Refrigerant Piping - Toshiba MMU-UP0151SH-E Installation Manual

6

Refrigerant piping

CAUTION CAUTION
Use flare nuts that are included with the unit. Using
different flare nuts may cause refrigerant gas leakage.
 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 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 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)
 Pipe size
Outside diameter size (mm)
Model MMU-
Gas side
UP015, UP018 12.7
UP024 15.9
211-EN
 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.
1.
Remove burrs completely.
Remaining burrs may cause gas leakage.
Insert a flare nut into the pipe, and flare the pipe.
2.
As the flaring sizes of R32 or R410A differ from those
of refrigerant R22, the flare tools newly
manufactured for R32 or 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)
Outside diameter R32 or R410A
size tool used
6.4, 9.5
0 - 0.5
12.7, 15.9
▼ Flaring diameter size: A (Unit: mm)
Outside diameter
+0
A
size –0.4
6.4 9.1
9.5 13.2
12.7 16.6
15.9 19.7
CAUTION CAUTION
Liquid side
• Do not scratch the inner surface of the flared part
6.4
when removing burrs.
9.5
• 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.
Tightening connection
CAUTION CAUTION
Do not apply excessive torque. Otherwise, the nut may
crack depending on the conditions.
Outside diameter size
6.4 mm
9.5 mm
12.7 mm
15.9 mm
▼ 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 centers of the connecting pipes and tighten
B
the flare nut as far as possible with your fingers. Then
tighten the nut with wrenches and torque wrench as
shown in the figure.
Conventional
tool used
1.0 - 1.5
Work using two wrenches
REQUIREMENT
Tightening with an excessive torque may crack the nut
A
depending on installation conditions.
Tighten the nut within the specified tightening torque.
– 106 –
 Airtight test / Air purge, etc.
For air tightness test, vacuum drying and adding
refrigerant, refer to the Installation Manual attached
to the outdoor unit.
CAUTION CAUTION
Unit: N•m
Do not supply power to the indoor unit until the airtight
Tightening torque
test and vacuuming are completed. (If the indoor unit is
powered on, the pulse motor valve is fully closed, which
14 - 18
extends the time for vacuuming.)
34 - 42
49 - 61
68 - 82
 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 upward
Indoor unit
(ceiling side).
Heat insulation
Union
pipe
(Accessory)
Flare nut
Heat insulator
of the pipe
Banding band
(Locally procured)
212-EN