Toshiba RAS-07PKVP-E Service Manual page 67

High Wall, Heat Pump Type
CAUTION
Do not apply excessive force. Otherwise, the nut may
break.
Outer diameter of copper pipe
Dia. 6.35 mm
Dia. 9.52 mm
Dia. 12.7 mm
Tightening torque for connection of flare pipe
The pressure of R410A is higher than R22. (Approx.
1.6 times.) Therefore securely tighten the flare pipes
which connect the outdoor unit and the indoor unit with
the specified tightening torque using a torque wrench.
If any flare pipe is incorrectly connected, it may cause
not only a gas leakage but also trouble in the
refrigeration cycle.
9-4-5. Evacuating
After the piping has been connected to the indoor unit,
perform vacuuming.
NOTE
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.
Using 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 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.
(Unit: N·m)
Tightening torque
14 to 18
(1.4 to 1.8 kgf·m)
33 to 42
(3.3 to 4.2 kgf·m
50 to 62
(5.0 to 6.2 kgf·m)
Flare at indoor
unit side
Flare at outdoor unit
side
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 meters) (assuming a pump
capacity of 27 litres 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.
Compound pressure gauge
–101 kPa
(–76 cmHg)
Handle Lo
Charge hose
(For R410A only)
Connecting
pipe
IMPORTANT POINTS FOR PIPING WORK
• Prevent dust and moisture from entering the pipes.
• Tighten connections carefully (between pipes and
unit).
• Evacuate the air in the connecting pipes using a
VACUUM PUMP.
• Check for gas leaks at all connections.
67
Service Manual
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 liquid side
Packed valve at gas side
Service port
(Valve core (Setting pin))
CAUTION