Refrigerant Pipe Installation - Mars Comfort-Aire Century VCD-SA Series Service Manual

Service Manual - VCDxxSA

6. Refrigerant Pipe Installation

6.1 Maximum length and drop height
Ensure that the length of the refrigerant pipe, the number
of bends, and the drop height between the indoor and
outdoor units meets the requirements shown in the
following table.
Max. Length
Capacity(k )
Btu/h
50/164
24~35
65/213.3
36~60
Caution:
1. The capacity test is based on the standard length and
the maximum permissive length is based on the system
reliability.
2. Oil traps
-If oil flows back into the outdoor unit's compressor, this
might cause liquid compression or deterioration of oil
return. Oil traps in the rising gas piping can prevent this.
-An oil trap should be installed every 6m(20ft) of vertical
suction line riser (<36000Btu/h unit).
-An oil trap should be installed every 10m(32.8ft) of
vertical suction line riser (≥36000Btu/h unit).
Indoor unit/
Outdoor unit
6.2 The procedure of connecting pipes
1.Choose the pipe size according to the specification table.
Max. Elevation
(m/ft) (m/ft)
25/82
30/98.4
Indoor unit/
Outdoor unit
6m/20ft (＜36000Btu/h unit)
10m/32.8ft (≥36000Btu/h unit)
6m/20ft (＜36000Btu/h unit)
10m/32.8ft (≥36000Btu/h unit)
 6. Refrigerant Pipe Installation
2.Confirm the cross way of the pipes.
3.Measure the necessary pipe length.
4.Cut the selected pipe with pipe cutter
•
Make the section flat and smooth.
90°
Oblique Rough Warped
5. Insulate the copper pipe
•
Before test operation, the joint parts should not be
heat insulated.
6. Flare the pipe
•
Insert a flare nut into the pipe before flaring the
pipe
•
According to the following table to flare the pipe.
Pipe diameter
Flare dimension A (mm/inch)
Min
(inch(mm))
1/4" (6.35) 8.4/0.33
3/8" (9.52) 13.2/0.52
1/2" (12.7) 16.2/0.64
5/8" (15.9) 19.2/0.76
3/4" (19) 23.2/0.91
7/8" (22) 26.4/1.04
•
After flared the pipe, the opening part must be
seal by end cover or adhesive tape to avoid duct or
exogenous impurity come into the pipe.
7. Drill holes if the pipes need to pass the wall.
8. According to the field condition to bend the pipes so
that it can pass the wall smoothly.
9. Bind and wrap the wire together with the insulated pipe
if necessary.

Flare shape
Max
8.7/0.34
13.5/0.53
90 ° ± 4
16.5/0.65
A
19.7/0.78
R0.4~0.8
23.7/0.93
26.9/1.06