Page 8
IM 818
Refrigerant Tubing
Tubing Length & Elevation
Co
p
per tubing to connect the indoor and outdoor units is sup-
plied by others or it can be ordered from the factory. See
Table 1 for requirements.
Table 1: Refrigeration Tubing Requirements
Note: The refrigerant pre-charged in the outdoor unit is for tubing length "L" up
to 25 ft. See "Installation Diagram" page 5. See Table 6 on page 17 for addi-
tional R-22 refrigerant required on longer runs.
Tubing Preparation
•
Do not use contaminated or damaged copper tubing. Do
not remove plastic, rubber plugs or brass nuts from the
valves, fittings, tubings and coils until you are ready to
connect suction or liquid line into valves or fittings.
•
If any brazing work is required, ensure that the nitrogen
gas is passed through coil and joints while the brazing
work is done. This will eliminate soot formation on the
inside wall of the copper tubing.
•
Cut the copper tubing with a tube cutter (See Figure 10).
•
Remove burrs from cut ends by holding tubing down-
wards to prevent metal chips from entering the tubing.
•
Slide flare nut on tubing.
•
Flare the tubing as shown in Figure 10, Figure 11 and
Table 2.
•
The flare must be even and not cracked or scratched.
Figure 10. Cutting and Flaring Tube
Table 2: Tube Flaring Dimensions
Tubing Connection To Units
•
Connect the copper tubing to both the indoor and outdoor
units (See Figure 11).
•
Torque each flare nut to specifications (See Table 3).
•
Cover both tubes individually with 3/8" minimum wall
thickness foam insulation.
Table 3: Flare Nut Torque Specifications
Figure 11: Flare Tubing Connection
Model Indoor
MCK20A MCK25A MCK30A MCK40A MCK50A
Model Outdoor
MLC20B MLC25B MLC30C MLC40C MLC50C
Max. Length, "L"- Ft.
49’
49’
115’
115’
115’
Max. elevation-Ft.
26’
26’
49’
49’
49’
Max. no. of bends
10
10
10
10
10
Liq. tube size - OD
1/4"
3/8"
3/8"
3/8"
3/8"
Gas tube size - OD
5/8"
5/8"
5/8"
3/4"
3/4"
Cutrting Copper Tube
1/4 Tube
Copper Tube
Flaring Tool
See Table 2
X
Tube Diameter - OD
X (in.)
Inch
Imperial
Rigid
1/4
.051
.028
3/8
.063
.039
5/8
.087
.067
Tube Size (in.)
Torque (ft./lb.)
1/4 13.3
3/8 31.0
5/8 48.0
Flared
Tube
Flare
Nut
Unit
Fitting
