Toshiba RAS-15EKV-UL Service Manual page 66

10-5. EVACUATING
10-5-1. Evacuating
After the piping has been connected to the indoor unit,
you vacuum both units as once.
Vacuuming
Evacuate the air in the connecting pipes and in the
indoor unit using a vacuum pump. Do not re-use the
refrigerant in the outdoor unit. For details, see the
vacuum pump manual.
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 the air
conditioner, which uses R410A, refrigeration cycle
trouble may happen.)
1. Connect the charge hose from the manifold valve
to the service port of the packed valve at gas side.
2. Connect the charge hose to the port of the vacuum
pump.
3. Open fully the low pressure side handle of the
manifold valve gauge.
4. Operate the vacuum pump to start evacuating.
Perform evacuaion for about 15 minutes if the
piping length is 66 feet (20 m).
(assuming a pump capacity of 27 liters per minute)
Then confirm that the compound pressure gauge
reading is -101 kPa (-76 cmHg).
5. Close the low pressure side valve handle of the
manifold valve gauge.
6. Open fully the valve stem of the packed valves
(both gas and liquid sides).
7. Remove the charging hose from the service port.
8. Securely tighten the caps of packed valves.
Compound pressure gauge
–101 kPa
(–76 cmHg)
Handle Lo
Charge hose
(For R410A only)
Connecting pipe
Packed valve at
liquid side
Service port (Valve core
(Setting pin))
Pressure gauge
Manifold valve
Handle Hi
(Keep full closed)
Charge hose
(For R410A only)
Vacuum pump adapter for
counter-flow prevention
(For R410A only)
Vacuum
pump
Packed valve at gas side
Fig. 10-5-1
5 IMPORTANT POINTS FOR PIPING WORK.
•
(1) Take away dust and moisture (inside of the
connecting pipes).
(2) Tighten the connections (between pipes and
unit).
(3) Evacuate the air in the connecting pipes using
a VACUUM PUMP.
(4) Check gas leak (connected points).
(5) Be sure to fully open the packed valves before
operation.
UNIT DAMAGE HAZARD
•
Failure to follow this caution may result in
equipment damage or improper operation.
Never use the system compressor as a vacuum
pump.
10-5-2. 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
1/2 in. (12.7 mm and smallers)
Securely tighten the valve cap with torque in the
•
following table:
Cap
Valve Rod Cap
Service Port Cap
– 66 –
FILE NO. SVM-13070-2
CAUTION
Size of Hexagon wrench
A = 3/16 in. (4 mm)
Cap Size (H)
43/64 in. - 3/4 in. 10 to 13 Ibf.ft
(H17 - H19)
55/64 in. - 1-3/16 in. 24 to 31 Ibf.ft
(H22 - H30)
35/64 in. 37 to 46 Ibf.ft
(H14)
43/64 in. 10 to 13 Ibf.ft
(H17)
Hexagon wrench
is required.
H
Service Port Cap
Valve Rod Cap
Fig. 10-5-2
.
Torque
(14~18 N·m)
(33~42 N·m)
(50~62 N·m)
(14~18 N·m)
A