– 38 –
8-5-3. Vacuum Pumping
INFORMATION
In order to prevent any other refrigerant from being
charged accidentally, each port of the manifold has
been changed in shape.
Differences in Port Size between Conventional
R22 and R410A
Port
size
Manifold for R22
Manifold for R410A
7/16 UNF
1/2 UNF
20 threads per inch
20 threads per inch
AIR PURGE
Evacuate the air in the connecting pipes and in
the indoor unit using vacuum pump.
Do not use the refrigerant in the outdoor unit.
For details, see the manual of vacuum pump.
<Use of vacuum pump>
(1) Connect the charge hose (A) from the manifold
valve to the charge inlet of the gas side packed
valve.
(2) Connect the charge hose (B) to the port of
vacuum pump.
(3) Open fully the low pressure side handle of the
manifold valve.
(4) Operate the vacuum pump.
(5) Close the low pressure side handle of manifold
valve after vacuumizing and stop the vacuum
pump.
Continue vacuumizing more than 15 minutes and
check the pressure gage indicates –0,1MPa
(–76 cmHg).
(6) Open the stems of packed valves A and B all the
way.
(7) Securely tighten the stem cap to each of the
packed valve stems.
VP
Outdoor unit
Charge
hose (B)
Service port
Packed
valve
A
B
C
D
Gas
(Ø9,52)
Liquid
(Ø6,35)
Indoor unit
Lo
Hi
High pressure
side handle
Pressure gage
Manifold valve
Low pressure side handle
Charge hose (A)
Fig. 8-5-5
CAUTION
• KEEP IMPORTANT 4 POINTS FOR
INSTALLATION (PIPING WORK)
(1) Take away dust and moisture (Inside of the
connecting pipes.)
(2) Tight connection (between pipes and unit)
(3) Evacuate the air in the connecting pipes using
VACUUM PUMP.
(4) Check gas leak (connected points)
<Packed Valve Handling Precautions>
• Open the valve stem all the way out; so not try
to open it beyond the stopper.
• Securely tighten the valve stem cap with the
wrench or like.
• Valve stem cap tightening torque is as follows;
Gas pipes side (Ø12,7) : 49 ~ 62 N•m (5,0 ~ 6,2 kgf•m)
Gas pipes side (Ø9,52) : 30 ~ 42 N•m (3,0 ~ 4,2 kgf•m)
Liquid pipe side (Ø6,35) : 16 ~ 18 N•m (1,6 ~ 1,8 kgf•m)
Service port cap
: 9 ~ 10 N•m (0,9 ~ 1,0 kgf•m)
<A5 mm hexagon wrench is required.>
5mm
Flare nut
Stopper
Wrench
Valve body
Valve stem
Service port cap
Service port
Valve stem cap
Note :
Service port at Gas pipes valve only.
Fig. 8-5-6
