Refrigerant Piping - Toshiba Carrier MMD-AP0726HP-UL Manuel D'installation

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Refrigerant piping

Refrigerant piping
1. Use general copper pipes with a wall thickness
of 0.03" (0.8 mm) for Ø1/2" (12.7 mm), and with
a wall thickness of 0.04" (1.0 mm) for Ø7/8"
(22.2 mm) (half hard).
Do not use any copper pipes with a wall
thickness less than these thicknesses.
2. Flare nut and are works are also different from
those of the conventional refrigerant.
Take out the are 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 8'2" to 9'10" (2.5 m 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)
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.
Pipe size
Gas side 7/8" (22.2)
Pipe size
(Unit: in (mm))
Liquid side 1/2" (12.7)
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Liquid side refrigerant pipe
connection
Flaring
Cut the pipe with a pipe cutter.
Remove burrs completely.
Remaining burrs may cause gas leakage.
Insert a are nut into the pipe, and are the pipe.
As the aring sizes of R410A differ from those of
refrigerant R22, the are tools newly manufactured
for R410A are recommended.
However, the conventional
B
tools can be used by adjusting
projection margin of the copper
pipe.
q Projection margin in aring: B (Unit: in (mm))
Rigid (Clutch type)
Outer dia. of Conventional
R410A tool used
copper pipe tool used
0 to 0.02" 0.04" to 0.06"
1/2" (12.7)
(0 to 0.5) (1.0 to 1.5)
q Flaring diameter size: A (Unit: in (mm))
+0
Outer dia. of copper pipe
A
-0.02" (–0.4)
1/2" (12.7) 0.65" (16.6)
* In case of aring for R410A with the
A
conventional are tool, pull it out approx.
0.02 (0.5 mm) more than that for R22 to
adjust to the speci ed are size.
The copper pipe gauge is useful for
adjusting projection margin size.
* Use two wrenches to connect the indoor
unit pipe.
Tightening connection
CAUTION
Do not apply excessive torque. Otherwise, the
nut may crack depending on the conditions.
Outer dia. of copper pipe Tightening torque
(in (mm)) (ft•lbs (N•m))
1/2" (12.7) 37 to 46 (50 to 62)
q Tightening torque of are pipe connections
Pressure of R410A is higher than that of R22.
(Approx. 1.6 times) Therefore, using a torque wrench,
tighten the are pipe connecting sections which
connect the indoor and outdoor units of the speci ed
tightening torque.
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 are nut as far as possible with your ngers. Then
tighten the nut with a spanner and torque wrench as
shown in the gure.
Half union Flare nut
Externally
Internally
threaded side
threaded side
Use a wrench to secure. Use a torque wrench to tighten.
REQUIREMENT
Tightening with an excessive torque may crack the
nut depending on installation conditions.
Tighten the nut within the speci ed tightening
torque.
Gas side refrigerant pipe
connection
Turn up the pipe heat insulator to the unit side.
Wrap the pipe with wet cloth.
Turn up pipe heat
insulator
Wet cloth
Remove the all
brazed part.
Remove the cup on the gas side piping by using a
brazing machine.
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CAUTION
Do not burn the pipe heat insulator.
Be careful for the ame, due to the brazing
process on the ceiling.
Remove the cap
Connection pipe
Locally procured
Ø7/8" (22.2 mm)
Braze the connection piping to the joint part.
Braze all around
Turn back the pipe heat insulator and tie up with a
banding band.
Tie up with a banding
band.
Airtight test / air purge, etc.
For air tightness test, adding refrigerant, refer to the
Installation Manual attached to the outdoor unit.
CAUTION
Do not supply power to the indoor unit until the
airtight test and vacuuming are completed. (If the
indoor unit is powered on, the pulse motor valve is
fully closed, which extends the time for vacuuming.)
Open the valve fully
Open the valve of the outdoor unit fully.
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