Operation Manual

26
(3) Refrigerant Piping
Maximum Piping Length And Maximum Number Of Bends
When the pipe length becomes too long, both the capacity and reliability drop. As the number of bends in-
creases, system piping resistance to the refrigerant flow increases, thus lowering the cooling capacity, and as
the result the compressor may become defective. Always choose the shortest path and follow the recommen-
dation as tabulated below:
Piping Sizes (Flare Connection Type)
Piping sizes are as follows:
Piping Connection to the Units
• Align the center of the piping and tighten the flare nut sufficiently with fingers.
• Finally tighten the flare nut with torque wrench unit the wrench clicks.
• When tightening the flare nut with torque wrench, ensure the direction for tightening follows the arrow on
the wrench.
Pipe Size (mm/in) Torque (Nm)
6.35 (1/4) 18
9.52 (3/8) 42
12.70 (1/2) 55
15.88 (5/8) 65
19.05 (3/4) 78
R22
R410A
Indoor 15E/ER 20E/ER 25E/ER
Outdoor 15C/CR 18 / 20C/CR 25C/CR 28C/CR 30 / 35C/CR
12 15 15 15 45
588825
10 10 10 10 10
Maximum No. of Bends
Model
28E/ER
Maximum Length, m
Maximum Elevation, m
Model
ALC 15C/CR ALC 18/20C/CR ALC 25C/CR ALC 28C/CR ALC 30C/CR
Liquid (mm/in)
6.35 /
1
/
4
6.35 /
1
/
4
9.52 /
3
/
8
9.52 /
3
/
8
9.52 /
3
/
8
Suction (mm/in)
12.70 /
1
/
2
15.88 /
5
/
8
15.88 /
5
/
8
15.88 /
5
/
8
15.88 /
5
/
8
Model
A5LC 15C/CR A5LC 20C/CR A5LC 25C/CR A5LC 28C/CR A5LC 35C/CR
Liquid (mm/in)
6.35 /
1
/
4
6.35 /
1
/
4
6.35 /
1
/
4
9.52 /
3
/
8
9.52 /
3
/
8
Suction (mm/in)
12.70 /
1
/
2
12.70 /
1
/
2
15.88 /
5
/
8
15.88 /
5
/
8
15.88 /
5
/
8