Air Purge; Vacuum Pump - Toshiba Ras-B13B2Kvg-E1 Service Manual

Evacuating
After the piping has been connected to the indoor unit,
you can perform the air purge together at once.

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
manual of the vacuum pump.
<Using a vacuum pump>
Be sure to use a vacuum pump with counter-flow
prevention function so that inside oil of the pump does
not flow backward into pipes of the air conditioner
when the pump stops. (If oil inside of the vacuum
pump enters into the air conditioner, which use R32,
refrigeration cycle trouble may result.)
1. Connect the charge hose from the manif
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 start evacuating.
Perform evacuating for about 15 minutes if the
piping length is 20 meters. (15 minutes for
20 meters) (assuming a pump capacity of 27 liters
per minute. Then confirm that the compound
pressure gauge reading is -101 kP a (76 cmHg).
5. Close the low pressure side valve handle of gauge
manifold.
6. Open fully the valve stem of the packed valves
(both side of Gas and Liquid).
7. Remove the charging hose from the service port.
8. Securely tighten the caps on the packed valves.
Compound pressure gauge
–101 kPa
(–76 cmHg)
Handle Low
Charge hose
Connecting pipe
Packed valve at gas side
Service port (Valve core (Setting pin))
Packed valve at liquid side
Fig. 10-4-7
old valv
Pressure gauge
Manifold valve
Handle High
(Keep full closed)
Charge hose
Vacuum pump adapter for
counter-f ow prevention
Vacuum
pump
CAUTION
• KEEP IMPORTANT 7 POINTS FOR PIPING WORK
Take away dust and moisture (inside of the
(1)
connecting pipes).
Tighten the connections (between pipes and unit).
(2)
Evacuate the air in the connecting pipes using a
(3)

VACUUM PUMP.

Check gas leak (connected points).
(4)
Be sure to fully open the packed valves before
(5)
operation.
Reusable mechanical connectors and flared joints
(6)
are not allowed indoors. When mechanical
connectors are reused indoors, sealing parts shall
be renewed. When flared joints are reused
indoors, the flare part shall be refabricated.
Don't operate air conditioner in case no
(7)
refrigerant in the system.
e to
<Packed valve handling precautions>
• Open the valve stem all the way out, but do not try
to open it beyond the stopper.
Pipe size of Packed Valve
12.70 mm and smallers
15.88 mm
<Pump down process>
1. Turn off the Air Conditioner system.
2. Connect the charge hose from the manifold valve to the
service port of the packed valve at gas side.
3. Turn on the Air Conditioner system in cooling operation more
than 10 minutes.
4. Check the operating pressure of the system should be normal
value. (Ref. with product specification)
5. Release the valve rod cap of both service valves.
6. Use the Hexagon wrench to turning the valve rod of Liquid
side fully close.
(*Make sure no entering air into the system)
7. Continue operate Air Conditioner system until the gauge of
manifold dropped into the range of 0.5 - 0 kgf/cm
8. Use the Hexagon wrench to turning the valve rod of Gas side
fully close. And turn off the Air Conditioner system
immediately thereafter.
9. Remove the gauge manifold from the service port of the
packed valve.
10. Securely tighten the valve rod cap to the both service valves.
CAUTION
Should be check the compressor operating condition
while pumping down process. It must not any abnormal
sound, more vibration. It is abnormal condition appears
and must turn off the Air Conditioner immediately.
- 61 -
Size of Hexagon wrench
A = 4 mm
A = 5 mm
2