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14
6. Refrigerant piping work
6.3. Pipe connection
[Fig. 6-3-1] (P.4)
• Apply a thin coat of refrigeration oil on the seat surface of pipe.
• For connection first align the center, then tighten the first 3 to 4 turns of flare nut.
• Use tightening torque table below as a guideline for indoor unit side union joint
section, and tighten using two wrenches. Excessive tightening damages the flare
section.
Warning:
Be careful of flying flare nut! (Internally pressurized)
Remove the flare nut as follows:
1. Loosen the nut until you hear a hissing noise.
2. Do not remove the nut until the gas has been completely released (i.e.,
hissing noise stops).
3. Check that the gas has been completely released, and then remove the nut.
Outdoor unit connection
Connect pipes to stop valve pipe joint of the outdoor unit in the same manner applied
for indoor unit.
• For tightening use a torque wrench or spanner, and use the same tightening torque
applied for indoor unit.
Refrigerant pipe insulation
• After connecting refrigerant piping, insulate the joints (flared joints) with thermal
insulation tubing as shown below.
[Fig. 6-3-2] (P.4)
1. Remove and discard the rubber bung which is inserted in the end of the unit piping.
2. Flare the end of the site refrigerant piping.
3. Pull out the thermal insulation on the site refrigerant piping and replace the
insulation in its original position.
Cautions On Refrigerant Piping
Be sure to use non-oxidative brazing for brazing to ensure that no foreign
matter or moisture enter into the pipe.
Be sure to apply refrigerating machine oil over the flare connection seating
surface and tighten the connection using a double spanner.
Provide a metal brace to support the refrigerant pipe so that no load is
imparted to the indoor unit end pipe. This metal brace should be provided 50
cm [19-11/16 in] away from the indoor unit’s flare connection.
6.4. Purging procedures leak test
6.5. Drain piping work
• Ensure that the drain piping is downward (pitch of more than 1/100) to the outdoor
(discharge) side. Do not provide any trap or irregularity on the way.
• Ensure that any cross-wise drain piping is less than 20 m [65 ft] (excluding the
difference of elevation). If the drain piping is long, provide metal braces to prevent it
from waving. Never provide any air vent pipe. Otherwise drain may be ejected.
• Use a hard vinyl chloride pipe VP-25 (with an external diameter of 32 mm [1-1/4 in])
for drain piping.
• Ensure that collected pipes are 10 cm [3-15/16 in] lower than the unit body’s drain
port.
• Do not provide any odor trap at the drain discharge port.
• Put the end of the drain piping in a position where no odor is generated.
• Do not put the end of the drain piping in any drain where ionic gases are generated.
Copper pipe O.D.
(mm [in])
Flare nut O.D.
(mm [in])
Tightening torque
(N·m)
ø6.35 [1/4] 17 [11/16] 14 - 18
ø9.52 [3/8] 22 [7/8] 34 - 42
ø12.7 [1/2] 26 [1-1/32] 49 - 61
ø15.88 [5/8] 29 [1-5/32] 68 - 82
A Pipe cover (small) (accessory)
B Caution:
Pull out the thermal insulation on the refrigerant piping at the site, insert the flare nut to flare
the end, and replace the insulation in its original position.
Take care to ensure that condensation does not form on exposed copper piping.
C Liquid end of refrigerant piping D Gas end of refrigerant piping
E Site refrigerant piping F Main body
G Pipe cover (large) (accessory) H Thermal insulation (field supply)
I Pull J Flare nut
K Return to original position L Ensure that there is no gap here
M Plate on main body N Band (accessory)
O Ensure that there is no gap here. Place join upwards.
Check the vacuum with the gage manifold valve, then close the gage manifold
valve, and stop the vacuum pump.
Leave it as is for one or two minutes. Make sure the pointer of the gage manifold
valve remains in the same position. Confirm that the pressure gage show
-0.101 MPa (-760 mmHg).
*4 to 5 turns
Remove the gage manifold valve quickly from the service port of the stop valve.
After refrigerant pipes are connected and evacuated, fully open all stop valves on
gas and liquid pipe sides.
Operating without fully opening lowers the performance and causes trouble.
Pipe length:
7 m [23 ft] maximum
No gas charge is needed.
Pipe length exceeding 7 m [23 ft]
Charge the prescribed
amount of gas.
Hexagonal wrench
*Open
*Close
Stop valve
Stop valve
Service port
Stop
valve
Handle
Low
-0.101MPa
(-760 mmHg)
Compound pressure gauge
(for R410A)
Pressure gauge
(for R410A)
Gauge manifold valve
(for R410A)
Handle High
Charge hose
(for R410A)
(or the vacuum
pump with the
function to
prevent the back
flow)
Charge hose
(for R410A)
Adapter for
preventing
the back flow
Window
Vacuum
pump
Tighten the cap to the service port to obtain the initial status.
Retighten the cap
Leak test
PURGING PROCEDURES
Connect the refrigerant pipes (both the liquid and gas pipes) between the indoor
and the outdoor units.
Remove the service port cap of the stop valve on the side of the outdoor unit gas
pipe. (The stop valve will not work in its initial state fresh out of the factory (totally
closed with cap on).)
Connect the gage manifold valve and the vacuum pump to the service port of the
stop valve on the gas pipe side of the outdoor unit.
Run the vacuum pump.
(Vacuumize for more than 15 minutes.)
KJ79P806H01.book 14 ページ ２０２１年１２月１３日 月曜日 午後２時１５分
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