Fujitsu FO20R Series Installation Instructions Manual page 12

4.0 INSTALLATION
4.4.2.5 Oil Level Adjustment for
Long Line Set Applications
Additional oil will need to be added if refrigerant is
added during installation. The following provides
the equation for the oil level adjustment and the
compressor name plate oil charge for the different
outdoor units.
Oil to be Added = [(Charge Adjustment + OD
Unit Name Plate Refrigerant Charge (oz.)) ×
(0.022) – [(0.10) × (Compressor Name Plate Oil
Charge (oz.))]
Example: An application requires 125 ft of line set
with a liquid line diameter of 3/8", Charge Adjust-
ment = 66 oz., Name Plate Charge = 212 oz.,
Name Plate Oil Charge = 40 oz., Oil to be Added =
4.4.3 Line Set Length and Fitting Losses
Refrigerant tubing is measured in terms of actual
length and equivalent length. Actual length is used
for refrigerant charge applications. Equivalent
length takes into account pressure losses from tub-
12
((66 oz. + 212 oz.) × .022) – (.10 × 40 oz.) = 2 oz.
4.4.2.6 Capacity Losses
Long line lengths can result in a reduction in capac-
ity due to vapor line pressure drop and heat gain or
loss. Refer to Table 2 for capacity loss multipliers
for various vapor line diameters and equipment line
lengths. This table does not account for any capac-
ity loss due to heat gain or loss from the environ-
ment. It is extremely important not to oversize the
vapor line to minimize capacity loss at the expense
of proper oil return. If the table shows an "NR" for
a particular vapor line diameter and length, or, if a
vapor line diameter is not listed, oil return will not be
adequate.
ent commonly used equivalent lengths.
Table 1
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