Refrigerant Piping And Evacuating - Toshiba RAV-SM2242DT-E Service Manual

Concealed Duct High Static Pressure
n Heat insulating process
• After drain check, covering the heat insulator for drain connecting section, wrap the drain pipe with heat insulator
(Locally procured) without clearance from the end of the drain pipe connecting port of the indoor unit.
Drain pipe
connecting port
Indoor unit
Installation Manual
Heat insulation (Locally procured)
Thickness 10mm or more
– 21 –
Concealed Duct High Static Pressure
7

REFRIGERANT PIPING AND EVACUATING

n 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 general copper pipes with a wall thickness of
0.8 mm for Ø12.7 mm, and with a wall thickness of
1.0 mm for Ø28.6 mm (half hard).
Do not use any copper pipes with a wall thickness
less than these thicknesses.
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.
REQUIREMENT
When the refrigerant pipe is long, provide support brackets
at intervals of 2.5 to 3 m to clamp the refrigerant pipe.
Otherwise, abnormal sound may be generated.
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)
n Pipe size
Gas side Liquid side
Pipe size
28.6 mm 12.7 mm
Installation Manual
n Liquid side refrigerant pipe
connection
Permissible Piping Length and Height
Difference
They vary according to the outdoor unit.
For details, refer to the Installation Manual attached to
the outdoor unit.
Flaring
• Cut the pipe with a pipe cutter.
Remove burrs completely.
Remaining burrs may cause gas leakage.
• 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.
u Projection margin in flaring: B (Unit: mm)
Rigid (Clutch type)
R410A tool used Conventional tool used
Outer dia. of
copper pipe
R410A R410A
12.7 0 to 0.5 1.5 to 2.0
u Flaring dia. meter size: A (Unit: mm)
A +0
–0.02" (–0.4)
Outer dia. of copper pipe
R410A
12.7 16.6
∗ In case of flaring for R410A with the
conventional flare tool, pull it out 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.
– 22 –
B
A