Carrier 38VMH-1P Service Manual page 7

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Case 2
• Bends in piping cause pressure loss during transportation of refrigerant, so fewer bends increase performance.
• The equivalent length of each bend is 1.64 feet.
• The equivalent length header is 1.64 feet.
• The pipe length difference between each IDU must not exceed 49 feet.
Item
Total piping length
Maximum distance from ODU to farthest IDU
First branch (Header) to farthest IDU
Height between ODU and IDU (ODU above IDU)
Height between ODU and IDU (ODU below IDU)
Height between IDU and IDU
Height between first branch (header) and IDU
Model
38VMB036HDS3-1
38VMB048HDS3-1
38VMB060HDS3-1
*When the length of L1 > 230 feet, the gas pipe should be increased from 5/8" to 3/4" or from 3/4" to 7/8". The pipe adapter must be
located as close as possible to the ODU.
Downstream Indoor Capacity (KBtu/h)
Capacity ≤ 15K
15K < Capacity ≤ 78K
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Fig. 16 —Piping Design (Case 2)
Table 7 —Piping Length
Piping in the Figure
L1 + A + B + C + D
L1 + A, L1 + B, L1 + C, L1 + D
A, B, C, D
H
H'
h1
h2
Table 8 —Selection of "L1"
Gas Pipe
5/8 *
3/4 *
Table 9 —Selection of A~D
Gas Pipe
1/2
5/8
7
Maximum Length Equivalent Length
492
296 328
131
164
131
49
49
Liquid Pipe
3/8
Liquid Pipe
1/4
3/8
A210230
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