Refrigerant Piping Work; Insulating Refrigerant Pipes; Drain Piping Work - Mitsubishi Electric CITY MULTI CMB-P-V-GA Manual De Instalación

1. Size of BC controller's end connection piping
[Fig. 4.1.1] (P.3)
Piping portion
Item
PURY-P350 ø19.05 (Brazing)
PURY-P400
PURY-P450
PURY-P500
PURY-P550
ø28.58 (Brazing)
PURY-P600
PURY-P650
Indoor unit side
A To outdoor unit
C BC controller
E Indoor unit
G Combined piping kit (Model name: CMY-R160-J)
H Branch pipe (Model name: CMY-Y102S-G)
I Up to three units for 1 branch hole; total capacity: below 80 (but same in cooling/
heating mode)
The size of BC controller's branch piping is for 50 to 63 type indoor units.
Therefore, if you want to connect indoor units other than the above, do pipe con-
nection following the procedure below.
*1. For connecting 20 to 40 type indoor units
Connect indoor units using the reducers (specials) supplied with BC controllers.
Note:
The flare nuts supplied with BC controllers should be used together.
*2. To connect a unit with a capacity of higher than 141.
After combining two branches using an optionally available piping kit (CMY-R160-
J), connect indoor units.
*3. Connection of plural indoor units with one connection (or joint pipe)
• Total capacity of connectable indoor units: Less than 140 (Less than 250 with
joint pipe)
• Number of connectable indoor units: Maximum 3 Sets
• Branch pipe: Use the branch pipe for CITYMULTI Y Series (CMY-Y102S-G)
• Selection of refrigerant piping ([Fig. 4.1.2] (P.3))
Select the size according to the total capacity of indoor units to be installed
downstream.
Total capacity of indoor units
Below 140
141 to 200
201 to 250
2. Connecting to out side pipes
• For PURY-P350, 400, 450, 500, 550, 600, 650
[Fig. 4.1.2] (P.3)
<A> (high pressure side pipes)
<B> (low pressure side pipes)
A BC controller
B Locally procured pipe ø19.05
C Locally procured pipe ø22.2
D Locally procured pipe ø28.58
EF
Refrigerant connection pipe (accessory)
Note:
• Be sure to use non-oxidative brazing.

4.2. Refrigerant piping work

After connecting the refrigerant pipes of all indoor and outdoor units with the out-
door units' stop valves remained fully closed, evacuate vacuum from the outdoor
units' stop valve service ports.
After completing the above, open the outdoor units' stop valves. This connects the
refrigerant circuit (between outdoor and BC controller) completely.
How to handle stop valves is described on each outdoor unit.
Notes:
• Before tightening the flare nut, apply refrigerating machine oil lightly over
the valve flare surface and its seating surface.
• Use a double spanner for pipe connection.
• After pipe connection, be sure to check that there is no gas leakage,
using a leak detector or soap-and-water solution.
• Before brazing the refrigerant piping, always wrap the piping on the main
body, and the thermal insulation piping, with damp cloths to prevent heat
shrinkage and burning the thermal insulation tubing. Take care to ensure
that the flame does not come into contact with the main body itself.
• Do not use leak-detection additive.
(Unit: mm)
High pressure Low pressure
(liquid) side (gas) side
ø22.2 (Brazing)
ø28.58 (Brazing)
ø9.52 (Flare) ø15.88 (Flare)
B End connection (brazing)
D Reducer (accessory)
F Less than 40
Liquid line Gas line
ø15.88
ø9.52 ø19.05
ø22.2
Warning:
Do not mix anything other than the specified refrigerant (R410A) into the
refrigerating cycle when installing or moving. Mixing air may cause the re-
frigerating cycle to get abnormally high temperature, resulting in a burst.
Caution:
Cut the tip of the indoor unit piping, remove the gas, and then remove the
brazed cap.
[Fig. 4.2.1] (P.3)
A Cut here

4.3. Insulating refrigerant pipes

Be sure to wind heat-resisting polyethylene form of more than 20 mm in thickness
onto both liquid and gas pipes and also put it into the joints between indoor unit
and insulating material so that there will be no gap. Incomplete insulation may
cause a risk of dew drop. Pay careful attention, particularly when insulating above
the ceiling.
[Fig. 4.3.1] (P.3)
A Locally procured insulating material for pipes
B Bind here using band or tape.
D Lap margin: more than 40
F Unit side insulating material

4.4. Drain piping work

1. Drain piping work
• Ensure that the drain piping is downward (pitch of more than 1/100) to the
outdoor (discharge) side. If it is impossible to take any downward pitch, use an
optionally available drain-up mechanism to obtain a downward pitch of more
than 1/100.
• Ensure that any cross-wise drain piping is less than 20 m. If the drain piping is
long, provide metal braces to prevent it from waving. Never provide any air vent
pipe. Otherwise drain may be ejected.
• Connect the supplied drain hose to the discharge port on the unit body. Use
hard vinyl chloride pipes VP-25 (ø32) for drain piping (2). Tighten the supplied
drain hose onto the discharge port using the supplied hose band. (For this, do
not use any adhesive because the drain hose will be removed for service later.)
• Do not have any odor trap around the discharge port.
[Fig. 4.4.1] (P.3)
A: 25 cm
B: 1.5 – 2 m
A Downward pitch of more than 1/100
B Insulating material
D Drain discharge port
F Tie band (accessory)
As shown in 3, install a collecting pipe about 10 cm below the drain ports and
•
give it a downward pitch of more than 1/100. This collecting pipe should be of
VP-30.
• Set the end of drain piping in a place without any risk of odor generation.
• Do not put the end of drain piping into any drain where ionic gases are gener-
ated.
• Although it is free to choose to take out piping in any direction, be sure to
observe the instructions above.
• When using an optionally available drain-up mechanism, follow its instruction
manual for drain piping.
[Fig. 4.4.2] (P.3)
A BC controller
C Collecting pipe
2. Discharge test
After completing drain piping work, open the BC controller panel, fill water, and test
drain discharge. At this moment, check to see that there is no water leakage from
the connections.
3. Insulating drain pipes
Provide sufficient insulation onto the drain pipes just as for refrigerant pipes.
Caution:
Be sure to provide drain piping and heat-insulate it in order to prevent dew
condensation. If there is a deficiency in piping work, it may cause a risk of
water leakage and so wet your property.
B Remove brazed cap
C Do not have any opening.
E Insulating material (field supply)
C Supporting bracket
E Drain hose (200 mm long, accessory)
G Hose band (accessory)
B Indoor unit
D Take as large as possible. About 10 cm.
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