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–29–
• Preparation of Piping
6. Connecting Pipes to the Indoor Unit
Main cause of gas leakage is defect in flaring
work. Carry out correct flaring work in the following
procedure.
work. Carry out correct flaring work in the following
procedure.
1) Cut the pipes and the cable.
■
Use the accessory piping kit or the pipes pur-
chased locally.
chased locally.
■
Measure the distance between the indoor and
the outdoor unit.
the outdoor unit.
■
Cut the pipes a little longer than measured dis-
tance.
tance.
■
Cut the cable 1.5m longer than the pipe length.
2) Burrs removal
■
Completely remove all burrs from the cut cross
section of pipe/tube.
section of pipe/tube.
■
Put the end of the copper tube/pipe to downward
direction as you remove burrs in order to avoid
to let burrs drop in the tubing.
direction as you remove burrs in order to avoid
to let burrs drop in the tubing.
3) Putting nut on
■
Remove flare nuts attached to indoor and out-
door units, than put them on pipe/tube having
completed burr removal.
(Not possible to put them on after flaring work)
door units, than put them on pipe/tube having
completed burr removal.
(Not possible to put them on after flaring work)
4) Flaring work
■
Carry out flaring work using flaring tool as
shown below.
shown below.
Firmly hold copper tube in a bar(or die) as indicat-
ed dimension in the table above.
ed dimension in the table above.
5) Check
■
Compare the flared work with figure below.
■
If flare is noted to be defective, cut off the flared
section and do flaring work again.
section and do flaring work again.
Copper
tube
90
°
Slanted Uneven Rough
Pipe
Reamer
Point down
Flare nut
Copper tube
Bar
Copper pipe
Clamp handle
Red arrow mark
Cone
Yoke
Handle
Bar
"A"
Inclined
Inside is shining without scratches
Smooth all round
Even length
all round
Surface
damaged
Cracked Uneven
thickness
= Improper flaring =
Outside diameter
A
mm
inch
mm
Ø9.52
3/8
0.5~0.8
Ø15.88
5/8
0.8~1.0
Ø19.05
3/4
1.0~1.3
–30–
1. Form the piping according to its routing. Avoid
bending and bending back the same piping point
more than three times. (This will result in hardening
the pipe.)
more than three times. (This will result in hardening
the pipe.)
2. After deforming the piping, align centers of the
union fitting of the indoor unit and the piping, and
tighten them firmly with wrenches.
tighten them firmly with wrenches.
3. Connect pipe to the service valve or ball valve
which is located below the outdoor unit.
4. After completing the piping connection, be sure to
check if there is gas leakage in indoor and outdoor
connection.
connection.
After completing the piping connection, execute vacu-
um drying for the connecting piping and the indoor
unit.
The vacuum drying must be carried out using the ser-
vice ports of both the liquid and gas side valves.
um drying for the connecting piping and the indoor
unit.
The vacuum drying must be carried out using the ser-
vice ports of both the liquid and gas side valves.
Use two wrenches and tighten with regular torque.
Outdoor
unit
Liquid side
Flare connection
Flare connection
Gas side
Indoor
unit
Union
Piping Connection
Vacuum drying
CAUTION
Flare nut fastening torque
Ø6.35mm
1.8kg.mm
Ø9.52mm
4.0kg.mm
Ø12.7mm
5.5kg.mm
Ø15.88mm
6.6kg.mm
Ø19.05mm
6.6kg.mm
Model
Liquid side piping
Gas side piping
24K, 28K, 30K BTU
Ø 9.52mm
Ø15.88mm
36K BTU
Ø 9.52mm
Ø19.05mm
3-way Valve
1. Pumping down
• Procedure
(1) Confirm that both liquid side and gas side
valves are set to the open position.
– Remove the valve stem caps and confirm that
– Remove the valve stem caps and confirm that
the valve stems are in the raised position.
– Be sure to use a hexagonal wrench to operate
the valve stems.
(2) Operate the unit for 10 to 15 minutes.
(3) Stop operation and wait for 3 minutes, then
connect the charge set to the service port of
the 3-way valve.
– Connect the charge hose to the service port.
the 3-way valve.
– Connect the charge hose to the service port.
(4) Air purging of the charge hose.
– Open the low-pressure valve on the charge set
slightly to air purge from the charge hose.
(5) Set the liquid side valve to the closed
position.
(6) Operate the air conditioner in cooling mode
and stop it when the gaug e indicates
1kg/cm
1kg/cm
2
g.
(7) Immediately set the 3-way valve to the closed
position.
– Do this quickly so that the gauge ends up
– Do this quickly so that the gauge ends up
indicating 3 to 5kg/cm
2
g.
(8) Disconnect the charge set, and mount the 2-
way and 3-way valve’s stem nuts and the
service port nut.
– Use torque wrench to tighten the service port
service port nut.
– Use torque wrench to tighten the service port
nut to a torque of 1.8 kg.m.
– Be sure to check for gas leakage.
Lo
Closed
Purge the air
Outdoor unit
Indoor unit
Liquid side
Gas side
CLOSE
Open
3-Way
valve
valve
3-Way
valve
valve
CLOSE
–36–
1) Re-air purging
(Re-installation)
• Procedure
(1) Confirm that both the liquid side valve and the
gas side valve are set to the closed position.
(2) Connect the charge set and a gas cylinder to
the service port of the 3-way valve.
– Leave the valve on the gas cylinder closed.
– Leave the valve on the gas cylinder closed.
(3) Air purging.
– Open the valves on the gas cylinder and the
charge set. Purge the air by loosening the flare
nut on the liquid side valve approximately 45°
for 3 seconds then closing it for 1 minute;
repeat 3 times.
nut on the liquid side valve approximately 45°
for 3 seconds then closing it for 1 minute;
repeat 3 times.
– After purging the air, use a torque wrench to
tighten the flare nut on liquid side valve.
(4) Check for gas leakage.
– Check the flare connections for gas leakage.
(5) Discharge the refrigerant.
– Close the valve on the gas cylinder and
discharge the refrigerant until the gauge
indicates 3 to 5 kg/cm
indicates 3 to 5 kg/cm
2
g.
(6) Disconnect the charg e set and the gas
cylinder, and set the 2-way and 3-way valves
to the open position.
– Be sure to use a hexagonal wrench to operate
to the open position.
– Be sure to use a hexagonal wrench to operate
the valve stems.
(7) Mount the valve stem nuts and the service
port nut.
– Use torque wrench to tighten the service port
– Use torque wrench to tighten the service port
nut to a torque of 1.8 kg.m.
– Be sure to check for gas leakage.
* CAUTION:
Do not leak the gas in the air during Air
Purging.
Purging.
Lo
Closed
OPEN
Closed
Gas cylinder
R22
Outdoor unit
Indoor unit
Liquid side
Gas side
CLOSE
2-Way
valve
valve
3-Way
valve
valve
–37–
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