38MHRC: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
18
Refrigerant Lines
General Refrigerant Line Sizing
1. The outdoor units are shipped with a full charge of R410A refrigerant.
All charges, line sizing, and capacities are based on runs of 25ft. (7.6
m). For runs over 25 ft. (7.6 m), refer to “Long-Line Applications”on
page 18 for the proper charge adjustments.
2. The minimum refrigerant line length between the indoor and outdoor
units is 10 ft. (3 m).
3. Refrigerant lines should not be buried in the ground. If it’s necessary
to bury the lines, not more than 36 in (914 mm) should be buried.
Provide a minimum 6in (152 mm) vertical rise to the service valves
to prevent refrigerant migration.
4. Both lines must be insulated. Use a minimum of 1/2in. (12.7 mm)
thick insulation. Closed-cell insulation is recommended in all
long-line applications.
5. Special consideration should be given to isolating interconnecting
tubing from the building structure. Isolate the tubing so vibration or
noise is not transmitted into the structure.
IMPORTANT: Both refrigerant lines must be insulated separately.
Table 9 lists the maximum lengths allowed.
Table 9 — Piping and Refrigerant Information
Long-Line Applications
1. No change in line sizing is required.
2. Add refrigerant per Table 9.
System
Size
12K(115V) 9K(208/230V) 12K(208/230V) 18K(208/230V) 24K(208/230V)
Piping
Minimum Piping Length ft. (m) 9.8 (3) 9.8 (3) 9.8 (3) 9.8 (3) 9.8 (3)
Standard Piping Length ft. (m) 24.6 (7.5) 24.6 (7.5) 24.6 (7.5) 24.6 (7.5) 24.6 (7.5)
Maximum outdoor-indoor height difference
(OU higher than IU)
ft. (m) 32.8 (10) 32.8 (10) 32.8 (10) 65.6 (20) 82 (25)
Maximum outdoor-indoor height difference
(IU higher than OU)
ft. (m) 32.8 (10) 32.8 (10) 32.8 (10) 65.6 (20) 82 (25)
Maximum Piping Length with no additional
refrigerant charge per System
(Standard Piping length)
ft. (m) 24.6 (7.5) 24.6 (7.5) 24.6 (7.5) 24.6 (7.5) 24.6 (7.5)
Total Maximum Piping Length per system ft. (m) 82 (25) 82 (25) 82 (25) 98.4 (30) 164 (50)
Additional refrigerant charge
(between Standard – Maximum piping length)
Oz/ft
(g/m)
0.161(15) 0.161(15) 0.161(15) 0.161(15) 0.322(30)
Suction Pipe (size - connection type)
In
(mm)
ø1/2” (12.7) ø3/8” (9.52) ø1/2” (12.7) ø1/2” (12.7) ø5/8” (15.9)
Liquid Pipe (size - connection type)
In
(mm)
ø1/4” (6.35) ø1/4” (6.35) ø1/4” (6.35) ø1/4” (6.35) ø3/8” (9.52)
Refrigerant
Refrigerant Type Type R410A R410A R410A R410A R410A
Charge Amount (Heat Pump) lb. (kg) 1.79(0.81) 1.59(0.72) 1.79(0.81) 2.98(1.35) 3.92(1.78)
Charge Amount (Cooling Only) lb. (kg) 1.43 (0.65) - 1.43 (0.65) 1.98(0.9) 3.92 (1.78)
To Next Page
Loading...
Need help?
General
