Refrigerant Piping - Toshiba RAS-M07U2DVG-E Installation Manual

ML.book Page 16 Wednesday, March 14, 2018 10:28 AM
7

Refrigerant piping

CAUTION
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. Use the flare nut
attached with the indoor unit or
R32/R410A flare nut.
• 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.
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.
Pipe size
Pipe size (mm)
Model RAS-
Gas side Liquid side
07,10,13 type Ø9.5 Ø6.4
16 type
Ø12.7 Ø6.4
22,24 type
EN-31
Connecting refrigerant piping
Flaring
1. Cut the pipe by a pipe cutter.
Remove burrs completely. (Remaining burrs may
cause gas leakage.)
2. Insert a flare nut into the pipe, and flare the pipe. Use
the flare nut provided with the unit or the one used for
the R32/R410A refrigerant. The flaring dimensions for
R32/R410A are different from the ones used for the
conventional R22 refrigerant. A new flare tool
manufactured for use with the R32/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 flaring: B (Unit: mm)
Outer dia. of R32 or R410A Conventional
copper pipe tool used tool used
6.4, 9.5
0 to 0.5 1.0 to 1.5
12.7
Flaring diameter size: A (Unit: mm)
Outer dia. of copper
A +0
–0.4
pipe
6.4 9.1
9.5 13.2
12.7 16.6
– 16 –
• 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.
• The sealed gas was sealed at the atmospheric
pressure so when the flare nut is removed, there will
no "whooshing" sound: This is normal and is not
indicative of trouble.
• Use two wrenches to connect the indoor unit pipe.
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)
9.5 34 to 42 (3.4 to 4.2 kgf•m)
12.7 49 to 61 (4.9 to 6.1 kgf•m)
• Tightening torque of flare pipe connections.
Using a torque wrench, tighten the flare pipe
connecting sections which connect the indoor and
outdoor units of the specified 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.
Installation Manual
Airtight test / Air purge, etc.
For air tightness test, vacuum drying and adding
refrigerant, refer to the Installation Manual attached tothe
outdoor unit.
Open the valve fully
Open the valve of the outdoor unit fully.
Heat insulation process
Apply heat insulation for the pipes separately at liquid
side and gas side.
• For the heat insulation to the pipes at gas side, use the
material with heat-resisting temperature 120 °C or
higher.
• To use the attached heat insulation pipe, apply the
heat insulation to the pipe connecting section of the
indoor unit securely without gap.
REQUIREMENT
• Apply the heat insulation to the pipe connecting
section of the indoor unit securely up to the root
without exposure of the pipe. (The pipe exposed to the
outside causes water leak.)
• Wrap heat insulator with its slits facing up (ceiling
side).
Wrap the pipe with the attached heat insulator
without any gap between the indoor unit.
The seam must be faced
Indoor unit
upward (ceiling side).
Flare nut
Heat insulator
Heat insulation
of the pipe
Union Banding band
pipe
(Locally
(Accessory)
procured)
EN-32