Amana GSH13018 Service Instructions Manual page 50

SERVICING
REFRIGERANT LINE LENGTH (Ft)
Cond 0-24
Unit
Tons Suct Liq
1 1/2 5/8 1/4
2 5/8 1/4
2 1/2 3/4 3/8
3 3/4 3/8
3 1/2 3/4 3/8
4 7/8 3/8
5 7/8 3/8
*7/8" required for full ratings
**1 1/8" required for full ratings
***Lines greater than 74 feet in length or vertical elevation changes more than 50 feet, refer to the long
line set.
TABLE 8. CAPACITY MULTIPLIERS AS A FUNCTION OF
SUCTION LINE SIZE & EQUIVALENT LENGTH
Nominal Vapor line
capacity diameter
Btuh (in.)
50
18,000 3/4
.99
24,000 3/4 1
30,000 3/4 .98
3/4 .93
36,000
7/8 .98
3/4
.93
42,000
7/8 .97
1-1/8 1
3/4
.90
48,000
7/8 .96
1-1/8
1
7/8 .93
60,000
1-1/8 .99
NOTE: For a condenser with a liquid valve tube connection
less than 3/8" diameter, use 3/8" liquid line tubing for a line
set greater than 25 feet.
TABLE 9. LOSSES FROM SUCTION LINE ELBOWS
(EQUIVALENT LENGTH, FT.)
Type of elbow fitting
90° short radius
90° long radius
45°
Installation Requirements
1. In a completely horizontal installation with a long line set
where the evaporator is at the same altitude as (or slightly
below) the condenser, the line set should be sloped
towards the evaporator. This helps reduce refrigerant
migration to the condenser during a system's off-cycle.
50
25-49 50-74***
Line Diameter (In. OD)
Suct Liq Suct
3/4 3/8 3/4
3/4 3/8 3/4
3/4* 3/8 7/8
3/4** 3/8 7/8**
7/8** 3/8 1 1/8
1 1/8 3/8 1 1/8
1 1/8 3/8 1 1/8
EQUIVALENT LINE LENGTH (FT)
75 100 125
.97 .96 .95
.99 .99 .98
.97 .96 .95
.90 .86 .83
.96 .94 .92
.90 .87 .83
.96 .94 .93
1 .99 .99
.86 .82 .78
.94 .93 .91
1 .99 .99
.91 .89 .86
.98 .98 .97
Table 8
I.D. (in.)
3/4 7/8 1-1/8
1.7 2 2.3
1.5 1.7 1.6
0.7 0.8 1
Table 9
2. For a system installation where the evaporator is above
the condenser, an inverted vapor line trap should be
installed on the suction line just before the inlet to the
evaporator (see Fig 6). The top of the inverted loop must
Liq
be slightly above the top of the evaporator coil and can be
3/8
created simply by brazing two 90° long radius elbows
3/8
together, if a bending tool is unavailable. Properly support
3/8
3/8 and secure the inverted loop to the nearest point on the
3/8
indoor unit or adjacent structure.
3/8
3/8
Fig 6. Evaporator unit with inverted vapor loop
3. An oil trap is required at the evaporator only if the
150
condenser is above the evaporator. Preformed oil
.95
.97
traps are available at most HVAC supply houses, or oil
.94
traps may be created by brazing tubing elbows together
.79
.90
(see diagram below). Remember to add the equivalent
.80
length from oil traps to the equivalent length calculation of
.92
the suction line. For example, if you construct an oil trap
.98
N/R
using two 45° elbows, one short and one long 90° elbow
.89
in a ¾" diameter suction line, the additional equivalent
.98
.84
length would be 0.7+ 0.7+1.7+1.5, which equals 4.6 feet
.97
(refer to table 9).
O il Trap Construction
Long Radius Street Ell
45 °
Ell
45°
Street
Ell
Short Radius
Street Ell
Fig 7. Oil Trap