Trane R Series Installation Operation & Maintenance page 56

56
Installation - Remote Condenser
Oil Charge Determination
The RTUA unit is factory charged with the amount of oil required by the
system, without the field-installed piping. The amount of additional oil
required is dependent upon the amount of refrigerant that is added to the
system for the field installed piping.
Calculate the amount of oil to be added, using the following formula:
Pints of Oil (Trane OIL -31) = for field-installed piping
Example
Shown in Figure 26 are RTUA 80 ton and RTCA 80 ton units designed for a
leaving evaporator water temperature of 42 degrees F . This example will
show how to calculate the pipe sizes for both the liquid and discharge lines.
The discharge line consists of one long radius elbow and 4 short radius
elbows. The liquid line also consists of one long radius elbow and 4 short
radius elbows.
Discharge Line
Actual length of horizontal
or downflow lines
Actual length of upflow lines
Total equivalent length
Approx. line size for horizontal/downflow lines
(Table 12)
Approx. line size for upflow lines
(Table 13)
Equiv. length of one long radius elbow at 21/8"
(Table 7)
Equiv. length of 4 short radius elbows at 2 1/8"
(Table 7)
Total equivalent length
New line size for horizontal/downflow and upflow
lines remains
(Table 12
ALL DISCHARGE LINE SIZES ARE
Liquid Lines
Actual length of horizontal or downflow lines
Actual length of upflow lines
Total equivalent length
Approx. line size for horizontal/downflow lines
(Table 8)
Approx. line size for upflow lines
(Table 8)
Equiv. length of one long radius elbow at 1 1/8"
(Table 7)
Equiv. length of 4 short radius elbows at 1 1/8"
Table 7)
Total equivalent length
Lbs. of R-22 added
100
= 2 + 5 + 71 = 78 ft.
= 15 1/2 + 5 = 20 1/2 ft.
= 1 1/2 x (78 + 20 1/2) = 147 .75
= 2 1/8"
= 2 1/8"
= 3 2/5 ft.
= 4 x 5 1/5 ft. = 20 4/5 ft.
= 78 + 20 1/2 + 3 2/5 + 20 4/5 = 122.7 ft.
= 2 1/8"
= 2 1/8"
= 8 + 75 + 20 = 103 ft.
= 8 ft.
= 1 1/2 X (103 + 8) =166 1/2 ft.
= 1 1/8"
= 1 3/8 ft.
= 1 9/10
= 4 x 2 7/10 ft. =10 4/5 ft.
= 103 + 8 + 19/10 + 10 2/5 =123 7/10 ft.
RLC-SVX07A-EN