39
Desert Aire - LC/LV Manual
•
Purge all hoses and equipment of non-condensable gasses before connecting to the
sealed
system.
•
Use only original equipment parts or factory approved equivalent for servicing.
•
Use required refrigerant system oil.
•
Minimize the time the system is open to atmosphere while servicing. Cap all
connections when there is no active service work on the system. This is particularly
important with units that contain POE oils as moisture will be absorbed quickly and
cannot be removed with a vacuum.
•
Never open the system while under a vacuum. Should the system require opening to
repair a leak or other service when in a vacuum, fill with dry nitrogen to atmospheric
pressure before opening.
•
Have a Schrader core replacement tool available when servicing the refrigeration
system. Although rare, defective or damaged Schrader valve cores can contribute to
refrigerant
loss.
•
Charge systems only by weight after servicing. Review the rating plate and any field
charge
labels.
•
When servicing, additional liquid line filter dryers and suction filters may be required.
This does not apply to installation of remote condensers.
•
Charge refrigerant blends, including R-410A and R-407C, with liquid only. Charging
should be done into the high side of the system whenever possible. Refer to section
5.5 for additional procedures related to charging.
Note that the superheat should be stable and within 4 degrees of fluctuation. Minimum value
for superheat at compressor in all modes:
30.0 - 40.0
40.1 - 50.0
50.1 - 60.0
60.1 - 70.0
70.1 - 80.0
60.0 - 65.0
12
13
13
14
14
Superheat Minimum Values Chart Temp (°F)
65.1 - 70.0
13
14
14
15
15
70.1 - 75.0
14
15
15
15
16
80.1 - 85.0
15
16
18
18
19
75.1 - 80.0
15
15
16
16
18
85.1 - 90.0
16
18
18
19
20
Relative
Air
Humidity (%RH)
Relative Air
Temperature (°F)
Figure 27 - Superheat Minimum Values Chart
