12
11
C
heck if the height difference between indoor unit & outdoor unit and the total length of refrigerant pipe meet
system requirement.
R
efrigerant piping work follows the indoor unit and outdoor unit installation, connect the pipe at the indoor side
first, then the outdoor side.
A
lways keep ends of tubing sealed by placing a cap or covering with tape during installation and do NOT
remove them until you are ready to connect the piping.
B
e sure to insulate any field piping all the way to the piping connection inside the unit. Any exposed piping may
cause condensation or burns if touched.
When the outdoor unit is the top position and the difference of level is over 10m, it is recommended that set
a oil return bend every 5~8m in the gas pipe. The radius of oil reture bend should be over than 10cm.
CAUTION
4.1 FLARING
In case of needing brazing, work with Nitrogen gas blowing.
Improper torque will cause flare damage or gas leaks.
CAUTION
Use separate thermal insulation pipes for gas &
liquid pipes.
The thickness above is a standard of the indoor
temperature of 27°C and humidity of 80%. If install-
ing in an unfavorable conditions such as near bath-
rooms, kitchens, and other similar locations,
reinforce the insulation.
Insulation’s heat-resistance temperature should
be more than 120°C.
Use the adhesives on the connection part of insula-
tion to prevent moisture from entering.
Repair and cover any possible cracks in the insula-
tion, specially check the bent part or hanger of
pipe.
4.2 PIPING WORK
4.2.1 Align the center to tighten the flare nut and finish
connection using two wrenches.
Flare nut
Wrench
Torque wrench
4.2.2 Select the appropriate insulation material for
refrigerant pipe.(Min. 10mm, thermal insulating foam C)
Torque
Tubing size
18 ~ 20 N.m
25 ~ 26 N.m
35 ~ 36 N.m
45 ~ 47 N.m
65 ~ 67 N.m
Φ6.35mm
Φ9.52mm
Φ12.7mm
Φ15.88mm
Φ19.05mm
After the piping work is finished, make sure to check the connection part of each refrigerant pipe and confirm
that there is no gas leak by applying soapy water to them or by using a leak detector specific for HFC refrigerants.
Refer below picture for illustration.
A: Low pressure stop valve B: High pressure stop valve
C & D: Indoor unit flare nuts
Check-point of indoor unit
Check-point of outdoor unit
A
B
C
D
4.3 REFRIGERANT PIPE
NOTE
The refrigerant should be charged from the service port on the outdoor unit’s low pressure valve.
Extended pipe length will affect the capacity and energy efficiency of the unit.
The nominal efficiency is tested based on the pipe length of 5 meter.
When the pipe length is over 5m, the additional refrigerant should be added according to the pipe length.
The max. pipe length is recommended as below.
4.4 AIR EVACUATION
Connect the charge hose from the manifold gauge to the service port of the gas side packed valve.
Connect the charge hose to the port of the vacuum pump.
Fully open the handle Lo of manifold gauge.
Operate the vacuum pump to evacuate air from the system until -76cmHg.
Close the handle Lo of manifold gauge.
Fully open the valve stem of the packed valves.
Remove the charging hose form the service port.
Securely tighten caps of packed valve.
-76 cmHg
Handle Lo
Handle Hi
Charge hose
Charge hose
Vacuum pump
Packed valve
Manifold valve
Compound gauge
Pressure meter
4.5 LEAKAGE TEST
Liquid side:
φ
9.52mm
R410A
Chargeless length
Additional charge per meter
Liquid side:
φ
6.35mm
15g
30g
Minimum length
to reduce abnormal
vibration & noise
3m
R32
5m
12g
24g
4. REFRIGERANT PIPING WORK
4. REFRIGERANT PIPING WORK
Max. height difference(m)
Inverter Model
Capacity(kW)
25
Max. pipe length(m)
10
30
20
40
20
18k
24k
NOTE
Tools required for flaring are pipe cutter, reamer,
flaring tool and pipe holder.
For R32 refrigerant models, the pipe connection
points must be placed outside of room.
90
Oblique Rough Burr
R0.4~0.8
45 °
±2
90 °
± 4
A
4.1.1 Using a pipe cutter to cut the pipe to the
requested length. Ensure that the cut edge
remains at 90° with the side of the pipe.
4.1.2 Use a reamer to remove burrs with the cut
surface downward so that the chips do not
enter the pipe.
4.1.3 Carry out flaring work using flaring tools as
below.
4.1.4 Check if the flaring is properly made. See
incorrectly flared pipes sample below.
Inclined Damaged Surface Cracked Uneven Thickness
Outside diameter
A(mm)
Max
8.7
Φ6.35mm
Φ9.52mm
Φ12.7mm
Φ15.88mm
Φ19.05mm
12.4
15.8
19.0
23.3
8.3
12.0
15.4
18.6
22.9
Min
Refrigerant
* Please use tools for R410A/R32 system respectively.
* Please use tools for R410A/R32 system respectively.
GB
7k/9k/12k
