Refrigerant Piping - Toshiba R410A Service Manual

6

REFRIGERANT PIPING

Refrigerant piping
1. If the outdoor units are to be mounted on a wall,
make sure that the supporting platform is
sufficiently strong. The platform should be
designed and manufactured to maintain its strength
over a long period of time, and sufficient
consideration should be given to ensuring that the
outdoor unit will not fall.
2. Use copper pipe with 0.8 mm or more
thickness.
3. Flare nut and flare works are also different from
those of the conventional refrigerant.
Take out the flare nut attached to the main unit of
the air conditioner, and use it.
CAUTION
IMPORTANT 4 POINTS FOR PIPING WORK
1. Remove dust and moisture from the inside of
the connecting pipes.
2. Tight connection (between pipes and unit)
3. Evacuate the air in the connecting pipes using
VACUUM PUMP.
4. Check the gas leakage. (connected points)
Permissible piping length and heat
The maximum piping length from the outdoor to indoor unit
30 m (Chargeless 20 m)
(RAV-SM561/801AT)
The maximum height difference outdoor/indoor unit
Outdoor unit is above
30 m
Flaring
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)
Rigid (Clutch type)
R410A tool used
Outer diam. of
copper pipe
R410A
6.4 to 15.9 0 to 0.5 (Same as left)
Imperial (Wing nut type)
Outer diam. of copper pipe
6.4 or 9.5
12.7 or 15.9
15 m (Chargeless 15 m)
(RAV-SM1101/1401AT)
Outdoor unit is below
30 m
Conventional tool used
R22 R410A R22
1.0 to 1.5 0.5 to 1.0
R410A R22
1.5 to 2.0 1.0 to 1.5
2.0 to 2.5 1.5 to 2.0
• Flaring dia meter size : A (Unit : mm)
Outer diam. of copper pipe
6.4
9.5
12.7
15.9
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.
Tightening connection
• Do not apply excessive torque. Otherwise, the
nut may crack depending on the conditions.
Outer diam. of copper pipe
6.4 mm (diam.)
9.5 mm (diam.)
12.7 mm (diam.)
15.9 mm (diam.)
• Tightening torque of flare pipe connections
Pressure of R410A becomes higher than that of R22.
(Approx. 1.6 times) Therefore, using a torque
wrench, tighten firmly the flare pipe connecting
sections which connect the
indoor and outdoor units up to
the specified tightening torque.
B
Incorrect connections may
cause not only a gas leakage,
but also a trouble of the
refrigeration cycle or
compressor damage.
Align the centers of the connecting pipes and tighten
the flare nut as far as possible with your fingers. Then
tighten the nut with a spanner and torque wrench as
shown in the figure.
Half union
Externally
threaded side
Use a wrench to secure.
60
+0
A
- 0.4
R410A
9.1
13.2
16.6
19.7
CAUTION
(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)
63 to 77 (6.3 to 7.7 kgf•m)
Flare nut
Internally
threaded side
Use a torque wrench to tighten.
R22
9.0
13.0
16.2
19.4
A
Flare at
indoor
unit side
Flare at
outdoor
unit side