Purging Air and Checking Gas Leakage
If using additional refrigerant, perform air purging from the refrigerant pipes and indoor unit using a vacuum pump,
then charge additional refrigerant.
Use a hexagonal wrench (4 mm) to operate the shut-off valve rod.
All refrigerant pipe joints should be tightened with a torque wrench at the specified tightening torque.
Do not mix any substance other than the specified
refrigerant (R-410A) into the refrigeration cycle.
WARNING
If refrigerant gas leaked during air purging, ventilate
the room as soon as possible.
WARNING
Use a vacuum pump for R-410A exclusively. Using the same vacuum pump for different refrigerants may damage
the vacuum pump or the unit.
To prevent air pollution, a vacuum pump should be used for air purging wherever possible.
(1) Connect projection side (on which worm pin is pressed) of charging hose (which comes from gauge
manifold) to gas shut-off valve’s service port.
(2) Fully open gauge manifold’s low-pressure valve (Lo) and completely close its high-pressure valve (Hi).
(High-pressure valve subsequently requires no operation.)
(3) Apply vacuum pumping. Check that the compound pressure gauge reads – 0.1 MPa (– 76 cm Hg).
Evacuation for
at least 1 hour is recommended.
(4) Close gauge manifold’s low-pressure valve (Lo) and stop vacuum pump.
(Leave as is for 4-5 minutes and make sure the coupling meter needle does not go back.
If it does go back, this may indicate the presence of moisture or leaking from connecting parts. Repeat steps
2 – 4 after checking all connecting parts and slightly loosening the nuts.)
(5) Remove covers from liquid shut-off value and gas shut-off valve.
(6) Turn the liquid shut-off valve’s rod 90 degrees counterclockwise with a hexagonal wrench to open valve.
Close it after 5 seconds, and check for gas leakage.
Using soapy water, check for gas leakage from indoor unit’s flare and outdoor unit’s flare and valve rods.
After the check is complete, wipe all soapy water off.
(7) Disconnect charging hose from gas shut-off valve’s service port, then fully open liquid and gas shut-off
valves.
(Do not attempt to turn valve rod beyond its stop.)
(8) Tighten valve lids and service port caps for the liquid and gas shut-off valves with a torque wrench at the
specified torques. See “3 Refrigerant Piping” for details.
WARNING
7 Flaring the Pipe End
1.
Cut the pipe end with a pipe cutter.
2.
Remove burrs with the cut surface facing
downward so that the chips do not enter
the pipe.
3.
Put the flare nut on the pipe.
4.
Flare the pipe.
5.
Check that the flaring is properly made.
Do not use mineral oil on flared part.
Prevent mineral oil from getting into the system as this would reduce the lifetime
of the units.
Never use piping which has been used for previous installation. Only use parts
which are delivered with the unit.
Do never install a drier to this R-410A unit in order to guarantee its lifetime.
The drying material may dissolve and damage the system.
Incomplete flaring may cause refrigerant gas leakage.
WARNING
(Cut exactly at right angles.)
Remove burrs
Set exactly at the position shown below.
A
Flaring
Die
Check
Flare’s inner
surface must
be flaw-free.
The pipe end
must be evenly
flared in a
perfect circle.
Make sure
that the flare
nut is fitted.
A
0 ~ 0.5 mm
Clutch-type
Flare tool for R-410A
1.0 ~ 1.5 mm
Clutch-type
(Rigid-type)
1.5 ~ 2.0 mm
Wing-nut type
(Imperial-type)
Conventional flare tool
77
CS-ME7CKPG / CS-ME10CKPG / CS-ME12CKPG / CS-ME14CKPG / CS-ME18CKPG / CU-2E15CBPG / CU-2E18CBPG / CU-3E23CBPG / CU-4E27CBPG
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