowest level. Contamination
may delay reaching the lowest level for a period of several hours or more.
c. Close valve V1 to isolate the vacuum pump from the system.
d. Observe the vacuum level on the micron meter.
When the meter has stabilized, the value indicated on the micron meter is the equilibrium pressure. This
reading must be 2000 microns or less.
NOTE: The presence of refrigerant in the compressor oil may prevent a low vacuum reading from
being achieved. Compressor oil can continue to outgas for long periods of time.
2. If the vacuum level appears to stall above 500 microns, back seat the discharge service valve and
observe the micron meter.
• A drop in pressure indicates that the compressor oil is out-gassing and further evacuation is
necessary.
• An increase in pressure indicates that a leak exists or there is moisture in the system. Perform a
pressure rise test and evaluate.
3. Close valve V1 when the desired vacuum level has been reached.
4. Wait five minutes and read the micron meter.
• A system that is leak free and dry will remain below 2000 microns for 5 minutes.
• A system that rises above 2000 microns but stabilizes below atmospheric pressure is probably
contaminated with moisture or has refrigerant out-gassing from the compressor oil. Additional
evacuation is required.
• A system that continues to rise without stabilizing has a leak and must be repaired.
5. If the vacuum level remained below 2000 microns for 5 minutes, the unit is ready to charge. See
“Charging the System with Refrigerant”.