Outdoor Unit | Installation Manual |
8 EVACUATE AND DEHYDRATE THE SYSTEM
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or improper operation.
Never use the system compressor as a vacuum pump.
5.Evacuate using either deep vacuum or triple evacuation method.
6.After evacuation is complete, fully close the low side of manifold gage and stop operation of vacuum pump.
Refrigerant tubes and indoor heat exchanger should be evacuated using the recommended deep vacuum method of 500 microns. The alternate triple evacuation method may be used if the procedure outlined below is followed. Always break a vacuum with dry nitrogen.
SYSTEM VACUUM AND CHARGE
Using Vacuum Pump
1.Completely tighten flare nuts A, B, C, D, connect manifold gage charge hose to a charge port of the low side service valve.
Service Valve
Outdoor Unit |
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| Refrigerant |
| Indoor Unit | ||||
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| A | Low Side |
| C |
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| B | High Side |
| D |
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Service Valve |
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Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of pulling a vacuum of 500 microns and a vacuum gage capable of accurately measuring this vacuum depth. The deep vacuum method is the most positive way of assuring a system is free of air and liquid water.
Deep Vacuum Graph
| 5000 |
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| 4500 |
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| 4000 |
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| 3500 |
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| LEAK IN |
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MICRONS |
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3000 |
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2500 |
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2000 |
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1500 |
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| TOO WET | |
| 1000 |
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| 500 |
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| TIGHT DRY | |
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| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
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| MINUTES |
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2.Connect charge hose to vacuum pump.
3.Fully open the low side of manifold gage.
Manifold | Manifold Gage |
500 microns
Low side valve
High side valve
Charge hose
Charge hose
Vacuum pump
Packed valve at gas side
Charge port
(Valve core (Setting pin))
4. Start vacuum pump.
Triple Evacuation Method
The triple evacuation method should only be used when vacuum pump is only capable of pumping down to 28 in. of mercury vacuum and system does not contain any liquid water.
Refer to “Triple Evacuation Method chart” and proceed as follows:
1.Pump system down to 28 in. of mercury and allow pump to continue operating for an additional 15 minutes.
2.Close service valves and shut off vacuum pump.
3.Connect a nitrogen cylinder and regulator to system and open until system pressure is 2 psig.
4.Close service valve and allow system to stand for 1 hr. During this time, dry nitrogen will be able to diffuse throughout the system absorbing moisture.
5.Repeat this procedure as indicated in the chart. System will then be free of any cotaminants and water vapor.
– 15 – |
