Refrigerant Lines - Carrier 38MBRC Series Service Manual

38MBRC: Service Manual

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), consult the long-line applications section 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 is necessary to bury the lines, not more than 36in (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 5 displays the following maximum lengths allowed.
SYSTEM SIZE
Max. outdoor-indoor height difference (OU higher than IU)
Max. outdoor-indoor height difference (IU higher than OU)
Max. Piping length with no additional refrigerant charge
• The charge amount listed in Table 5 is for piping runs up to 26 ft. (8 m).
• For piping runs greater than 26 ft. (8 m), add refrigerant up to the allowable length as specified in Table 6.
Long Line Applications,:
1. No change in line sizing is required.
2. Add refrigerant per Table 6.
TOTAL LINE LENGTH FT.
UNIT SIZE
36-58
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Table 5 — Piping and Refrigerant
Min. Piping Length
Standard Piping Length
Max. Piping Length
Additional refrigerant charge
(between Standard - Max piping length)
Gas Pipe (size-connection type)
Liquid Pipe (size-connection type)
Refrigerant Type
Charge Amount
Table 6 — Additional Charge Table Per Zone
MIN. MAX.
10 213
ft (m)
ft (m)
ft (m)
ft (m)
ft (m)
ft (m)
Oz/ft (g/m)
in (mm)
in (mm)
--
Lbs (kg)
ADDITIONAL CHARGE OZ/FT. (M)
>10-26 (3-8)
None
8
36K 48K 58K
10(3) 10(3) 10 (3)
25(7.5) 25(7.5) 25(7.5)
98(30) 98(30) 98(30)
98(30) 98(30) 98(30)
26(8) 26(8) 26(8)
213(65) 213(65) 213 (65)
0.32(30) 0.32(30) 0.32(30)
5/8(16) 5/8(16) 7/8(22)
3/8(9.52) 3/8(9.52) 3/8(9.52)
R410A R410A R410A
6.72(3.05) 9.26(4.2) 10.58 (4.8)
>26-213 (8-65)
0.32