Refrigerant Piping - Toshiba MMC-UP0151HP-E Installation Manual

5

Refrigerant piping

CAUTION
Use fl are nuts that are included with the unit. Using
different fl are nuts may cause refrigerant gas leakage.
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Refrigerant piping
Use the following item for the refrigerant piping.
Material: Seamless phosphorous de-oxidized
copper pipe.
6.35, 9.52 and 12.7 wall thickness 0.8 mm or more.
15.88 wall thickness 1.0 mm or more.
REQUIREMENT
When the refrigerant pipe is long, provide support
brackets at intervals of 2.5 - 3 m to clamp the
refrigerant pipe. Otherwise, abnormal sound may be
generated.
CAUTION
IMPORTANT 4 POINTS FOR PIPING WORK
1. Reusable mechanical connectors and fl ared
joints are not allowed indoors. When mechanical
connectors are reused indoors, sealing parts shall
be renewed.
When fl ared joints are reused indoors, the fl are
part shall be re-fabricated.
2. Tight connection (between pipes and unit)
3. Evacuate the air in the connecting pipes by using
VACUUM PUMP.
4. Check the gas leakage. (Connected points)
15-EN
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Take out direction of
refrigerant pipe
• The refrigerant pipe connecting sections are located
as shown below. (Pipes can be taken out from one of
the three directions.)
• Make a pipe knockout hole, referring to the section
"Pipe knockout hole".
Upper
Back
Right
* When Drain Pump Kit (sold separately) is installed, a
refrigerant pipe can only be taken out from upper direction.
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Permissible piping length and
height difference
They vary depending on the outdoor unit. For details,
refer to the Installation Manual attached to the
outdoor unit.
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Pipe size
Pipe size (mm)
Model MMC-
Gas side Liquid side
UP015 to UP018 Ø12.7 Ø6.4
UP024 to UP056 Ø15.9 Ø9.5
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Connecting refrigerant piping
Flaring
1
Cut the pipe with a pipe cutter.
Remove burrs completely. (Remaining burrs may
cause gas leakage.)
2
Insert a fl are nut into the pipe, and fl are the
pipe.
Use the fl are nut provided with the unit or the
one used for the R32 or R410A refrigerant.
The fl aring dimensions for R32 or R410A are
different from the ones used for the conventional
R22 refrigerant. A new fl are tool manufactured
for use with the R32 or R410A refrigerant is
recommended, but the conventional tool can still
be used if the projection margin of the copper pipe
is adjusted to be as shown in the following table.
Projection margin in fl aring: B (Unit: mm)
Outer dia. of Conventional
Tool used
copper pipe
6.4, 9.5
0 to 0.5
12.7, 15.9
Flaring diameter size: A (Unit: mm)
Outer dia. of copper pipe A
6.4
9.5 13.2
12.7 16.6
15.9 19.7
A
– 8 –
CAUTION
• Do not scratch the inner surface of the fl ared part
when removing burrs.
• Flare processing under the condition of scratches
on the inner surface of fl are processing part will
cause refrigerant gas leak.
• Check that the fl ared part is not scratched,
deformed, stepped, or fl attened, and that there
are no chips adhered or other problems, after fl are
processing.
• Do not apply refrigerating machine oil to the fl are
surface.
* In case of fl aring for R32 or R410A with the
conventional fl are tool, pull it out approx. 0.5 mm
more than that for R22 to adjust to the specifi ed fl are
size. The copper pipe gauge is useful for adjusting
projection margin size.
• The sealed gas was sealed at the atmospheric
pressure so when the fl are nut is removed, there
will no "whooshing" sound: This is normal and is not
indicative of trouble.
tool used
• Use two wrenches to connect the indoor unit pipe.
1.0 to 1.5
Work using double spanner
• Use the tightening torque levels as listed in the table
below.
Outer dia. of
Tightening torque (N•m)
connecting pipe (mm)
6.4 14 to 18 (1.4 to 1.8 kgf•m)
+0
9.5 34 to 42 (3.4 to 4.2 kgf•m)
–0.4
12.7 49 to 61 (4.9 to 6.1 kgf•m)
9.1
15.9 63 to 77 (6.3 to 7.7 kgf•m)
• Tightening torque of fl are pipe connections.
Pressure of R32 or R410A is higher than that of
R22. (Approx. 1.6 times) Therefore, using a torque
wrench, tighten the fl are pipe connecting sections
which connect the indoor and outdoor units of the
specifi ed tightening torque.
Incorrect connections may cause not only a gas leak,
but also a trouble of the refrigeration cycle.
CAUTION
Tightening with an excessive torque may crack the nut
depending on installation conditions.
16-EN