Refrigerant Piping - Toshiba RAV-GM901BTP-E Installation Manual

7

Refrigerant piping

CAUTION
When the refrigerant pipe is long, provide support
brackets at intervals of 2.5 m to 3 m to clamp the
refrigerant pipe. Otherwise, abnormal sound may be
generated.
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.
CAUTION
IMPORTANT 4 POINTS FOR PIPING WORK
1. Reusable mechanical connectors and flared
joints are not allowed indoors. When mechanical
connectors are reused indoors, sealing parts shall
be renewed. When flared joints are reused indoors,
the flare part shall be refabricated.
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)
Pipe size
Pipe size (mm)
Model
Gas side Liquid side
GM90 Ø15.9
27-EN
Connecting refrigerant piping
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 R32 differ from those of
refrigerant R22, the flare tools newly manufactured
for R32 are recommended.
However, the conventional tools can be used by
adjusting projection margin of the copper pipe.
Projection margin in fl aring: B (Unit: mm)
Outer dia. of
Tool used
copper pipe
6.4, 9.5 0.5 to 1.1
12.7, 15.9 0.5 to 1.1
Flaring diameter size: A (Unit: mm)
Outer dia. of copper pipe
6.4
9.5
12.7
Ø9.5
15.9
A
CAUTION
Do not scratch the inner surface of the flared part
when removing burrs.
Flare processing under the condition of scratches
on the inner surface of flare processing part will
cause refrigerant gas leak.
Check that the flared part is not scratched,
deformed, stepped, or flattened, and that there
are no chips adhered or other problems, after flare
processing.
Do not apply refrigerating machine oil to the flare
surface.
* In case of flaring with the conventional flare tool,
pull it out approx. 0.5 mm more than that for R22
to djust to the specified flare size. The copper pipe
gauge is useful for adjusting projection margin size.
The sealed gas was sealed at the atmospheric
Conventional
pressure so when the flare nut is removed, there
tool used
will no "whooshing" sound: This is normal and is not
0.5 to 1.1
indicative of trouble.
1.5 to 2.0
Use two wrenches to connect the indoor unit pipe.
Work using double spanner
Use the tightening torque levels as listed in the
following table.
+0
A
-0.4
Outer dia. of connecting
9.1
pipe (mm)
13.2
6.4
16.6
9.5
19.7
12.7
15.9
Tightening torque of flare pipe connections
Incorrect connections may cause not only a gas leak,
but also a trouble of the refrigeration cycle.
Align the centres 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.
CAUTION
Tightening with an excessive torque may crack the
nut depending on installation conditions.
– 14 –
Evacuation
Perform vacuuming from the charge port of valve of
the outdoor unit by using a vacuum pump.
For details, follow to the Installation Manual attached
to the outdoor unit.
Do not use the refrigerant sealed in the outdoor unit
for evacuation.
REQUIREMENT
For the tools such as charge hose, etc., use those
manufactured exclusively for R32.
Refrigerant amount to be added
For addition of the refrigerant, add refrigerant
"R32" referring to the attached Installation Manual of
outdoor unit.
Use a scale to charge the refrigerant of specified
amount.
REQUIREMENT
Charging an excessive or too little amount of
refrigerant causes a trouble of the compressor.
Charge the refrigerant of specified amount.
A personnel who charged the refrigerant should
write down the pipe length and the added
refrigerant amount in the F-GAS label of the
outdoor unit. It is necessary to fix the compressor
and refrigeration cycle malfunction.
Open the valve fully
Open the valve of the outdoor unit fully. A 4 mm-
hexagonal wrench is required for opening the valve.
For details, refer to the Installation Manual attached to
the outdoor unit.
Tightening torque (N•m)
Gas leak check
14 to 18
Check with a leak detector or soap water whether gas
34 to 42
leaks or not, from the pipe connecting section or cap
49 to 61
of the valve.
63 to 77
REQUIREMENT
Use a leak detector manufactured exclusively for
HFC refrigerant (R32, R134a, R410A, etc.).
28-EN