Commercial Air Conditioner
Model: heat pump, 10SEER UNITS
19
undesirable heat transfer resulting in capacity loss and increased power consumption.
Refrigerant Line Sizing
Check the following table (
Table 8-1
) for correct suction and liquid line sizes for any
combination of the unit size and the maximum refrigerant line length.
Refrigerant Line Sizing
Refrigerant Line Length (Ft)
0 – 24
25 – 49
50 – 74
Line Outside Diameter (In)
Unit Size
(Ton)
Suction Liquid Suction Liquid Suction Liquid
1.5 5/8 3/8
3
/
4
3/8
3
/
4
3
/
8
2.0 5/8 3/8
3
/
4
3/8
3
/
4
3
/
8
2.5 3/4 3/8 3/4 3/8
7
/
8
1
/
2
3.0 7/8 3/8
11
/8 3/8
11
/8
1
/
2
3.5 7/8 3/8
11
/8 3/8
11
/8
1
/
2
4.0 7/8 3/8
11
/8 3/8
11
/8
1
/
2
5.0 7/8 3/8
11
/8 3/8
11
/8
1
/
2
Table 8-1
The factory charge is sufficient for 25 feet of standard liquid line. For longer or shorter liquid line
lengths, adjust the charge as follows:
1/4" Line +/- 0.3 oz. Per foot
5/16" Line +/- 0.4 oz. Per foot
3/8" Line +/- 0.6 oz. Per foot
1/2" Line +/- 1.2 oz. Per foot.
Vertical Separation between Indoor and Outdoor Units
Maximum allowable vertical separations between indoor and outdoor units are illustrated in
Fig. 8-2-A and Fig. 8-2-B
. It's 70' when the indoor unit is below the outdoor unit (Fig.8-3-A),
and 50' when the indoor unit is above the outdoor unit (Fig. 8-2-B).
To ensure good oil return to the compressor when the indoor unit is below the outdoor unit,
suction line oil trap should be used as illustrated in Fig. 8-2-A.
Tubing Connections
! CAUTION
- Use extreme caution in removing the caps from the suction and liquid line
fittings, as there is pressure present. A fitting is on the liquid line to remove pressure.
! CAUTION
- Condensing units are charged with refrigerant. Condensing unit liquid and
suction valves are closed to contain the charge within the unit. Do not force the valve stem
against the retaining ring. If the valve stem is backed out past the retaining ring, system
pressure could force the valve stem out of the valve body and possibly cause personal
injury.
Instructions on the field tubing connections and valve opening procedure are as follow:
1.Tubing should be cut square. Make sure it is round and free of burrs at the connecting ends.
Clean the tubing to prevent contamination from entering the system.
2.Make sure that both refrigerant shutoff valves at the outdoor unit are closed.
