Toshiba RAS-3M26UAV-E, Руководство по обслуживанию

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10-4-6. Refrigerant Piping Connection
CAUTION
KEEP IMPORTANT 4 POINTS FOR PIPING WORK
1. Keep dust and moisture from entering the 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)
‹ Flaring
1. Cut the pipe with a pipe cutter.
Fig. 10-4-10
2. Insert a flare nut into the pipe, and flare the pipe.
As the flaring sizes of R410A differ from those of
refrigerant R22, the flare tools newly
manufactured for R410A are recommended.
However, the conventional tools can be used by
adjusting projection margin of the copper pipe.
• Projection margin in flaring :
B (Unit : mm)
Fig. 10-4-11
Rigid (Clutch type)
Imperial (Wing nut type)
• Flaring size : A (Unit : mm)
Fig. 10-4-12
∗
In the case of flaring for R410A with the conventional
flare tool, pull out it approx. 0.5 mm more than that
for R22 to adjust to the specified flare size.
The copper pipe gauge is useful for adjusting
projection margin size.
10-4-7. Evacuating
After the piping has been connected to all indoor
unit(s), you can perform the air purge together at once.
NOTE
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 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 inside oil of the vacuum pump enters into the air
conditioner which adopts R410A, a trouble of the
refrigeration cycle may be caused.)
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 vacuum
pump.
3. Open fully the low pressure side handle of the
gauge manifold valve.
4. Operate the vacuum pump to start for evacuating.
Perform evacuating for about 40 minutes if the
piping length is total 80 meters.
(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
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.
Fig. 10-4-13
Outer dia. of
copper pipe
R410A tool used Conventional tool used
R410A R22 R410A R22
6.35 0 to 0.5 (Same as left) 1.0 to 1.5 0.5 to 1.0
9.52 0 to 0.5 (Same as left) 1.0 to 1.5 0.5 to 1.0
12.7 0 to 0.5 (Same as left) 1.0 to 1.5 0.5 to 1.0
Outer dia. of copper pipe R410A R22
6.35 1.5 to 2.0 1.0 to 1.5
9.52 1.5 to 2.0 1.0 to 1.5
12.7 2.0 to 2.5 1.5 to 2.0
Outer dia. of copper pipe
A
+0
- 0.4
R410A R22
6.35 9.1 9.0
9.52 13.2 13.0
12.7 16.6 16.2
OK NO GOOD
Obliquity Roughness Warp
AIR PURGE
Compound
pressure gauge
Pressure gauge
Manifold valve
Handle Hi
(Keep full closed)
Charge hose
(For R410A only)
Charge hose
(For R410A only)
–101kPa
(–76cmHg)
Handle Lo
Service port
(Valve core
(Setting pin))
Packed valve
at gas side
Packed valve
at liquid side
Vacuum pump
adapter for
counter-flow prevention
(For R410A only)
Vacuum pump