– 59 –
Service port
(Valve core (Setting pin))
–101 kPa (–76 cmHg)
Handle Lo
Charge hose
(For R410A only)
Charge hose
(For R410A only)
Connecting pipe
Compound pressure gauge
Pressure gauge
Manifold valve
Handle Hi
(Keep full closed)
Vacuum pump adapter for
counter-flow prevention
(For R410A only)
Vacuum
pump
Packed valve at liquid side
Packed valve at gas side
10-5-4. Evacuating
After the piping has been connected to the indoor
unit, perform the air purge.
AIR PURGE
Evacuate the air in the connecting pipes and in
the indoor unit using a vacuum pump.
Do not use the refrigerant in the outdoor unit.
For details, see the vacuum pump manual.
Fig. 10-5-10
CAUTION
• IMPORTANT POINTS FOR PIPING WORK
1. Keep dust and moisture from entering the
pipes.
2. Tighten connections carefully (between pipes
and unit).
3. Evacuate the air in the connecting pipes
using a VACUUM PUMP.
4. Check for gas leaks at all connections.
4mm
Gas side (Ø12.7 mm)
Gas side (Ø9.52 mm)
Liquid side (Ø6.35 mm)
Service port
50 to 62 N•m (5.0 to 6.2 kgf•m)
33 to 42 N•m (3.3 to 4.2 kgf•m)
14 to 18 N•m (1.4 to 1.8 kgf•m)
14 to 18 N•m (1.4 to 1.8 kgf•m)
Hexagonal wrench is required.
Use a vacuum pump
Be sure to use a vacuum pump with counter-flow
prevention function so that oil inside the pump does
not flow back into the air conditioner pipes when the
pump stops. (If oil inside the vacuum pump enters
into the air conditioner circuit which uses R410A,
trouble with the refrigeration system may develop.)
1. Connect the charge hose from the manifold valve
to the service port of the gas side packed valve.
2. Connect the charge hose to the port of the
vacuum pump.
3. Open fully the low pressure side handle of the
gauge manifold valve.
4. Operate the vacuum pump to begin evacuating.
Perform evacuating for about 15 minutes if the
piping length is 20 meters (15 minutes for 20 total
meters) (assuming a pump capacity of 27 liters
per minute).
Confirm that the compound pressure gauge
reading is –101 kPa (–76 cmHg).
5. Close the low pressure valve handle of gauge
manifold.
6. Open fully the valve stem of the packed valves
(both sides of Gas and Liquid).
7. Remove the charging hose from the service port.
8. Securely tighten the caps on the packed valves.
9. Perform steps 1 through 8 above on each con-
nected indoor unit.
Packed valve handling precautions
• Open the valve stem all the way; but do not try to
open it beyond the stopper.
• Securely tighten the valve stem cap with torque in
the following table:
Fig. 10-5-11
Summary of Contents for RAS-3M23GACV-E
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