Distributor (Gas) Connection Method; How To Install Branch Pipe; Airtight Test, Evacuation And Refrigerant Charging - Mitsubishi Electric PUHY-P-YEM-A Series Installation Manual

[Fig. 9.3.1] (P.5)
<A> (Constant capacity unit)
<C> Compressor
A 10 mm (clearance between units)
C Left side panel
E Oil balance pipe 1 (accessory)
G Flare connection
Tightening torque is 55 N·m (550 kg·cm).
Open and close using a double spanner. Apply a coat of refrigerating ma-
chine oil on both sides of the flare contact surface.
H Oil balance pipe 3 (accessory)
J Through holes for oil balance pipe and transmission cables
K Brazing
• If the oil balance piping for the constant capacity unit from the front of the unit
is taken out, bend the piping as shown in the Fig. 9.3.2. (When doing so, en-
sure that the piping doesn't touch the compressor or other parts.)
[Fig. 9.3.2] (P.6)
<A> (Constant capacity unit)
<C> Control box
A Front panel
B Knock out holes for taking out oil balance pipe from front surface
C Ball valve (oil balance) ø12.7 (flare)
D Oil balance pipe (Bend piping at the site)

9.4. Distributor (gas) connection method

These accessory parts are required to make connection between variable capac-
ity unit and constant capacity unit when using the unit (PUHY-P600/650/700/750).
[Fig. 9.4.1] (P.6) <Parts in Distributor kit>
A Distributor (gas) × 1
C Oil balance pipe 3 × 1
E Pipe cover × 1
G Connecting pipe (OD28.58 - ID28.58) × 1
H Connecting pipe (OD28.58 - ID28.58) × 1
I Connecting pipe (OD44.45 - ID41.28) × 1
J Connecting pipe (OD44.45 - ID38.1) × 1
K Connecting pipe (OD38.1 - ID34.92) × 1
There are two ways to make the connection between variable capacity unit and
constant capacity unit:
1) Taking out piping from frontward.
2) Taking out piping from downward.
[Fig. 9.4.2] (P.6)
F Elbow (OD44.45 - ID44.45)
G Connecting pipe (OD28.58 - ID28.58)
H Connecting pipe (OD28.58 - ID28.58)
I Connecting pipe (OD44.45 - ID41.28)
J Connecting pipe (OD44.45 - ID38.1)
K Connecting pipe (OD38.1 - ID34.92) (For P600 type only)
Step (1)
Braze the elbow F and connecting pipe I, J, K each other outside the unit
according to figure shown above.
For P650 to 750 type: I connecting pipe
For P600 type: J, K connecting pipe
Step (2)
Remove the copper cap and rubber packing attached to the piping and flange of
the distributor (gas).
Braze the assembly in step (1) and connecting pipe G, H to distributor (gas) ac-
cording to figure shown above. When brazing, cool the braze parts of the distribu-
tor side with wet cloth to prevent heating by brazing.
Step (3)
Insert the assembly in step (2) into the variable capacity unit and connect to the
flange of the ball valve (gas side) (Use a socket wrench and socket wrench exten-
sion). When doing so, be sure to mount the included packing between the ball
valve (gas side) and flange of the distributor. Fasten the plate of the distributor
(gas) to the frame of the unit with screw.
<B> (Variable capacity unit)
<D> Control box
B Right side panel
D Ball valve (oil balance) ø12.7 (flare)
F Oil balance pipe 2 (accessory)
I Seal material (2 pieces, included)
L Pipe cover (accessory)
<B> Compressor
<D> Distributor kit
B Oil balance pipe 2 × 1
D Distributor (liquid) × 1
F Elbow (OD44.45 - ID44.45) × 2
Caution:
When brazing, cool with a waste cloth dampened with water so that the flange
and ends of the distributor side piping don't get heated.
- Parts could be damaged if not cooled sufficiently.
Note:
• Distributor kit is attached with constant capacity unit.
• Reset the fin guard of constant capacity unit before the unit works.
• Throw out the support plate that used for fixing the distributor kit.

9.5. How to install branch pipe

For detail, please observe the instruction manual attached to the optional refriger-
ant branch kit.
[Fig. 9.5.1] (P.6)
Å Joint
A To outdoor unit
C Horizontal
E Facing upwards (Facing downwards is not possible)
• Apart from the CMY-Y202-F and CMY-Y302-F gas side, there are no restric-
tions on the posture for attaching joints.
• Ensure that the branch pipes for the CMY-Y202-F and CMY-Y302-F gas side
are attached horizontally or facing upwards (see Fig. 9.5.1).
• There is no limitation on the joint mounting configuration.
• If the diameter of the refrigerant piping selected by the procedures described
on pages 3 to 4 is different from the size of the joint, match the sizes using a
deformed joint. The deformed joint is included with the kit.
[Fig. 9.5.2] (P.7)
Å Header
A To outdoor unit
C Pipe cutter
E Deformed joint
• No restriction is applied to the mounting posture of the header.
• If the diameter of the refrigerant piping selected using the procedures described
on pages 3, 4 and the size of the joint is different, match the sizes using a
deformed joint. The deformed joint is included with the kit.
• When the number of pipes to be connected is smaller than the number of
header branches, install a cap to the unconnected branches. The cap is in-
cluded with the kit.
[Fig. 9.5.3] (P.7)
Å Distributor (liquid) (accessory)
A Field piping
C Constant capacity unit
• Mount the distributor (liquid, attachment part in constant capacity unit) so that
it is within ±15° in relation to the horizontal plane (see Fig. 9.5.3).
Note:
• Distributor (liquid) is attached with distributor kit in constant capacity
unit.
9.6 Airtight test, evacuation and refrigerant
charging
1 Airtight test
Perform with the ball valve of the outdoor unit closed, and pressurize the con-
nection piping and the indoor unit from the service port provided on the ball
valve of the outdoor unit. (Always pressurize from both the gas pipe and the
liquid pipe service ports.)
[Fig. 9.6.1] (P.7)
A Nitrogen gas B To indoor unit
D Lo knob E Hi knob
G Liquid pipe H Gas pipe
J Service port
<For R407C models>
The method of conducting the airtight test is basically the same as for R22 models.
However, since the restrictions have a large affect on deterioration of the refriger-
ating machine oil, always observe them. Also, with nonazeotropic refrigerant (R407C,
etc.), gas leakage causes the composition to change and affects performance.
Therefore, perform the airtightness test cautiously.
B To branch piping or indoor unit
D Within ± 15°
B To indoor unit
D or
B Variable capacity unit
C System analyzer
F Ball valve
I Outdoor unit
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