Rheem RA17 Series, Installation Instructions Manual

Page: 13 / 56

13
Tubing
INSTALLATION
Interconnecting Tubing (cont.)
Suction Line Selection
Purpose of the suction line is to return superheated
vapor to the condensing unit from the evaporator.
Proper suction line sizing is important because it
plays an important role in returning oil to the com-
pressor to prevent potential damage to the bear-
ings, valves, and scroll sets. Also, an improperly
sized suction line can dramatically reduce capacity
and performance of the system. The procedure for
selecting the proper suction line is as follows:
• The total amount of suction line needed
• Add all of the equivalent lengths associated with
any ttings or accessories using the table on
previous page.
• Add the total length and tting pressure drop.
This will equal your total equivalent length.
• eference Table 2 to verify that the calculated
equivalent length falls within the compatibility
region of the chart.
• erify Table 3 to verify the capacity di erence is
compatible with the application.
Refrigerant Migration During
Off Cycle
Long line set applications can require a consider-
able amount of additional refrigerant. This addition-
al refrigerant needs to be managed throughout the
entire ambient operating envelope that the system
will go through during its life cycle. - ycle mi -
gration is where excess refrigerant condenses and
migrates to the lowest part of the system. Exces-
sive build-up of refrigerant at the compressor will
result in poor reliability and noisy operation during
startup. This section demonstrates the required
accessories and unit con guration for di erent ap -
plications.
OUTDOOR UNIT LEVEL OR NEAR LEVEL TO INDOOR SECTION LINE SET
LIQUID LINE.
ST-A1219-01-01
IDEALLY, LINE SET SLOPES AWAY
FROM OUTDOOR. VERIFY
SUB-COOLING PRIOR TO
THROTTLEING DEVICE, INSULATED
REFERENCE TABLE 2 FOR
MAXIMUM LENGTH LIMITATIONS