Refrigerant Piping Installation - mundoclima MVD DC2 Manual De Instalación Y Usuario

First put the
casing into the
unit body lead,
and then connect
to the three plugs.
Move the casing to
the connecting site
to enclose the
connector joint,
and then use the
cable ties to bind
both ends securely.
Note: For detailed panel installation instructions see page 40.
3.3.4 Reinstall the air inlet grille by performing the steps used to
remove the air inlet grille in the reverse order.

4. Refrigerant Piping Installation

4.1 Length and Level Difference Requirements for the Piping Connections
to the Indoor and Outdoor Units
The length and level difference requirements for the refrigerant piping are
different for different indoor and outdoor units. Refer to the installation manual
of the outdoor unit.
4.2 Piping Material and Size
1. Piping material: Copper pipes for air handling.
2. Piping size: Choose and purchase copper pipes that correspond to the
length and size calculated for the selected model in the installation manual
of the outdoor unit and your actual project requirements.
4.3 Piping Layout
1. Seal the two ends of the piping properly before you connect the indoor and
outdoor piping. Once unsealed, connect the piping of the indoor and
outdoor units as quickly as possible to prevent dust or other debris from
entering the piping system via the unsealed ends, as this may cause the
system to malfunction.
2. If the piping needs to go through walls, drill the opening in the wall, and
place accessories like casings and covers for the opening properly.
3. Place the refrigerant connecting piping and the communication wiring for
the indoor and outdoor units together, and bundle them tightly to make sure
air does not enter and condensate to form water that may leak from the
system.
4. Insert the bundled piping and wiring from outside the room through the wall
opening into the room. Be careful when you lay out the piping. Do not
damage the piping.
4.4 Piping Installation
Refer to the installation manual attached with the outdoor unit on installation
of the refrigerant piping for the outdoor unit.
All gas and liquid piping must be properly insulated; otherwise, this may
cause water to leak. Use heat insulation materials that can withstand high
temperatures above 120°C to insulate the gas pipes. In addition, the
insulation of the refrigerant piping should be reinforced (20 mm or thicker) in
situations where there is high temperature and/or high humidity (when part
of refrigerant piping part is higher than 30°C or when the humidity exceeds
RH80%). Otherwise, the surface of the heat insulation material may be
exposed.
Before the works are carried out, verify that the refrigerant is R410A. If the
wrong refrigerant is used, the unit may malfunction.
Other than the specified refrigerant, do not let air or other gases enter the
refrigeration circuit.
If the refrigerant leaks during installation, make sure you fully ventilate the
room.
Use two wrenches when you install or dismantle the piping, a common
wrench and a torque wrench. See Figure 4.1.
Protective
casing
Connector
Figure 3.20
Positions for binding
with cable ties
Figure 3.21
Pipe fittings
Slot the refrigerant piping into the brass nut (accessory 11), and expand the
pipe socket. Refer to the following table for the size of the pipe socket and
the appropriate tightening torque.
External diameter
Tightening torque
(mm)
6.35 14.2-17.2N·m
9.53 32.7-39.9N·m
12.7 49.5-60.3N·m
15.9 61.8-75.4N·m
19.1 97.2-118.6N·m
Caution
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conditions. Excessive torque will damage the socket cap, and the cap will
not be tight if you apply insufficient torque, leading to leakages.
Before the socket cap is installed on the pipe socket, apply some refrigerant
oil on the socket (both inside and outside), and then rotate it three or four
times before you tighten the cap. See Figure 4.3.
Precautions to take when welding the refrigerant pipes
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the air in the pipes. If no nitrogen is filled during welding, a large amount of oxide
film will form inside the piping which may cause the air conditioning system to
malfunction.
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been replaced or refilled.
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reduced to 0.02 MPa using the pressure release valve. See Figure 4.4.
Figure 4.4
4.5 Air Tightness Test
Carry out the air tightness test on the system according to the instructions in the
installation manual of the outdoor unit.
Caution
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valves of the outdoor unit are all closed (maintain the factory defaults).
28
Normal wrench
Torque wrench
Pipe socket cap
Figure 4.1
Flared opening Flared opening
Flared opening
Flared opening
diameter (A)
diameter (A)
8.3-8.7mm
90°± 4
12-12.4mm
A
15.4-15.8mm
18.6-19mm
Figure 4.2
22.9-23.3mm
Apply refrigerant oil
Figure 4.3
1 Copper piping
2 Section being brazed
3 Nitrogen connection
4 Hand valve
5 Pressure-reducing valve
6 Nitrogen
45°± 2
R0.4~0.8